These are needed for synthesis that doesn't use fusesoc natively.
These were pulled in via 'fusesoc fetch ::uart16550:1.5.5-r1'
Signed-off-by: Michael Neuling <mikey@neuling.org>
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// raminfr.v ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// Inferrable Distributed RAM for FIFOs ////
+//// ////
+//// Known problems (limits): ////
+//// None . ////
+//// ////
+//// To Do: ////
+//// Nothing so far. ////
+//// ////
+//// Author(s): ////
+//// - gorban@opencores.org ////
+//// - Jacob Gorban ////
+//// ////
+//// Created: 2002/07/22 ////
+//// Last Updated: 2002/07/22 ////
+//// (See log for the revision history) ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+// Revision 1.1 2002/07/22 23:02:23 gorban
+// Bug Fixes:
+// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
+// Problem reported by Kenny.Tung.
+// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
+//
+// Improvements:
+// * Made FIFO's as general inferrable memory where possible.
+// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
+// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
+//
+// * Added optional baudrate output (baud_o).
+// This is identical to BAUDOUT* signal on 16550 chip.
+// It outputs 16xbit_clock_rate - the divided clock.
+// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
+//
+
+//Following is the Verilog code for a dual-port RAM with asynchronous read.
+module raminfr
+ (clk, we, a, dpra, di, dpo);
+
+parameter addr_width = 4;
+parameter data_width = 8;
+parameter depth = 16;
+
+input clk;
+input we;
+input [addr_width-1:0] a;
+input [addr_width-1:0] dpra;
+input [data_width-1:0] di;
+//output [data_width-1:0] spo;
+output [data_width-1:0] dpo;
+reg [data_width-1:0] ram [depth-1:0];
+
+wire [data_width-1:0] dpo;
+wire [data_width-1:0] di;
+wire [addr_width-1:0] a;
+wire [addr_width-1:0] dpra;
+
+ always @(posedge clk) begin
+ if (we)
+ ram[a] <= di;
+ end
+// assign spo = ram[a];
+ assign dpo = ram[dpra];
+endmodule
+
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// uart_defines.v ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// Defines of the Core ////
+//// ////
+//// Known problems (limits): ////
+//// None ////
+//// ////
+//// To Do: ////
+//// Nothing. ////
+//// ////
+//// Author(s): ////
+//// - gorban@opencores.org ////
+//// - Jacob Gorban ////
+//// - Igor Mohor (igorm@opencores.org) ////
+//// ////
+//// Created: 2001/05/12 ////
+//// Last Updated: 2001/05/17 ////
+//// (See log for the revision history) ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+// Revision 1.13 2003/06/11 16:37:47 gorban
+// This fixes errors in some cases when data is being read and put to the FIFO at the same time. Patch is submitted by Scott Furman. Update is very recommended.
+//
+// Revision 1.12 2002/07/22 23:02:23 gorban
+// Bug Fixes:
+// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
+// Problem reported by Kenny.Tung.
+// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
+//
+// Improvements:
+// * Made FIFO's as general inferrable memory where possible.
+// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
+// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
+//
+// * Added optional baudrate output (baud_o).
+// This is identical to BAUDOUT* signal on 16550 chip.
+// It outputs 16xbit_clock_rate - the divided clock.
+// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
+//
+// Revision 1.10 2001/12/11 08:55:40 mohor
+// Scratch register define added.
+//
+// Revision 1.9 2001/12/03 21:44:29 gorban
+// Updated specification documentation.
+// Added full 32-bit data bus interface, now as default.
+// Address is 5-bit wide in 32-bit data bus mode.
+// Added wb_sel_i input to the core. It's used in the 32-bit mode.
+// Added debug interface with two 32-bit read-only registers in 32-bit mode.
+// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
+// My small test bench is modified to work with 32-bit mode.
+//
+// Revision 1.8 2001/11/26 21:38:54 gorban
+// Lots of fixes:
+// Break condition wasn't handled correctly at all.
+// LSR bits could lose their values.
+// LSR value after reset was wrong.
+// Timing of THRE interrupt signal corrected.
+// LSR bit 0 timing corrected.
+//
+// Revision 1.7 2001/08/24 21:01:12 mohor
+// Things connected to parity changed.
+// Clock devider changed.
+//
+// Revision 1.6 2001/08/23 16:05:05 mohor
+// Stop bit bug fixed.
+// Parity bug fixed.
+// WISHBONE read cycle bug fixed,
+// OE indicator (Overrun Error) bug fixed.
+// PE indicator (Parity Error) bug fixed.
+// Register read bug fixed.
+//
+// Revision 1.5 2001/05/31 20:08:01 gorban
+// FIFO changes and other corrections.
+//
+// Revision 1.4 2001/05/21 19:12:02 gorban
+// Corrected some Linter messages.
+//
+// Revision 1.3 2001/05/17 18:34:18 gorban
+// First 'stable' release. Should be sythesizable now. Also added new header.
+//
+// Revision 1.0 2001-05-17 21:27:11+02 jacob
+// Initial revision
+//
+//
+
+// Uncomment this if you want your UART to have
+// 16xBaudrate output port.
+// If defined, the enable signal will be used to drive baudrate_o signal
+// It's frequency is 16xbaudrate
+
+// `define UART_HAS_BAUDRATE_OUTPUT
+
+// Register addresses
+`define UART_REG_RB 3'd0 // receiver buffer
+`define UART_REG_TR 3'd0 // transmitter
+`define UART_REG_IE 3'd1 // Interrupt enable
+`define UART_REG_II 3'd2 // Interrupt identification
+`define UART_REG_FC 3'd2 // FIFO control
+`define UART_REG_LC 3'd3 // Line Control
+`define UART_REG_MC 3'd4 // Modem control
+`define UART_REG_LS 3'd5 // Line status
+`define UART_REG_MS 3'd6 // Modem status
+`define UART_REG_SR 3'd7 // Scratch register
+`define UART_REG_DL1 3'd0 // Divisor latch bytes (1-2)
+`define UART_REG_DL2 3'd1
+
+// Interrupt Enable register bits
+`define UART_IE_RDA 0 // Received Data available interrupt
+`define UART_IE_THRE 1 // Transmitter Holding Register empty interrupt
+`define UART_IE_RLS 2 // Receiver Line Status Interrupt
+`define UART_IE_MS 3 // Modem Status Interrupt
+
+// Interrupt Identification register bits
+`define UART_II_IP 0 // Interrupt pending when 0
+`define UART_II_II 3:1 // Interrupt identification
+
+// Interrupt identification values for bits 3:1
+`define UART_II_RLS 3'b011 // Receiver Line Status
+`define UART_II_RDA 3'b010 // Receiver Data available
+`define UART_II_TI 3'b110 // Timeout Indication
+`define UART_II_THRE 3'b001 // Transmitter Holding Register empty
+`define UART_II_MS 3'b000 // Modem Status
+
+// FIFO Control Register bits
+`define UART_FC_TL 1:0 // Trigger level
+
+// FIFO trigger level values
+`define UART_FC_1 2'b00
+`define UART_FC_4 2'b01
+`define UART_FC_8 2'b10
+`define UART_FC_14 2'b11
+
+// Line Control register bits
+`define UART_LC_BITS 1:0 // bits in character
+`define UART_LC_SB 2 // stop bits
+`define UART_LC_PE 3 // parity enable
+`define UART_LC_EP 4 // even parity
+`define UART_LC_SP 5 // stick parity
+`define UART_LC_BC 6 // Break control
+`define UART_LC_DL 7 // Divisor Latch access bit
+
+// Modem Control register bits
+`define UART_MC_DTR 0
+`define UART_MC_RTS 1
+`define UART_MC_OUT1 2
+`define UART_MC_OUT2 3
+`define UART_MC_LB 4 // Loopback mode
+
+// Line Status Register bits
+`define UART_LS_DR 0 // Data ready
+`define UART_LS_OE 1 // Overrun Error
+`define UART_LS_PE 2 // Parity Error
+`define UART_LS_FE 3 // Framing Error
+`define UART_LS_BI 4 // Break interrupt
+`define UART_LS_TFE 5 // Transmit FIFO is empty
+`define UART_LS_TE 6 // Transmitter Empty indicator
+`define UART_LS_EI 7 // Error indicator
+
+// Modem Status Register bits
+`define UART_MS_DCTS 0 // Delta signals
+`define UART_MS_DDSR 1
+`define UART_MS_TERI 2
+`define UART_MS_DDCD 3
+`define UART_MS_CCTS 4 // Complement signals
+`define UART_MS_CDSR 5
+`define UART_MS_CRI 6
+`define UART_MS_CDCD 7
+
+// FIFO parameter defines
+
+`define UART_FIFO_WIDTH 8
+`define UART_FIFO_DEPTH 16
+`define UART_FIFO_POINTER_W 4
+`define UART_FIFO_COUNTER_W 5
+// receiver fifo has width 11 because it has break, parity and framing error bits
+`define UART_FIFO_REC_WIDTH 11
+
+
+`define VERBOSE_WB 0 // All activity on the WISHBONE is recorded
+`define VERBOSE_LINE_STATUS 0 // Details about the lsr (line status register)
+`define FAST_TEST 1 // 64/1024 packets are sent
+
+
+
+
+
+
+
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// uart_receiver.v ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// UART core receiver logic ////
+//// ////
+//// Known problems (limits): ////
+//// None known ////
+//// ////
+//// To Do: ////
+//// Thourough testing. ////
+//// ////
+//// Author(s): ////
+//// - gorban@opencores.org ////
+//// - Jacob Gorban ////
+//// - Igor Mohor (igorm@opencores.org) ////
+//// ////
+//// Created: 2001/05/12 ////
+//// Last Updated: 2001/05/17 ////
+//// (See log for the revision history) ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+// Revision 1.29 2002/07/29 21:16:18 gorban
+// The uart_defines.v file is included again in sources.
+//
+// Revision 1.28 2002/07/22 23:02:23 gorban
+// Bug Fixes:
+// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
+// Problem reported by Kenny.Tung.
+// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
+//
+// Improvements:
+// * Made FIFO's as general inferrable memory where possible.
+// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
+// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
+//
+// * Added optional baudrate output (baud_o).
+// This is identical to BAUDOUT* signal on 16550 chip.
+// It outputs 16xbit_clock_rate - the divided clock.
+// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
+//
+// Revision 1.27 2001/12/30 20:39:13 mohor
+// More than one character was stored in case of break. End of the break
+// was not detected correctly.
+//
+// Revision 1.26 2001/12/20 13:28:27 mohor
+// Missing declaration of rf_push_q fixed.
+//
+// Revision 1.25 2001/12/20 13:25:46 mohor
+// rx push changed to be only one cycle wide.
+//
+// Revision 1.24 2001/12/19 08:03:34 mohor
+// Warnings cleared.
+//
+// Revision 1.23 2001/12/19 07:33:54 mohor
+// Synplicity was having troubles with the comment.
+//
+// Revision 1.22 2001/12/17 14:46:48 mohor
+// overrun signal was moved to separate block because many sequential lsr
+// reads were preventing data from being written to rx fifo.
+// underrun signal was not used and was removed from the project.
+//
+// Revision 1.21 2001/12/13 10:31:16 mohor
+// timeout irq must be set regardless of the rda irq (rda irq does not reset the
+// timeout counter).
+//
+// Revision 1.20 2001/12/10 19:52:05 gorban
+// Igor fixed break condition bugs
+//
+// Revision 1.19 2001/12/06 14:51:04 gorban
+// Bug in LSR[0] is fixed.
+// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers.
+//
+// Revision 1.18 2001/12/03 21:44:29 gorban
+// Updated specification documentation.
+// Added full 32-bit data bus interface, now as default.
+// Address is 5-bit wide in 32-bit data bus mode.
+// Added wb_sel_i input to the core. It's used in the 32-bit mode.
+// Added debug interface with two 32-bit read-only registers in 32-bit mode.
+// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
+// My small test bench is modified to work with 32-bit mode.
+//
+// Revision 1.17 2001/11/28 19:36:39 gorban
+// Fixed: timeout and break didn't pay attention to current data format when counting time
+//
+// Revision 1.16 2001/11/27 22:17:09 gorban
+// Fixed bug that prevented synthesis in uart_receiver.v
+//
+// Revision 1.15 2001/11/26 21:38:54 gorban
+// Lots of fixes:
+// Break condition wasn't handled correctly at all.
+// LSR bits could lose their values.
+// LSR value after reset was wrong.
+// Timing of THRE interrupt signal corrected.
+// LSR bit 0 timing corrected.
+//
+// Revision 1.14 2001/11/10 12:43:21 gorban
+// Logic Synthesis bugs fixed. Some other minor changes
+//
+// Revision 1.13 2001/11/08 14:54:23 mohor
+// Comments in Slovene language deleted, few small fixes for better work of
+// old tools. IRQs need to be fix.
+//
+// Revision 1.12 2001/11/07 17:51:52 gorban
+// Heavily rewritten interrupt and LSR subsystems.
+// Many bugs hopefully squashed.
+//
+// Revision 1.11 2001/10/31 15:19:22 gorban
+// Fixes to break and timeout conditions
+//
+// Revision 1.10 2001/10/20 09:58:40 gorban
+// Small synopsis fixes
+//
+// Revision 1.9 2001/08/24 21:01:12 mohor
+// Things connected to parity changed.
+// Clock devider changed.
+//
+// Revision 1.8 2001/08/23 16:05:05 mohor
+// Stop bit bug fixed.
+// Parity bug fixed.
+// WISHBONE read cycle bug fixed,
+// OE indicator (Overrun Error) bug fixed.
+// PE indicator (Parity Error) bug fixed.
+// Register read bug fixed.
+//
+// Revision 1.6 2001/06/23 11:21:48 gorban
+// DL made 16-bit long. Fixed transmission/reception bugs.
+//
+// Revision 1.5 2001/06/02 14:28:14 gorban
+// Fixed receiver and transmitter. Major bug fixed.
+//
+// Revision 1.4 2001/05/31 20:08:01 gorban
+// FIFO changes and other corrections.
+//
+// Revision 1.3 2001/05/27 17:37:49 gorban
+// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
+//
+// Revision 1.2 2001/05/21 19:12:02 gorban
+// Corrected some Linter messages.
+//
+// Revision 1.1 2001/05/17 18:34:18 gorban
+// First 'stable' release. Should be sythesizable now. Also added new header.
+//
+// Revision 1.0 2001-05-17 21:27:11+02 jacob
+// Initial revision
+//
+//
+
+`include "uart_defines.v"
+
+module uart_receiver (clk, wb_rst_i, lcr, rf_pop, srx_pad_i, enable,
+ counter_t, rf_count, rf_data_out, rf_error_bit, rf_overrun, rx_reset, lsr_mask, rstate, rf_push_pulse);
+
+input clk;
+input wb_rst_i;
+input [7:0] lcr;
+input rf_pop;
+input srx_pad_i;
+input enable;
+input rx_reset;
+input lsr_mask;
+
+output [9:0] counter_t;
+output [`UART_FIFO_COUNTER_W-1:0] rf_count;
+output [`UART_FIFO_REC_WIDTH-1:0] rf_data_out;
+output rf_overrun;
+output rf_error_bit;
+output [3:0] rstate;
+output rf_push_pulse;
+
+reg [3:0] rstate;
+reg [3:0] rcounter16;
+reg [2:0] rbit_counter;
+reg [7:0] rshift; // receiver shift register
+reg rparity; // received parity
+reg rparity_error;
+reg rframing_error; // framing error flag
+reg rparity_xor;
+reg [7:0] counter_b; // counts the 0 (low) signals
+reg rf_push_q;
+
+// RX FIFO signals
+reg [`UART_FIFO_REC_WIDTH-1:0] rf_data_in;
+wire [`UART_FIFO_REC_WIDTH-1:0] rf_data_out;
+wire rf_push_pulse;
+reg rf_push;
+wire rf_pop;
+wire rf_overrun;
+wire [`UART_FIFO_COUNTER_W-1:0] rf_count;
+wire rf_error_bit; // an error (parity or framing) is inside the fifo
+wire break_error = (counter_b == 0);
+
+// RX FIFO instance
+uart_rfifo #(`UART_FIFO_REC_WIDTH) fifo_rx(
+ .clk( clk ),
+ .wb_rst_i( wb_rst_i ),
+ .data_in( rf_data_in ),
+ .data_out( rf_data_out ),
+ .push( rf_push_pulse ),
+ .pop( rf_pop ),
+ .overrun( rf_overrun ),
+ .count( rf_count ),
+ .error_bit( rf_error_bit ),
+ .fifo_reset( rx_reset ),
+ .reset_status(lsr_mask)
+);
+
+wire rcounter16_eq_7 = (rcounter16 == 4'd7);
+wire rcounter16_eq_0 = (rcounter16 == 4'd0);
+
+wire [3:0] rcounter16_minus_1 = rcounter16 - 3'd1;
+
+parameter sr_idle = 4'd0;
+parameter sr_rec_start = 4'd1;
+parameter sr_rec_bit = 4'd2;
+parameter sr_rec_parity = 4'd3;
+parameter sr_rec_stop = 4'd4;
+parameter sr_check_parity = 4'd5;
+parameter sr_rec_prepare = 4'd6;
+parameter sr_end_bit = 4'd7;
+parameter sr_ca_lc_parity = 4'd8;
+parameter sr_wait1 = 4'd9;
+parameter sr_push = 4'd10;
+
+
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ begin
+ rstate <= sr_idle;
+ rcounter16 <= 0;
+ rbit_counter <= 0;
+ rparity_xor <= 1'b0;
+ rframing_error <= 1'b0;
+ rparity_error <= 1'b0;
+ rparity <= 1'b0;
+ rshift <= 0;
+ rf_push <= 1'b0;
+ rf_data_in <= 0;
+ end
+ else
+ if (enable)
+ begin
+ case (rstate)
+ sr_idle : begin
+ rf_push <= 1'b0;
+ rf_data_in <= 0;
+ rcounter16 <= 4'b1110;
+ if (srx_pad_i==1'b0 & ~break_error) // detected a pulse (start bit?)
+ begin
+ rstate <= sr_rec_start;
+ end
+ end
+ sr_rec_start : begin
+ rf_push <= 1'b0;
+ if (rcounter16_eq_7) // check the pulse
+ if (srx_pad_i==1'b1) // no start bit
+ rstate <= sr_idle;
+ else // start bit detected
+ rstate <= sr_rec_prepare;
+ rcounter16 <= rcounter16_minus_1;
+ end
+ sr_rec_prepare:begin
+ case (lcr[/*`UART_LC_BITS*/1:0]) // number of bits in a word
+ 2'b00 : rbit_counter <= 3'b100;
+ 2'b01 : rbit_counter <= 3'b101;
+ 2'b10 : rbit_counter <= 3'b110;
+ 2'b11 : rbit_counter <= 3'b111;
+ endcase
+ if (rcounter16_eq_0)
+ begin
+ rstate <= sr_rec_bit;
+ rcounter16 <= 4'b1110;
+ rshift <= 0;
+ end
+ else
+ rstate <= sr_rec_prepare;
+ rcounter16 <= rcounter16_minus_1;
+ end
+ sr_rec_bit : begin
+ if (rcounter16_eq_0)
+ rstate <= sr_end_bit;
+ if (rcounter16_eq_7) // read the bit
+ case (lcr[/*`UART_LC_BITS*/1:0]) // number of bits in a word
+ 2'b00 : rshift[4:0] <= {srx_pad_i, rshift[4:1]};
+ 2'b01 : rshift[5:0] <= {srx_pad_i, rshift[5:1]};
+ 2'b10 : rshift[6:0] <= {srx_pad_i, rshift[6:1]};
+ 2'b11 : rshift[7:0] <= {srx_pad_i, rshift[7:1]};
+ endcase
+ rcounter16 <= rcounter16_minus_1;
+ end
+ sr_end_bit : begin
+ if (rbit_counter==3'b0) // no more bits in word
+ if (lcr[`UART_LC_PE]) // choose state based on parity
+ rstate <= sr_rec_parity;
+ else
+ begin
+ rstate <= sr_rec_stop;
+ rparity_error <= 1'b0; // no parity - no error :)
+ end
+ else // else we have more bits to read
+ begin
+ rstate <= sr_rec_bit;
+ rbit_counter <= rbit_counter - 3'd1;
+ end
+ rcounter16 <= 4'b1110;
+ end
+ sr_rec_parity: begin
+ if (rcounter16_eq_7) // read the parity
+ begin
+ rparity <= srx_pad_i;
+ rstate <= sr_ca_lc_parity;
+ end
+ rcounter16 <= rcounter16_minus_1;
+ end
+ sr_ca_lc_parity : begin // rcounter equals 6
+ rcounter16 <= rcounter16_minus_1;
+ rparity_xor <= ^{rshift,rparity}; // calculate parity on all incoming data
+ rstate <= sr_check_parity;
+ end
+ sr_check_parity: begin // rcounter equals 5
+ case ({lcr[`UART_LC_EP],lcr[`UART_LC_SP]})
+ 2'b00: rparity_error <= rparity_xor == 0; // no error if parity 1
+ 2'b01: rparity_error <= ~rparity; // parity should sticked to 1
+ 2'b10: rparity_error <= rparity_xor == 1; // error if parity is odd
+ 2'b11: rparity_error <= rparity; // parity should be sticked to 0
+ endcase
+ rcounter16 <= rcounter16_minus_1;
+ rstate <= sr_wait1;
+ end
+ sr_wait1 : if (rcounter16_eq_0)
+ begin
+ rstate <= sr_rec_stop;
+ rcounter16 <= 4'b1110;
+ end
+ else
+ rcounter16 <= rcounter16_minus_1;
+ sr_rec_stop : begin
+ if (rcounter16_eq_7) // read the parity
+ begin
+ rframing_error <= !srx_pad_i; // no framing error if input is 1 (stop bit)
+ rstate <= sr_push;
+ end
+ rcounter16 <= rcounter16_minus_1;
+ end
+ sr_push : begin
+///////////////////////////////////////
+// $display($time, ": received: %b", rf_data_in);
+ if(srx_pad_i | break_error)
+ begin
+ if(break_error)
+ rf_data_in <= {8'b0, 3'b100}; // break input (empty character) to receiver FIFO
+ else
+ rf_data_in <= {rshift, 1'b0, rparity_error, rframing_error};
+ rf_push <= 1'b1;
+ rstate <= sr_idle;
+ end
+ else if(~rframing_error) // There's always a framing before break_error -> wait for break or srx_pad_i
+ begin
+ rf_data_in <= {rshift, 1'b0, rparity_error, rframing_error};
+ rf_push <= 1'b1;
+ rcounter16 <= 4'b1110;
+ rstate <= sr_rec_start;
+ end
+
+ end
+ default : rstate <= sr_idle;
+ endcase
+ end // if (enable)
+end // always of receiver
+
+always @ (posedge clk or posedge wb_rst_i)
+begin
+ if(wb_rst_i)
+ rf_push_q <= 0;
+ else
+ rf_push_q <= rf_push;
+end
+
+assign rf_push_pulse = rf_push & ~rf_push_q;
+
+
+//
+// Break condition detection.
+// Works in conjuction with the receiver state machine
+
+reg [9:0] toc_value; // value to be set to timeout counter
+
+always @(lcr)
+ case (lcr[3:0])
+ 4'b0000 : toc_value = 447; // 7 bits
+ 4'b0100 : toc_value = 479; // 7.5 bits
+ 4'b0001, 4'b1000 : toc_value = 511; // 8 bits
+ 4'b1100 : toc_value = 543; // 8.5 bits
+ 4'b0010, 4'b0101, 4'b1001 : toc_value = 575; // 9 bits
+ 4'b0011, 4'b0110, 4'b1010, 4'b1101 : toc_value = 639; // 10 bits
+ 4'b0111, 4'b1011, 4'b1110 : toc_value = 703; // 11 bits
+ 4'b1111 : toc_value = 767; // 12 bits
+ endcase // case(lcr[3:0])
+
+wire [7:0] brc_value; // value to be set to break counter
+assign brc_value = toc_value[9:2]; // the same as timeout but 1 insead of 4 character times
+
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ counter_b <= 8'd159;
+ else
+ if (srx_pad_i)
+ counter_b <= brc_value; // character time length - 1
+ else
+ if(enable & counter_b != 8'b0) // only work on enable times break not reached.
+ counter_b <= counter_b - 8'd1; // decrement break counter
+end // always of break condition detection
+
+///
+/// Timeout condition detection
+reg [9:0] counter_t; // counts the timeout condition clocks
+
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ counter_t <= 10'd639; // 10 bits for the default 8N1
+ else
+ if(rf_push_pulse || rf_pop || rf_count == 0) // counter is reset when RX FIFO is empty, accessed or above trigger level
+ counter_t <= toc_value;
+ else
+ if (enable && counter_t != 10'b0) // we don't want to underflow
+ counter_t <= counter_t - 10'd1;
+end
+
+endmodule
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// uart_regs.v ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// Registers of the uart 16550 core ////
+//// ////
+//// Known problems (limits): ////
+//// Inserts 1 wait state in all WISHBONE transfers ////
+//// ////
+//// To Do: ////
+//// Nothing or verification. ////
+//// ////
+//// Author(s): ////
+//// - gorban@opencores.org ////
+//// - Jacob Gorban ////
+//// - Igor Mohor (igorm@opencores.org) ////
+//// ////
+//// Created: 2001/05/12 ////
+//// Last Updated: (See log for the revision history ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+// Revision 1.41 2004/05/21 11:44:41 tadejm
+// Added synchronizer flops for RX input.
+//
+// Revision 1.40 2003/06/11 16:37:47 gorban
+// This fixes errors in some cases when data is being read and put to the FIFO at the same time. Patch is submitted by Scott Furman. Update is very recommended.
+//
+// Revision 1.39 2002/07/29 21:16:18 gorban
+// The uart_defines.v file is included again in sources.
+//
+// Revision 1.38 2002/07/22 23:02:23 gorban
+// Bug Fixes:
+// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
+// Problem reported by Kenny.Tung.
+// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
+//
+// Improvements:
+// * Made FIFO's as general inferrable memory where possible.
+// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
+// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
+//
+// * Added optional baudrate output (baud_o).
+// This is identical to BAUDOUT* signal on 16550 chip.
+// It outputs 16xbit_clock_rate - the divided clock.
+// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
+//
+// Revision 1.37 2001/12/27 13:24:09 mohor
+// lsr[7] was not showing overrun errors.
+//
+// Revision 1.36 2001/12/20 13:25:46 mohor
+// rx push changed to be only one cycle wide.
+//
+// Revision 1.35 2001/12/19 08:03:34 mohor
+// Warnings cleared.
+//
+// Revision 1.34 2001/12/19 07:33:54 mohor
+// Synplicity was having troubles with the comment.
+//
+// Revision 1.33 2001/12/17 10:14:43 mohor
+// Things related to msr register changed. After THRE IRQ occurs, and one
+// character is written to the transmit fifo, the detection of the THRE bit in the
+// LSR is delayed for one character time.
+//
+// Revision 1.32 2001/12/14 13:19:24 mohor
+// MSR register fixed.
+//
+// Revision 1.31 2001/12/14 10:06:58 mohor
+// After reset modem status register MSR should be reset.
+//
+// Revision 1.30 2001/12/13 10:09:13 mohor
+// thre irq should be cleared only when being source of interrupt.
+//
+// Revision 1.29 2001/12/12 09:05:46 mohor
+// LSR status bit 0 was not cleared correctly in case of reseting the FCR (rx fifo).
+//
+// Revision 1.28 2001/12/10 19:52:41 gorban
+// Scratch register added
+//
+// Revision 1.27 2001/12/06 14:51:04 gorban
+// Bug in LSR[0] is fixed.
+// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers.
+//
+// Revision 1.26 2001/12/03 21:44:29 gorban
+// Updated specification documentation.
+// Added full 32-bit data bus interface, now as default.
+// Address is 5-bit wide in 32-bit data bus mode.
+// Added wb_sel_i input to the core. It's used in the 32-bit mode.
+// Added debug interface with two 32-bit read-only registers in 32-bit mode.
+// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
+// My small test bench is modified to work with 32-bit mode.
+//
+// Revision 1.25 2001/11/28 19:36:39 gorban
+// Fixed: timeout and break didn't pay attention to current data format when counting time
+//
+// Revision 1.24 2001/11/26 21:38:54 gorban
+// Lots of fixes:
+// Break condition wasn't handled correctly at all.
+// LSR bits could lose their values.
+// LSR value after reset was wrong.
+// Timing of THRE interrupt signal corrected.
+// LSR bit 0 timing corrected.
+//
+// Revision 1.23 2001/11/12 21:57:29 gorban
+// fixed more typo bugs
+//
+// Revision 1.22 2001/11/12 15:02:28 mohor
+// lsr1r error fixed.
+//
+// Revision 1.21 2001/11/12 14:57:27 mohor
+// ti_int_pnd error fixed.
+//
+// Revision 1.20 2001/11/12 14:50:27 mohor
+// ti_int_d error fixed.
+//
+// Revision 1.19 2001/11/10 12:43:21 gorban
+// Logic Synthesis bugs fixed. Some other minor changes
+//
+// Revision 1.18 2001/11/08 14:54:23 mohor
+// Comments in Slovene language deleted, few small fixes for better work of
+// old tools. IRQs need to be fix.
+//
+// Revision 1.17 2001/11/07 17:51:52 gorban
+// Heavily rewritten interrupt and LSR subsystems.
+// Many bugs hopefully squashed.
+//
+// Revision 1.16 2001/11/02 09:55:16 mohor
+// no message
+//
+// Revision 1.15 2001/10/31 15:19:22 gorban
+// Fixes to break and timeout conditions
+//
+// Revision 1.14 2001/10/29 17:00:46 gorban
+// fixed parity sending and tx_fifo resets over- and underrun
+//
+// Revision 1.13 2001/10/20 09:58:40 gorban
+// Small synopsis fixes
+//
+// Revision 1.12 2001/10/19 16:21:40 gorban
+// Changes data_out to be synchronous again as it should have been.
+//
+// Revision 1.11 2001/10/18 20:35:45 gorban
+// small fix
+//
+// Revision 1.10 2001/08/24 21:01:12 mohor
+// Things connected to parity changed.
+// Clock devider changed.
+//
+// Revision 1.9 2001/08/23 16:05:05 mohor
+// Stop bit bug fixed.
+// Parity bug fixed.
+// WISHBONE read cycle bug fixed,
+// OE indicator (Overrun Error) bug fixed.
+// PE indicator (Parity Error) bug fixed.
+// Register read bug fixed.
+//
+// Revision 1.10 2001/06/23 11:21:48 gorban
+// DL made 16-bit long. Fixed transmission/reception bugs.
+//
+// Revision 1.9 2001/05/31 20:08:01 gorban
+// FIFO changes and other corrections.
+//
+// Revision 1.8 2001/05/29 20:05:04 gorban
+// Fixed some bugs and synthesis problems.
+//
+// Revision 1.7 2001/05/27 17:37:49 gorban
+// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
+//
+// Revision 1.6 2001/05/21 19:12:02 gorban
+// Corrected some Linter messages.
+//
+// Revision 1.5 2001/05/17 18:34:18 gorban
+// First 'stable' release. Should be sythesizable now. Also added new header.
+//
+// Revision 1.0 2001-05-17 21:27:11+02 jacob
+// Initial revision
+//
+//
+
+`include "uart_defines.v"
+
+`define UART_DL1 7:0
+`define UART_DL2 15:8
+
+module uart_regs
+#(parameter SIM = 0)
+ (clk,
+ wb_rst_i, wb_addr_i, wb_dat_i, wb_dat_o, wb_we_i, wb_re_i,
+
+// additional signals
+ modem_inputs,
+ stx_pad_o, srx_pad_i,
+
+ rts_pad_o, dtr_pad_o, int_o
+`ifdef UART_HAS_BAUDRATE_OUTPUT
+ , baud_o
+`endif
+
+ );
+
+input clk;
+input wb_rst_i;
+input [2:0] wb_addr_i;
+input [7:0] wb_dat_i;
+output [7:0] wb_dat_o;
+input wb_we_i;
+input wb_re_i;
+
+output stx_pad_o;
+input srx_pad_i;
+
+input [3:0] modem_inputs;
+output rts_pad_o;
+output dtr_pad_o;
+output int_o;
+`ifdef UART_HAS_BAUDRATE_OUTPUT
+output baud_o;
+`endif
+
+wire [3:0] modem_inputs;
+reg enable;
+`ifdef UART_HAS_BAUDRATE_OUTPUT
+assign baud_o = enable; // baud_o is actually the enable signal
+`endif
+
+
+wire stx_pad_o; // received from transmitter module
+wire srx_pad_i;
+wire srx_pad;
+
+reg [7:0] wb_dat_o;
+
+wire [2:0] wb_addr_i;
+wire [7:0] wb_dat_i;
+
+
+reg [3:0] ier;
+reg [3:0] iir;
+reg [1:0] fcr; /// bits 7 and 6 of fcr. Other bits are ignored
+reg [4:0] mcr;
+reg [7:0] lcr;
+reg [7:0] msr;
+reg [15:0] dl; // 32-bit divisor latch
+reg [7:0] scratch; // UART scratch register
+reg start_dlc; // activate dlc on writing to UART_DL1
+reg lsr_mask_d; // delay for lsr_mask condition
+reg msi_reset; // reset MSR 4 lower bits indicator
+//reg threi_clear; // THRE interrupt clear flag
+reg [15:0] dlc; // 32-bit divisor latch counter
+reg int_o;
+
+reg [3:0] trigger_level; // trigger level of the receiver FIFO
+reg rx_reset;
+reg tx_reset;
+
+wire dlab; // divisor latch access bit
+wire cts_pad_i, dsr_pad_i, ri_pad_i, dcd_pad_i; // modem status bits
+wire loopback; // loopback bit (MCR bit 4)
+wire cts, dsr, ri, dcd; // effective signals
+wire cts_c, dsr_c, ri_c, dcd_c; // Complement effective signals (considering loopback)
+wire rts_pad_o, dtr_pad_o; // modem control outputs
+
+// LSR bits wires and regs
+wire [7:0] lsr;
+wire lsr0, lsr1, lsr2, lsr3, lsr4, lsr5, lsr6, lsr7;
+reg lsr0r, lsr1r, lsr2r, lsr3r, lsr4r, lsr5r, lsr6r, lsr7r;
+wire lsr_mask; // lsr_mask
+
+//
+// ASSINGS
+//
+
+assign lsr[7:0] = { lsr7r, lsr6r, lsr5r, lsr4r, lsr3r, lsr2r, lsr1r, lsr0r };
+
+assign {cts_pad_i, dsr_pad_i, ri_pad_i, dcd_pad_i} = modem_inputs;
+assign {cts, dsr, ri, dcd} = ~{cts_pad_i,dsr_pad_i,ri_pad_i,dcd_pad_i};
+
+assign {cts_c, dsr_c, ri_c, dcd_c} = loopback ? {mcr[`UART_MC_RTS],mcr[`UART_MC_DTR],mcr[`UART_MC_OUT1],mcr[`UART_MC_OUT2]}
+ : {cts_pad_i,dsr_pad_i,ri_pad_i,dcd_pad_i};
+
+assign dlab = lcr[`UART_LC_DL];
+assign loopback = mcr[4];
+
+// assign modem outputs
+assign rts_pad_o = mcr[`UART_MC_RTS];
+assign dtr_pad_o = mcr[`UART_MC_DTR];
+
+// Interrupt signals
+wire rls_int; // receiver line status interrupt
+wire rda_int; // receiver data available interrupt
+wire ti_int; // timeout indicator interrupt
+wire thre_int; // transmitter holding register empty interrupt
+wire ms_int; // modem status interrupt
+
+// FIFO signals
+reg tf_push;
+reg rf_pop;
+wire [`UART_FIFO_REC_WIDTH-1:0] rf_data_out;
+wire rf_error_bit; // an error (parity or framing) is inside the fifo
+wire rf_overrun;
+wire rf_push_pulse;
+wire [`UART_FIFO_COUNTER_W-1:0] rf_count;
+wire [`UART_FIFO_COUNTER_W-1:0] tf_count;
+wire [2:0] tstate;
+wire [3:0] rstate;
+wire [9:0] counter_t;
+
+wire thre_set_en; // THRE status is delayed one character time when a character is written to fifo.
+reg [7:0] block_cnt; // While counter counts, THRE status is blocked (delayed one character cycle)
+reg [7:0] block_value; // One character length minus stop bit
+
+// Transmitter Instance
+wire serial_out;
+
+uart_transmitter #(.SIM (SIM)) transmitter(clk, wb_rst_i, lcr, tf_push, wb_dat_i, enable, serial_out, tstate, tf_count, tx_reset, lsr_mask);
+
+ // Synchronizing and sampling serial RX input
+ uart_sync_flops i_uart_sync_flops
+ (
+ .rst_i (wb_rst_i),
+ .clk_i (clk),
+ .stage1_rst_i (1'b0),
+ .stage1_clk_en_i (1'b1),
+ .async_dat_i (srx_pad_i),
+ .sync_dat_o (srx_pad)
+ );
+ defparam i_uart_sync_flops.width = 1;
+ defparam i_uart_sync_flops.init_value = 1'b1;
+
+// handle loopback
+wire serial_in = loopback ? serial_out : srx_pad;
+assign stx_pad_o = loopback ? 1'b1 : serial_out;
+
+// Receiver Instance
+uart_receiver receiver(clk, wb_rst_i, lcr, rf_pop, serial_in, enable,
+ counter_t, rf_count, rf_data_out, rf_error_bit, rf_overrun, rx_reset, lsr_mask, rstate, rf_push_pulse);
+
+
+// Asynchronous reading here because the outputs are sampled in uart_wb.v file
+always @(dl or dlab or ier or iir or scratch
+ or lcr or lsr or msr or rf_data_out or wb_addr_i or wb_re_i) // asynchrounous reading
+begin
+ case (wb_addr_i)
+ `UART_REG_RB : wb_dat_o = dlab ? dl[`UART_DL1] : rf_data_out[10:3];
+ `UART_REG_IE : wb_dat_o = dlab ? dl[`UART_DL2] : {4'd0,ier};
+ `UART_REG_II : wb_dat_o = {4'b1100,iir};
+ `UART_REG_LC : wb_dat_o = lcr;
+ `UART_REG_LS : wb_dat_o = lsr;
+ `UART_REG_MS : wb_dat_o = msr;
+ `UART_REG_SR : wb_dat_o = scratch;
+ default: wb_dat_o = 8'b0; // ??
+ endcase // case(wb_addr_i)
+end // always @ (dl or dlab or ier or iir or scratch...
+
+
+// rf_pop signal handling
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ rf_pop <= 0;
+ else
+ if (rf_pop) // restore the signal to 0 after one clock cycle
+ rf_pop <= 0;
+ else
+ if (wb_re_i && wb_addr_i == `UART_REG_RB && !dlab)
+ rf_pop <= 1; // advance read pointer
+end
+
+wire lsr_mask_condition;
+wire iir_read;
+wire msr_read;
+wire fifo_read;
+wire fifo_write;
+
+assign lsr_mask_condition = (wb_re_i && wb_addr_i == `UART_REG_LS && !dlab);
+assign iir_read = (wb_re_i && wb_addr_i == `UART_REG_II && !dlab);
+assign msr_read = (wb_re_i && wb_addr_i == `UART_REG_MS && !dlab);
+assign fifo_read = (wb_re_i && wb_addr_i == `UART_REG_RB && !dlab);
+assign fifo_write = (wb_we_i && wb_addr_i == `UART_REG_TR && !dlab);
+
+// lsr_mask_d delayed signal handling
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ lsr_mask_d <= 0;
+ else // reset bits in the Line Status Register
+ lsr_mask_d <= lsr_mask_condition;
+end
+
+// lsr_mask is rise detected
+assign lsr_mask = lsr_mask_condition && ~lsr_mask_d;
+
+// msi_reset signal handling
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ msi_reset <= 1;
+ else
+ if (msi_reset)
+ msi_reset <= 0;
+ else
+ if (msr_read)
+ msi_reset <= 1; // reset bits in Modem Status Register
+end
+
+
+//
+// WRITES AND RESETS //
+//
+// Line Control Register
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i)
+ lcr <= 8'b00000011; // 8n1 setting
+ else
+ if (wb_we_i && wb_addr_i==`UART_REG_LC)
+ lcr <= wb_dat_i;
+
+// Interrupt Enable Register or UART_DL2
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i)
+ begin
+ ier <= 4'b0000; // no interrupts after reset
+`ifdef PRESCALER_PRESET_HARD
+ dl[`UART_DL2] <= `PRESCALER_HIGH_PRESET;
+`else
+ dl[`UART_DL2] <= 8'b0;
+`endif
+ end
+ else
+ if (wb_we_i && wb_addr_i==`UART_REG_IE)
+ if (dlab)
+ begin
+ dl[`UART_DL2] <=
+`ifdef PRESCALER_PRESET_HARD
+ dl[`UART_DL2];
+`else
+ wb_dat_i;
+`endif
+ end
+ else
+ ier <= wb_dat_i[3:0]; // ier uses only 4 lsb
+
+
+// FIFO Control Register and rx_reset, tx_reset signals
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) begin
+ fcr <= 2'b11;
+ rx_reset <= 0;
+ tx_reset <= 0;
+ end else
+ if (wb_we_i && wb_addr_i==`UART_REG_FC) begin
+ fcr <= wb_dat_i[7:6];
+ rx_reset <= wb_dat_i[1];
+ tx_reset <= wb_dat_i[2];
+ end else begin
+ rx_reset <= 0;
+ tx_reset <= 0;
+ end
+
+// Modem Control Register
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i)
+ mcr <= 5'b0;
+ else
+ if (wb_we_i && wb_addr_i==`UART_REG_MC)
+ mcr <= wb_dat_i[4:0];
+
+// Scratch register
+// Line Control Register
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i)
+ scratch <= 0; // 8n1 setting
+ else
+ if (wb_we_i && wb_addr_i==`UART_REG_SR)
+ scratch <= wb_dat_i;
+
+// TX_FIFO or UART_DL1
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i)
+ begin
+`ifdef PRESCALER_PRESET_HARD
+ dl[`UART_DL1] <= `PRESCALER_LOW_PRESET;
+`else
+ dl[`UART_DL1] <= 8'b0;
+`endif
+ tf_push <= 1'b0;
+ start_dlc <= 1'b0;
+ end
+ else
+ if (wb_we_i && wb_addr_i==`UART_REG_TR)
+ if (dlab)
+ begin
+`ifdef PRESCALER_PRESET_HARD
+ dl[`UART_DL1] <= dl[`UART_DL1];
+`else
+ dl[`UART_DL1] <= wb_dat_i;
+`endif
+ start_dlc <= 1'b1; // enable DL counter
+ tf_push <= 1'b0;
+ end
+ else
+ begin
+ tf_push <= 1'b1;
+ start_dlc <= 1'b0;
+ end // else: !if(dlab)
+ else
+ begin
+ start_dlc <= 1'b0;
+ tf_push <= 1'b0;
+ end // else: !if(dlab)
+
+// Receiver FIFO trigger level selection logic (asynchronous mux)
+always @(fcr)
+ case (fcr[`UART_FC_TL])
+ 2'b00 : trigger_level = 1;
+ 2'b01 : trigger_level = 4;
+ 2'b10 : trigger_level = 8;
+ 2'b11 : trigger_level = 14;
+ endcase // case(fcr[`UART_FC_TL])
+
+//
+// STATUS REGISTERS //
+//
+
+// Modem Status Register
+reg [3:0] delayed_modem_signals;
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ begin
+ msr <= 0;
+ delayed_modem_signals[3:0] <= 0;
+ end
+ else begin
+ msr[`UART_MS_DDCD:`UART_MS_DCTS] <= msi_reset ? 4'b0 :
+ msr[`UART_MS_DDCD:`UART_MS_DCTS] | ({dcd, ri, dsr, cts} ^ delayed_modem_signals[3:0]);
+ msr[`UART_MS_CDCD:`UART_MS_CCTS] <= {dcd_c, ri_c, dsr_c, cts_c};
+ delayed_modem_signals[3:0] <= {dcd, ri, dsr, cts};
+ end
+end
+
+
+// Line Status Register
+
+// activation conditions
+assign lsr0 = (rf_count==0 && rf_push_pulse); // data in receiver fifo available set condition
+assign lsr1 = rf_overrun; // Receiver overrun error
+assign lsr2 = rf_data_out[1]; // parity error bit
+assign lsr3 = rf_data_out[0]; // framing error bit
+assign lsr4 = rf_data_out[2]; // break error in the character
+assign lsr5 = (tf_count==5'b0 && thre_set_en); // transmitter fifo is empty
+assign lsr6 = (tf_count==5'b0 && thre_set_en && (tstate == /*`S_IDLE */ 0)); // transmitter empty
+assign lsr7 = rf_error_bit | rf_overrun;
+
+// lsr bit0 (receiver data available)
+reg lsr0_d;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr0_d <= 0;
+ else lsr0_d <= lsr0;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr0r <= 0;
+ else lsr0r <= (rf_count==1 && rf_pop && !rf_push_pulse || rx_reset) ? 1'b0 : // deassert condition
+ lsr0r || (lsr0 && ~lsr0_d); // set on rise of lsr0 and keep asserted until deasserted
+
+// lsr bit 1 (receiver overrun)
+reg lsr1_d; // delayed
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr1_d <= 0;
+ else lsr1_d <= lsr1;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr1r <= 0;
+ else lsr1r <= lsr_mask ? 1'b0 : lsr1r || (lsr1 && ~lsr1_d); // set on rise
+
+// lsr bit 2 (parity error)
+reg lsr2_d; // delayed
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr2_d <= 0;
+ else lsr2_d <= lsr2;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr2r <= 0;
+ else lsr2r <= lsr_mask ? 1'b0 : lsr2r || (lsr2 && ~lsr2_d); // set on rise
+
+// lsr bit 3 (framing error)
+reg lsr3_d; // delayed
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr3_d <= 0;
+ else lsr3_d <= lsr3;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr3r <= 0;
+ else lsr3r <= lsr_mask ? 1'b0 : lsr3r || (lsr3 && ~lsr3_d); // set on rise
+
+// lsr bit 4 (break indicator)
+reg lsr4_d; // delayed
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr4_d <= 0;
+ else lsr4_d <= lsr4;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr4r <= 0;
+ else lsr4r <= lsr_mask ? 1'b0 : lsr4r || (lsr4 && ~lsr4_d);
+
+// lsr bit 5 (transmitter fifo is empty)
+reg lsr5_d;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr5_d <= 1;
+ else lsr5_d <= lsr5;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr5r <= 1;
+ else lsr5r <= (fifo_write) ? 1'b0 : lsr5r || (lsr5 && ~lsr5_d);
+
+// lsr bit 6 (transmitter empty indicator)
+reg lsr6_d;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr6_d <= 1;
+ else lsr6_d <= lsr6;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr6r <= 1;
+ else lsr6r <= (fifo_write) ? 1'b0 : lsr6r || (lsr6 && ~lsr6_d);
+
+// lsr bit 7 (error in fifo)
+reg lsr7_d;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr7_d <= 0;
+ else lsr7_d <= lsr7;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) lsr7r <= 0;
+ else lsr7r <= lsr_mask ? 1'b0 : lsr7r || (lsr7 && ~lsr7_d);
+
+// Frequency divider
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ dlc <= 0;
+ else
+ if (start_dlc | ~ (|dlc))
+ dlc <= dl - 16'd1; // preset counter
+ else
+ dlc <= dlc - 16'd1; // decrement counter
+end
+
+// Enable signal generation logic
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ enable <= 1'b0;
+ else
+ if (|dl & ~(|dlc)) // dl>0 & dlc==0
+ enable <= 1'b1;
+ else
+ enable <= 1'b0;
+end
+
+// Delaying THRE status for one character cycle after a character is written to an empty fifo.
+always @(lcr)
+ case (lcr[3:0])
+ 4'b0000 : block_value = 95; // 6 bits
+ 4'b0100 : block_value = 103; // 6.5 bits
+ 4'b0001, 4'b1000 : block_value = 111; // 7 bits
+ 4'b1100 : block_value = 119; // 7.5 bits
+ 4'b0010, 4'b0101, 4'b1001 : block_value = 127; // 8 bits
+ 4'b0011, 4'b0110, 4'b1010, 4'b1101 : block_value = 143; // 9 bits
+ 4'b0111, 4'b1011, 4'b1110 : block_value = 159; // 10 bits
+ 4'b1111 : block_value = 175; // 11 bits
+ endcase // case(lcr[3:0])
+
+// Counting time of one character minus stop bit
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ block_cnt <= 8'd0;
+ else
+ if(lsr5r & fifo_write) // THRE bit set & write to fifo occured
+ block_cnt <= SIM ? 8'd1 : block_value;
+ else
+ if (enable & block_cnt != 8'b0) // only work on enable times
+ block_cnt <= block_cnt - 8'd1; // decrement break counter
+end // always of break condition detection
+
+// Generating THRE status enable signal
+assign thre_set_en = ~(|block_cnt);
+
+
+//
+// INTERRUPT LOGIC
+//
+
+assign rls_int = ier[`UART_IE_RLS] && (lsr[`UART_LS_OE] || lsr[`UART_LS_PE] || lsr[`UART_LS_FE] || lsr[`UART_LS_BI]);
+assign rda_int = ier[`UART_IE_RDA] && (rf_count >= {1'b0,trigger_level});
+assign thre_int = ier[`UART_IE_THRE] && lsr[`UART_LS_TFE];
+assign ms_int = ier[`UART_IE_MS] && (| msr[3:0]);
+assign ti_int = ier[`UART_IE_RDA] && (counter_t == 10'b0) && (|rf_count);
+
+reg rls_int_d;
+reg thre_int_d;
+reg ms_int_d;
+reg ti_int_d;
+reg rda_int_d;
+
+// delay lines
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) rls_int_d <= 0;
+ else rls_int_d <= rls_int;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) rda_int_d <= 0;
+ else rda_int_d <= rda_int;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) thre_int_d <= 0;
+ else thre_int_d <= thre_int;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) ms_int_d <= 0;
+ else ms_int_d <= ms_int;
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) ti_int_d <= 0;
+ else ti_int_d <= ti_int;
+
+// rise detection signals
+
+wire rls_int_rise;
+wire thre_int_rise;
+wire ms_int_rise;
+wire ti_int_rise;
+wire rda_int_rise;
+
+assign rda_int_rise = rda_int & ~rda_int_d;
+assign rls_int_rise = rls_int & ~rls_int_d;
+assign thre_int_rise = thre_int & ~thre_int_d;
+assign ms_int_rise = ms_int & ~ms_int_d;
+assign ti_int_rise = ti_int & ~ti_int_d;
+
+// interrupt pending flags
+reg rls_int_pnd;
+reg rda_int_pnd;
+reg thre_int_pnd;
+reg ms_int_pnd;
+reg ti_int_pnd;
+
+// interrupt pending flags assignments
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) rls_int_pnd <= 0;
+ else
+ rls_int_pnd <= lsr_mask ? 1'b0 : // reset condition
+ rls_int_rise ? 1'b1 : // latch condition
+ rls_int_pnd && ier[`UART_IE_RLS]; // default operation: remove if masked
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) rda_int_pnd <= 0;
+ else
+ rda_int_pnd <= ((rf_count == {1'b0,trigger_level}) && fifo_read) ? 1'b0 : // reset condition
+ rda_int_rise ? 1'b1 : // latch condition
+ rda_int_pnd && ier[`UART_IE_RDA]; // default operation: remove if masked
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) thre_int_pnd <= 0;
+ else
+ thre_int_pnd <= fifo_write || (iir_read & ~iir[`UART_II_IP] & iir[`UART_II_II] == `UART_II_THRE)? 1'b0 :
+ thre_int_rise ? 1'b1 :
+ thre_int_pnd && ier[`UART_IE_THRE];
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) ms_int_pnd <= 0;
+ else
+ ms_int_pnd <= msr_read ? 1'b0 :
+ ms_int_rise ? 1'b1 :
+ ms_int_pnd && ier[`UART_IE_MS];
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) ti_int_pnd <= 0;
+ else
+ ti_int_pnd <= fifo_read ? 1'b0 :
+ ti_int_rise ? 1'b1 :
+ ti_int_pnd && ier[`UART_IE_RDA];
+// end of pending flags
+
+// INT_O logic
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ int_o <= 1'b0;
+ else
+ int_o <=
+ rls_int_pnd ? ~lsr_mask :
+ rda_int_pnd ? 1'b1 :
+ ti_int_pnd ? ~fifo_read :
+ thre_int_pnd ? !(fifo_write & iir_read) :
+ ms_int_pnd ? ~msr_read :
+ 1'd0; // if no interrupt are pending
+end
+
+
+// Interrupt Identification register
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ iir <= 1;
+ else
+ if (rls_int_pnd) // interrupt is pending
+ begin
+ iir[`UART_II_II] <= `UART_II_RLS; // set identification register to correct value
+ iir[`UART_II_IP] <= 1'b0; // and clear the IIR bit 0 (interrupt pending)
+ end else // the sequence of conditions determines priority of interrupt identification
+ if (rda_int)
+ begin
+ iir[`UART_II_II] <= `UART_II_RDA;
+ iir[`UART_II_IP] <= 1'b0;
+ end
+ else if (ti_int_pnd)
+ begin
+ iir[`UART_II_II] <= `UART_II_TI;
+ iir[`UART_II_IP] <= 1'b0;
+ end
+ else if (thre_int_pnd)
+ begin
+ iir[`UART_II_II] <= `UART_II_THRE;
+ iir[`UART_II_IP] <= 1'b0;
+ end
+ else if (ms_int_pnd)
+ begin
+ iir[`UART_II_II] <= `UART_II_MS;
+ iir[`UART_II_IP] <= 1'b0;
+ end else // no interrupt is pending
+ begin
+ iir[`UART_II_II] <= 0;
+ iir[`UART_II_IP] <= 1'b1;
+ end
+end
+
+endmodule
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// uart_rfifo.v (Modified from uart_fifo.v) ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// UART core receiver FIFO ////
+//// ////
+//// To Do: ////
+//// Nothing. ////
+//// ////
+//// Author(s): ////
+//// - gorban@opencores.org ////
+//// - Jacob Gorban ////
+//// - Igor Mohor (igorm@opencores.org) ////
+//// ////
+//// Created: 2001/05/12 ////
+//// Last Updated: 2002/07/22 ////
+//// (See log for the revision history) ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+// Revision 1.3 2003/06/11 16:37:47 gorban
+// This fixes errors in some cases when data is being read and put to the FIFO at the same time. Patch is submitted by Scott Furman. Update is very recommended.
+//
+// Revision 1.2 2002/07/29 21:16:18 gorban
+// The uart_defines.v file is included again in sources.
+//
+// Revision 1.1 2002/07/22 23:02:23 gorban
+// Bug Fixes:
+// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
+// Problem reported by Kenny.Tung.
+// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
+//
+// Improvements:
+// * Made FIFO's as general inferrable memory where possible.
+// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
+// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
+//
+// * Added optional baudrate output (baud_o).
+// This is identical to BAUDOUT* signal on 16550 chip.
+// It outputs 16xbit_clock_rate - the divided clock.
+// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
+//
+// Revision 1.16 2001/12/20 13:25:46 mohor
+// rx push changed to be only one cycle wide.
+//
+// Revision 1.15 2001/12/18 09:01:07 mohor
+// Bug that was entered in the last update fixed (rx state machine).
+//
+// Revision 1.14 2001/12/17 14:46:48 mohor
+// overrun signal was moved to separate block because many sequential lsr
+// reads were preventing data from being written to rx fifo.
+// underrun signal was not used and was removed from the project.
+//
+// Revision 1.13 2001/11/26 21:38:54 gorban
+// Lots of fixes:
+// Break condition wasn't handled correctly at all.
+// LSR bits could lose their values.
+// LSR value after reset was wrong.
+// Timing of THRE interrupt signal corrected.
+// LSR bit 0 timing corrected.
+//
+// Revision 1.12 2001/11/08 14:54:23 mohor
+// Comments in Slovene language deleted, few small fixes for better work of
+// old tools. IRQs need to be fix.
+//
+// Revision 1.11 2001/11/07 17:51:52 gorban
+// Heavily rewritten interrupt and LSR subsystems.
+// Many bugs hopefully squashed.
+//
+// Revision 1.10 2001/10/20 09:58:40 gorban
+// Small synopsis fixes
+//
+// Revision 1.9 2001/08/24 21:01:12 mohor
+// Things connected to parity changed.
+// Clock devider changed.
+//
+// Revision 1.8 2001/08/24 08:48:10 mohor
+// FIFO was not cleared after the data was read bug fixed.
+//
+// Revision 1.7 2001/08/23 16:05:05 mohor
+// Stop bit bug fixed.
+// Parity bug fixed.
+// WISHBONE read cycle bug fixed,
+// OE indicator (Overrun Error) bug fixed.
+// PE indicator (Parity Error) bug fixed.
+// Register read bug fixed.
+//
+// Revision 1.3 2001/05/31 20:08:01 gorban
+// FIFO changes and other corrections.
+//
+// Revision 1.3 2001/05/27 17:37:48 gorban
+// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
+//
+// Revision 1.2 2001/05/17 18:34:18 gorban
+// First 'stable' release. Should be sythesizable now. Also added new header.
+//
+// Revision 1.0 2001-05-17 21:27:12+02 jacob
+// Initial revision
+//
+//
+
+`include "uart_defines.v"
+
+module uart_rfifo (clk,
+ wb_rst_i, data_in, data_out,
+// Control signals
+ push, // push strobe, active high
+ pop, // pop strobe, active high
+// status signals
+ overrun,
+ count,
+ error_bit,
+ fifo_reset,
+ reset_status
+ );
+
+
+// FIFO parameters
+parameter fifo_width = `UART_FIFO_WIDTH;
+parameter fifo_depth = `UART_FIFO_DEPTH;
+parameter fifo_pointer_w = `UART_FIFO_POINTER_W;
+parameter fifo_counter_w = `UART_FIFO_COUNTER_W;
+
+input clk;
+input wb_rst_i;
+input push;
+input pop;
+input [fifo_width-1:0] data_in;
+input fifo_reset;
+input reset_status;
+
+output [fifo_width-1:0] data_out;
+output overrun;
+output [fifo_counter_w-1:0] count;
+output error_bit;
+
+wire [fifo_width-1:0] data_out;
+wire [7:0] data8_out;
+// flags FIFO
+reg [2:0] fifo[fifo_depth-1:0];
+
+// FIFO pointers
+reg [fifo_pointer_w-1:0] top;
+reg [fifo_pointer_w-1:0] bottom;
+
+reg [fifo_counter_w-1:0] count;
+reg overrun;
+
+wire [fifo_pointer_w-1:0] top_plus_1 = top + 4'h1;
+
+raminfr #(fifo_pointer_w,8,fifo_depth) rfifo
+ (.clk(clk),
+ .we(push),
+ .a(top),
+ .dpra(bottom),
+ .di(data_in[fifo_width-1:fifo_width-8]),
+ .dpo(data8_out)
+ );
+
+always @(posedge clk or posedge wb_rst_i) // synchronous FIFO
+begin
+ if (wb_rst_i)
+ begin
+ top <= 0;
+ bottom <= 0;
+ count <= 0;
+ fifo[0] <= 0;
+ fifo[1] <= 0;
+ fifo[2] <= 0;
+ fifo[3] <= 0;
+ fifo[4] <= 0;
+ fifo[5] <= 0;
+ fifo[6] <= 0;
+ fifo[7] <= 0;
+ fifo[8] <= 0;
+ fifo[9] <= 0;
+ fifo[10] <= 0;
+ fifo[11] <= 0;
+ fifo[12] <= 0;
+ fifo[13] <= 0;
+ fifo[14] <= 0;
+ fifo[15] <= 0;
+ end
+ else
+ if (fifo_reset) begin
+ top <= 0;
+ bottom <= 0;
+ count <= 0;
+ fifo[0] <= 0;
+ fifo[1] <= 0;
+ fifo[2] <= 0;
+ fifo[3] <= 0;
+ fifo[4] <= 0;
+ fifo[5] <= 0;
+ fifo[6] <= 0;
+ fifo[7] <= 0;
+ fifo[8] <= 0;
+ fifo[9] <= 0;
+ fifo[10] <= 0;
+ fifo[11] <= 0;
+ fifo[12] <= 0;
+ fifo[13] <= 0;
+ fifo[14] <= 0;
+ fifo[15] <= 0;
+ end
+ else
+ begin
+ case ({push, pop})
+ 2'b10 : if (count<fifo_depth) // overrun condition
+ begin
+ top <= top_plus_1;
+ fifo[top] <= data_in[2:0];
+ count <= count + 5'd1;
+ end
+ 2'b01 : if(count>0)
+ begin
+ fifo[bottom] <= 0;
+ bottom <= bottom + 4'd1;
+ count <= count - 5'd1;
+ end
+ 2'b11 : begin
+ bottom <= bottom + 4'd1;
+ top <= top_plus_1;
+ fifo[top] <= data_in[2:0];
+ end
+ default: ;
+ endcase
+ end
+end // always
+
+always @(posedge clk or posedge wb_rst_i) // synchronous FIFO
+begin
+ if (wb_rst_i)
+ overrun <= 1'b0;
+ else
+ if(fifo_reset | reset_status)
+ overrun <= 1'b0;
+ else
+ if(push & ~pop & (count==fifo_depth))
+ overrun <= 1'b1;
+end // always
+
+
+// please note though that data_out is only valid one clock after pop signal
+assign data_out = {data8_out,fifo[bottom]};
+
+// Additional logic for detection of error conditions (parity and framing) inside the FIFO
+// for the Line Status Register bit 7
+
+wire [2:0] word0 = fifo[0];
+wire [2:0] word1 = fifo[1];
+wire [2:0] word2 = fifo[2];
+wire [2:0] word3 = fifo[3];
+wire [2:0] word4 = fifo[4];
+wire [2:0] word5 = fifo[5];
+wire [2:0] word6 = fifo[6];
+wire [2:0] word7 = fifo[7];
+
+wire [2:0] word8 = fifo[8];
+wire [2:0] word9 = fifo[9];
+wire [2:0] word10 = fifo[10];
+wire [2:0] word11 = fifo[11];
+wire [2:0] word12 = fifo[12];
+wire [2:0] word13 = fifo[13];
+wire [2:0] word14 = fifo[14];
+wire [2:0] word15 = fifo[15];
+
+// a 1 is returned if any of the error bits in the fifo is 1
+assign error_bit = |(word0[2:0] | word1[2:0] | word2[2:0] | word3[2:0] |
+ word4[2:0] | word5[2:0] | word6[2:0] | word7[2:0] |
+ word8[2:0] | word9[2:0] | word10[2:0] | word11[2:0] |
+ word12[2:0] | word13[2:0] | word14[2:0] | word15[2:0] );
+
+endmodule
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// uart_sync_flops.v ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// UART core receiver logic ////
+//// ////
+//// Known problems (limits): ////
+//// None known ////
+//// ////
+//// To Do: ////
+//// Thourough testing. ////
+//// ////
+//// Author(s): ////
+//// - Andrej Erzen (andreje@flextronics.si) ////
+//// - Tadej Markovic (tadejm@flextronics.si) ////
+//// ////
+//// Created: 2004/05/20 ////
+//// Last Updated: 2004/05/20 ////
+//// (See log for the revision history) ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+//
+
+module uart_sync_flops
+(
+ // internal signals
+ rst_i,
+ clk_i,
+ stage1_rst_i,
+ stage1_clk_en_i,
+ async_dat_i,
+ sync_dat_o
+);
+
+parameter width = 1;
+parameter init_value = 1'b0;
+
+input rst_i; // reset input
+input clk_i; // clock input
+input stage1_rst_i; // synchronous reset for stage 1 FF
+input stage1_clk_en_i; // synchronous clock enable for stage 1 FF
+input [width-1:0] async_dat_i; // asynchronous data input
+output [width-1:0] sync_dat_o; // synchronous data output
+
+
+//
+// Interal signal declarations
+//
+
+reg [width-1:0] sync_dat_o;
+reg [width-1:0] flop_0;
+
+
+// first stage
+always @ (posedge clk_i or posedge rst_i)
+begin
+ if (rst_i)
+ flop_0 <= {width{init_value}};
+ else
+ flop_0 <= async_dat_i;
+end
+
+// second stage
+always @ (posedge clk_i or posedge rst_i)
+begin
+ if (rst_i)
+ sync_dat_o <= {width{init_value}};
+ else if (stage1_rst_i)
+ sync_dat_o <= {width{init_value}};
+ else if (stage1_clk_en_i)
+ sync_dat_o <= flop_0;
+end
+
+endmodule
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// uart_tfifo.v ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// UART core transmitter FIFO ////
+//// ////
+//// To Do: ////
+//// Nothing. ////
+//// ////
+//// Author(s): ////
+//// - gorban@opencores.org ////
+//// - Jacob Gorban ////
+//// - Igor Mohor (igorm@opencores.org) ////
+//// ////
+//// Created: 2001/05/12 ////
+//// Last Updated: 2002/07/22 ////
+//// (See log for the revision history) ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+// Revision 1.1 2002/07/22 23:02:23 gorban
+// Bug Fixes:
+// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
+// Problem reported by Kenny.Tung.
+// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
+//
+// Improvements:
+// * Made FIFO's as general inferrable memory where possible.
+// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
+// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
+//
+// * Added optional baudrate output (baud_o).
+// This is identical to BAUDOUT* signal on 16550 chip.
+// It outputs 16xbit_clock_rate - the divided clock.
+// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
+//
+// Revision 1.16 2001/12/20 13:25:46 mohor
+// rx push changed to be only one cycle wide.
+//
+// Revision 1.15 2001/12/18 09:01:07 mohor
+// Bug that was entered in the last update fixed (rx state machine).
+//
+// Revision 1.14 2001/12/17 14:46:48 mohor
+// overrun signal was moved to separate block because many sequential lsr
+// reads were preventing data from being written to rx fifo.
+// underrun signal was not used and was removed from the project.
+//
+// Revision 1.13 2001/11/26 21:38:54 gorban
+// Lots of fixes:
+// Break condition wasn't handled correctly at all.
+// LSR bits could lose their values.
+// LSR value after reset was wrong.
+// Timing of THRE interrupt signal corrected.
+// LSR bit 0 timing corrected.
+//
+// Revision 1.12 2001/11/08 14:54:23 mohor
+// Comments in Slovene language deleted, few small fixes for better work of
+// old tools. IRQs need to be fix.
+//
+// Revision 1.11 2001/11/07 17:51:52 gorban
+// Heavily rewritten interrupt and LSR subsystems.
+// Many bugs hopefully squashed.
+//
+// Revision 1.10 2001/10/20 09:58:40 gorban
+// Small synopsis fixes
+//
+// Revision 1.9 2001/08/24 21:01:12 mohor
+// Things connected to parity changed.
+// Clock devider changed.
+//
+// Revision 1.8 2001/08/24 08:48:10 mohor
+// FIFO was not cleared after the data was read bug fixed.
+//
+// Revision 1.7 2001/08/23 16:05:05 mohor
+// Stop bit bug fixed.
+// Parity bug fixed.
+// WISHBONE read cycle bug fixed,
+// OE indicator (Overrun Error) bug fixed.
+// PE indicator (Parity Error) bug fixed.
+// Register read bug fixed.
+//
+// Revision 1.3 2001/05/31 20:08:01 gorban
+// FIFO changes and other corrections.
+//
+// Revision 1.3 2001/05/27 17:37:48 gorban
+// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
+//
+// Revision 1.2 2001/05/17 18:34:18 gorban
+// First 'stable' release. Should be sythesizable now. Also added new header.
+//
+// Revision 1.0 2001-05-17 21:27:12+02 jacob
+// Initial revision
+//
+//
+
+`include "uart_defines.v"
+
+module uart_tfifo (clk,
+ wb_rst_i, data_in, data_out,
+// Control signals
+ push, // push strobe, active high
+ pop, // pop strobe, active high
+// status signals
+ overrun,
+ count,
+ fifo_reset,
+ reset_status
+ );
+
+
+// FIFO parameters
+parameter fifo_width = `UART_FIFO_WIDTH;
+parameter fifo_depth = `UART_FIFO_DEPTH;
+parameter fifo_pointer_w = `UART_FIFO_POINTER_W;
+parameter fifo_counter_w = `UART_FIFO_COUNTER_W;
+
+input clk;
+input wb_rst_i;
+input push;
+input pop;
+input [fifo_width-1:0] data_in;
+input fifo_reset;
+input reset_status;
+
+output [fifo_width-1:0] data_out;
+output overrun;
+output [fifo_counter_w-1:0] count;
+
+wire [fifo_width-1:0] data_out;
+
+// FIFO pointers
+reg [fifo_pointer_w-1:0] top;
+reg [fifo_pointer_w-1:0] bottom;
+
+reg [fifo_counter_w-1:0] count;
+reg overrun;
+wire [fifo_pointer_w-1:0] top_plus_1 = top + 4'd1;
+
+raminfr #(fifo_pointer_w,fifo_width,fifo_depth) tfifo
+ (.clk(clk),
+ .we(push),
+ .a(top),
+ .dpra(bottom),
+ .di(data_in),
+ .dpo(data_out)
+ );
+
+
+always @(posedge clk or posedge wb_rst_i) // synchronous FIFO
+begin
+ if (wb_rst_i)
+ begin
+ top <= 0;
+ bottom <= 0;
+ count <= 0;
+ end
+ else
+ if (fifo_reset) begin
+ top <= 0;
+ bottom <= 0;
+ count <= 0;
+ end
+ else
+ begin
+ case ({push, pop})
+ 2'b10 : if (count<fifo_depth) // overrun condition
+ begin
+ top <= top_plus_1;
+ count <= count + 5'd1;
+ end
+ 2'b01 : if(count>0)
+ begin
+ bottom <= bottom + 4'd1;
+ count <= count - 5'd1;
+ end
+ 2'b11 : begin
+ bottom <= bottom + 4'd1;
+ top <= top_plus_1;
+ end
+ default: ;
+ endcase
+ end
+end // always
+
+always @(posedge clk or posedge wb_rst_i) // synchronous FIFO
+begin
+ if (wb_rst_i)
+ overrun <= 1'b0;
+ else
+ if(fifo_reset | reset_status)
+ overrun <= 1'b0;
+ else
+ if(push & (count==fifo_depth))
+ overrun <= 1'b1;
+end // always
+
+endmodule
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// uart_top.v ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// UART core top level. ////
+//// ////
+//// Known problems (limits): ////
+//// Note that transmitter and receiver instances are inside ////
+//// the uart_regs.v file. ////
+//// ////
+//// To Do: ////
+//// Nothing so far. ////
+//// ////
+//// Author(s): ////
+//// - gorban@opencores.org ////
+//// - Jacob Gorban ////
+//// - Igor Mohor (igorm@opencores.org) ////
+//// ////
+//// Created: 2001/05/12 ////
+//// Last Updated: 2001/05/17 ////
+//// (See log for the revision history) ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+// Revision 1.18 2002/07/22 23:02:23 gorban
+// Bug Fixes:
+// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
+// Problem reported by Kenny.Tung.
+// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
+//
+// Improvements:
+// * Made FIFO's as general inferrable memory where possible.
+// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
+// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
+//
+// * Added optional baudrate output (baud_o).
+// This is identical to BAUDOUT* signal on 16550 chip.
+// It outputs 16xbit_clock_rate - the divided clock.
+// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
+//
+// Revision 1.17 2001/12/19 08:40:03 mohor
+// Warnings fixed (unused signals removed).
+//
+// Revision 1.16 2001/12/06 14:51:04 gorban
+// Bug in LSR[0] is fixed.
+// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers.
+//
+// Revision 1.15 2001/12/03 21:44:29 gorban
+// Updated specification documentation.
+// Added full 32-bit data bus interface, now as default.
+// Address is 5-bit wide in 32-bit data bus mode.
+// Added wb_sel_i input to the core. It's used in the 32-bit mode.
+// Added debug interface with two 32-bit read-only registers in 32-bit mode.
+// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
+// My small test bench is modified to work with 32-bit mode.
+//
+// Revision 1.14 2001/11/07 17:51:52 gorban
+// Heavily rewritten interrupt and LSR subsystems.
+// Many bugs hopefully squashed.
+//
+// Revision 1.13 2001/10/20 09:58:40 gorban
+// Small synopsis fixes
+//
+// Revision 1.12 2001/08/25 15:46:19 gorban
+// Modified port names again
+//
+// Revision 1.11 2001/08/24 21:01:12 mohor
+// Things connected to parity changed.
+// Clock devider changed.
+//
+// Revision 1.10 2001/08/23 16:05:05 mohor
+// Stop bit bug fixed.
+// Parity bug fixed.
+// WISHBONE read cycle bug fixed,
+// OE indicator (Overrun Error) bug fixed.
+// PE indicator (Parity Error) bug fixed.
+// Register read bug fixed.
+//
+// Revision 1.4 2001/05/31 20:08:01 gorban
+// FIFO changes and other corrections.
+//
+// Revision 1.3 2001/05/21 19:12:02 gorban
+// Corrected some Linter messages.
+//
+// Revision 1.2 2001/05/17 18:34:18 gorban
+// First 'stable' release. Should be sythesizable now. Also added new header.
+//
+// Revision 1.0 2001-05-17 21:27:12+02 jacob
+// Initial revision
+//
+//
+
+`include "uart_defines.v"
+
+module uart_top (
+ wb_clk_i,
+
+ // Wishbone signals
+ wb_rst_i, wb_adr_i, wb_dat_i, wb_dat_o, wb_we_i, wb_stb_i, wb_cyc_i, wb_ack_o, wb_sel_i,
+ int_o, // interrupt request
+
+ // UART signals
+ // serial input/output
+ stx_pad_o, srx_pad_i,
+
+ // modem signals
+ rts_pad_o, cts_pad_i, dtr_pad_o, dsr_pad_i, ri_pad_i, dcd_pad_i
+`ifdef UART_HAS_BAUDRATE_OUTPUT
+ , baud_o
+`endif
+ );
+parameter SIM = 0;
+parameter debug = 0;
+
+input wb_clk_i;
+
+// WISHBONE interface
+input wb_rst_i;
+input [2:0] wb_adr_i;
+input [7:0] wb_dat_i;
+output [7:0] wb_dat_o;
+input wb_we_i;
+input wb_stb_i;
+input wb_cyc_i;
+input [3:0] wb_sel_i;
+output wb_ack_o;
+output int_o;
+
+// UART signals
+input srx_pad_i;
+output stx_pad_o;
+output rts_pad_o;
+input cts_pad_i;
+output dtr_pad_o;
+input dsr_pad_i;
+input ri_pad_i;
+input dcd_pad_i;
+
+// optional baudrate output
+`ifdef UART_HAS_BAUDRATE_OUTPUT
+output baud_o;
+`endif
+
+
+wire stx_pad_o;
+wire rts_pad_o;
+wire dtr_pad_o;
+
+wire [2:0] wb_adr_i;
+wire [7:0] wb_dat_i;
+wire [7:0] wb_dat_o;
+
+wire [7:0] wb_dat8_i; // 8-bit internal data input
+wire [7:0] wb_dat8_o; // 8-bit internal data output
+wire [31:0] wb_dat32_o; // debug interface 32-bit output
+wire [3:0] wb_sel_i; // WISHBONE select signal
+wire [2:0] wb_adr_int;
+wire we_o; // Write enable for registers
+wire re_o; // Read enable for registers
+//
+// MODULE INSTANCES
+//
+
+//// WISHBONE interface module
+uart_wb wb_interface(
+ .clk( wb_clk_i ),
+ .wb_rst_i( wb_rst_i ),
+ .wb_dat_i(wb_dat_i),
+ .wb_dat_o(wb_dat_o),
+ .wb_dat8_i(wb_dat8_i),
+ .wb_dat8_o(wb_dat8_o),
+ .wb_dat32_o(32'b0),
+ .wb_sel_i(4'b0),
+ .wb_we_i( wb_we_i ),
+ .wb_stb_i( wb_stb_i ),
+ .wb_cyc_i( wb_cyc_i ),
+ .wb_ack_o( wb_ack_o ),
+ .wb_adr_i(wb_adr_i),
+ .wb_adr_int(wb_adr_int),
+ .we_o( we_o ),
+ .re_o(re_o)
+ );
+
+// Registers
+uart_regs #(.SIM (SIM)) regs(
+ .clk( wb_clk_i ),
+ .wb_rst_i( wb_rst_i ),
+ .wb_addr_i( wb_adr_int ),
+ .wb_dat_i( wb_dat8_i ),
+ .wb_dat_o( wb_dat8_o ),
+ .wb_we_i( we_o ),
+ .wb_re_i(re_o),
+ .modem_inputs( {cts_pad_i, dsr_pad_i,
+ ri_pad_i, dcd_pad_i} ),
+ .stx_pad_o( stx_pad_o ),
+ .srx_pad_i( srx_pad_i ),
+ .rts_pad_o( rts_pad_o ),
+ .dtr_pad_o( dtr_pad_o ),
+ .int_o( int_o )
+`ifdef UART_HAS_BAUDRATE_OUTPUT
+ , .baud_o(baud_o)
+`endif
+
+);
+
+initial
+begin
+ if(debug) begin
+ `ifdef UART_HAS_BAUDRATE_OUTPUT
+ $display("(%m) UART INFO: Has baudrate output\n");
+ `else
+ $display("(%m) UART INFO: Doesn't have baudrate output\n");
+ `endif
+ end
+end
+
+endmodule
+
+
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// uart_transmitter.v ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// UART core transmitter logic ////
+//// ////
+//// Known problems (limits): ////
+//// None known ////
+//// ////
+//// To Do: ////
+//// Thourough testing. ////
+//// ////
+//// Author(s): ////
+//// - gorban@opencores.org ////
+//// - Jacob Gorban ////
+//// - Igor Mohor (igorm@opencores.org) ////
+//// ////
+//// Created: 2001/05/12 ////
+//// Last Updated: 2001/05/17 ////
+//// (See log for the revision history) ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+// Revision 1.18 2002/07/22 23:02:23 gorban
+// Bug Fixes:
+// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
+// Problem reported by Kenny.Tung.
+// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
+//
+// Improvements:
+// * Made FIFO's as general inferrable memory where possible.
+// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
+// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
+//
+// * Added optional baudrate output (baud_o).
+// This is identical to BAUDOUT* signal on 16550 chip.
+// It outputs 16xbit_clock_rate - the divided clock.
+// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
+//
+// Revision 1.16 2002/01/08 11:29:40 mohor
+// tf_pop was too wide. Now it is only 1 clk cycle width.
+//
+// Revision 1.15 2001/12/17 14:46:48 mohor
+// overrun signal was moved to separate block because many sequential lsr
+// reads were preventing data from being written to rx fifo.
+// underrun signal was not used and was removed from the project.
+//
+// Revision 1.14 2001/12/03 21:44:29 gorban
+// Updated specification documentation.
+// Added full 32-bit data bus interface, now as default.
+// Address is 5-bit wide in 32-bit data bus mode.
+// Added wb_sel_i input to the core. It's used in the 32-bit mode.
+// Added debug interface with two 32-bit read-only registers in 32-bit mode.
+// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
+// My small test bench is modified to work with 32-bit mode.
+//
+// Revision 1.13 2001/11/08 14:54:23 mohor
+// Comments in Slovene language deleted, few small fixes for better work of
+// old tools. IRQs need to be fix.
+//
+// Revision 1.12 2001/11/07 17:51:52 gorban
+// Heavily rewritten interrupt and LSR subsystems.
+// Many bugs hopefully squashed.
+//
+// Revision 1.11 2001/10/29 17:00:46 gorban
+// fixed parity sending and tx_fifo resets over- and underrun
+//
+// Revision 1.10 2001/10/20 09:58:40 gorban
+// Small synopsis fixes
+//
+// Revision 1.9 2001/08/24 21:01:12 mohor
+// Things connected to parity changed.
+// Clock devider changed.
+//
+// Revision 1.8 2001/08/23 16:05:05 mohor
+// Stop bit bug fixed.
+// Parity bug fixed.
+// WISHBONE read cycle bug fixed,
+// OE indicator (Overrun Error) bug fixed.
+// PE indicator (Parity Error) bug fixed.
+// Register read bug fixed.
+//
+// Revision 1.6 2001/06/23 11:21:48 gorban
+// DL made 16-bit long. Fixed transmission/reception bugs.
+//
+// Revision 1.5 2001/06/02 14:28:14 gorban
+// Fixed receiver and transmitter. Major bug fixed.
+//
+// Revision 1.4 2001/05/31 20:08:01 gorban
+// FIFO changes and other corrections.
+//
+// Revision 1.3 2001/05/27 17:37:49 gorban
+// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
+//
+// Revision 1.2 2001/05/21 19:12:02 gorban
+// Corrected some Linter messages.
+//
+// Revision 1.1 2001/05/17 18:34:18 gorban
+// First 'stable' release. Should be sythesizable now. Also added new header.
+//
+// Revision 1.0 2001-05-17 21:27:12+02 jacob
+// Initial revision
+//
+//
+
+`include "uart_defines.v"
+
+module uart_transmitter
+#(parameter SIM = 0)
+ (clk, wb_rst_i, lcr, tf_push, wb_dat_i, enable, stx_pad_o, tstate, tf_count, tx_reset, lsr_mask);
+
+input clk;
+input wb_rst_i;
+input [7:0] lcr;
+input tf_push;
+input [7:0] wb_dat_i;
+input enable;
+input tx_reset;
+input lsr_mask; //reset of fifo
+output stx_pad_o;
+output [2:0] tstate;
+output [`UART_FIFO_COUNTER_W-1:0] tf_count;
+
+reg [2:0] tstate;
+reg [4:0] counter;
+reg [2:0] bit_counter; // counts the bits to be sent
+reg [6:0] shift_out; // output shift register
+reg stx_o_tmp;
+reg parity_xor; // parity of the word
+reg tf_pop;
+reg bit_out;
+
+// TX FIFO instance
+//
+// Transmitter FIFO signals
+wire [`UART_FIFO_WIDTH-1:0] tf_data_in;
+wire [`UART_FIFO_WIDTH-1:0] tf_data_out;
+wire tf_push;
+wire tf_overrun;
+wire [`UART_FIFO_COUNTER_W-1:0] tf_count;
+
+assign tf_data_in = wb_dat_i;
+
+uart_tfifo fifo_tx( // error bit signal is not used in transmitter FIFO
+ .clk( clk ),
+ .wb_rst_i( wb_rst_i ),
+ .data_in( tf_data_in ),
+ .data_out( tf_data_out ),
+ .push( tf_push ),
+ .pop( tf_pop ),
+ .overrun( tf_overrun ),
+ .count( tf_count ),
+ .fifo_reset( tx_reset ),
+ .reset_status(lsr_mask)
+);
+
+// TRANSMITTER FINAL STATE MACHINE
+
+localparam s_idle = 3'd0;
+localparam s_send_start = 3'd1;
+localparam s_send_byte = 3'd2;
+localparam s_send_parity = 3'd3;
+localparam s_send_stop = 3'd4;
+localparam s_pop_byte = 3'd5;
+
+always @(posedge clk or posedge wb_rst_i)
+begin
+ if (wb_rst_i)
+ begin
+ tstate <= s_idle;
+ stx_o_tmp <= 1'b1;
+ counter <= 5'b0;
+ shift_out <= 7'b0;
+ bit_out <= 1'b0;
+ parity_xor <= 1'b0;
+ tf_pop <= 1'b0;
+ bit_counter <= 3'b0;
+ end
+ else
+ if (enable | SIM)
+ begin
+ case (tstate)
+ s_idle : if (~|tf_count) // if tf_count==0
+ begin
+ tstate <= s_idle;
+ stx_o_tmp <= 1'b1;
+ end
+ else
+ begin
+ tf_pop <= 1'b0;
+ stx_o_tmp <= 1'b1;
+ tstate <= s_pop_byte;
+ end
+ s_pop_byte : begin
+ tf_pop <= 1'b1;
+ case (lcr[/*`UART_LC_BITS*/1:0]) // number of bits in a word
+ 2'b00 : begin
+ bit_counter <= 3'b100;
+ parity_xor <= ^tf_data_out[4:0];
+ end
+ 2'b01 : begin
+ bit_counter <= 3'b101;
+ parity_xor <= ^tf_data_out[5:0];
+ end
+ 2'b10 : begin
+ bit_counter <= 3'b110;
+ parity_xor <= ^tf_data_out[6:0];
+ end
+ 2'b11 : begin
+ bit_counter <= 3'b111;
+ parity_xor <= ^tf_data_out[7:0];
+ end
+ endcase
+ {shift_out[6:0], bit_out} <= tf_data_out;
+ tstate <= s_send_start;
+ end
+ s_send_start : begin
+ tf_pop <= 1'b0;
+ if (~|counter)
+ counter <= 5'b01111;
+ else
+ if (counter == 5'b00001)
+ begin
+ counter <= 0;
+ tstate <= s_send_byte;
+ end
+ else
+ counter <= counter - 5'd1;
+ stx_o_tmp <= 1'b0;
+ if (SIM) begin
+ tstate <= s_idle;
+ $write("%c", tf_data_out);
+ $fflush(32'h80000001);
+ end
+ end
+ s_send_byte : begin
+ if (~|counter)
+ counter <= 5'b01111;
+ else
+ if (counter == 5'b00001)
+ begin
+ if (bit_counter > 3'b0)
+ begin
+ bit_counter <= bit_counter - 3'd1;
+ {shift_out[5:0],bit_out } <= {shift_out[6:1], shift_out[0]};
+ tstate <= s_send_byte;
+ end
+ else // end of byte
+ if (~lcr[`UART_LC_PE])
+ begin
+ tstate <= s_send_stop;
+ end
+ else
+ begin
+ case ({lcr[`UART_LC_EP],lcr[`UART_LC_SP]})
+ 2'b00: bit_out <= ~parity_xor;
+ 2'b01: bit_out <= 1'b1;
+ 2'b10: bit_out <= parity_xor;
+ 2'b11: bit_out <= 1'b0;
+ endcase
+ tstate <= s_send_parity;
+ end
+ counter <= 0;
+ end
+ else
+ counter <= counter - 5'd1;
+ stx_o_tmp <= bit_out; // set output pin
+ end
+ s_send_parity : begin
+ if (~|counter)
+ counter <= 5'b01111;
+ else
+ if (counter == 5'b00001)
+ begin
+ counter <= 5'd0;
+ tstate <= s_send_stop;
+ end
+ else
+ counter <= counter - 5'd1;
+ stx_o_tmp <= bit_out;
+ end
+ s_send_stop : begin
+ if (~|counter)
+ begin
+ casez ({lcr[`UART_LC_SB],lcr[`UART_LC_BITS]})
+ 3'b0??: counter <= 5'b01101; // 1 stop bit ok igor
+ 3'b100: counter <= 5'b10101; // 1.5 stop bit
+ default: counter <= 5'b11101; // 2 stop bits
+ endcase
+ end
+ else
+ if (counter == 5'b00001)
+ begin
+ counter <= 0;
+ tstate <= s_idle;
+ end
+ else
+ counter <= counter - 5'd1;
+ stx_o_tmp <= 1'b1;
+ end
+
+ default : // should never get here
+ tstate <= s_idle;
+ endcase
+ end // end if enable
+ else
+ tf_pop <= 1'b0; // tf_pop must be 1 cycle width
+end // transmitter logic
+
+assign stx_pad_o = lcr[`UART_LC_BC] ? 1'b0 : stx_o_tmp; // Break condition
+
+endmodule
--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// uart_wb.v ////
+//// ////
+//// ////
+//// This file is part of the "UART 16550 compatible" project ////
+//// http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Documentation related to this project: ////
+//// - http://www.opencores.org/cores/uart16550/ ////
+//// ////
+//// Projects compatibility: ////
+//// - WISHBONE ////
+//// RS232 Protocol ////
+//// 16550D uart (mostly supported) ////
+//// ////
+//// Overview (main Features): ////
+//// UART core WISHBONE interface. ////
+//// ////
+//// Known problems (limits): ////
+//// Inserts one wait state on all transfers. ////
+//// Note affected signals and the way they are affected. ////
+//// ////
+//// To Do: ////
+//// Nothing. ////
+//// ////
+//// Author(s): ////
+//// - gorban@opencores.org ////
+//// - Jacob Gorban ////
+//// - Igor Mohor (igorm@opencores.org) ////
+//// ////
+//// Created: 2001/05/12 ////
+//// Last Updated: 2001/05/17 ////
+//// (See log for the revision history) ////
+//// ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// Copyright (C) 2000, 2001 Authors ////
+//// ////
+//// This source file may be used and distributed without ////
+//// restriction provided that this copyright statement is not ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer. ////
+//// ////
+//// This source file is free software; you can redistribute it ////
+//// and/or modify it under the terms of the GNU Lesser General ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any ////
+//// later version. ////
+//// ////
+//// This source is distributed in the hope that it will be ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
+//// PURPOSE. See the GNU Lesser General Public License for more ////
+//// details. ////
+//// ////
+//// You should have received a copy of the GNU Lesser General ////
+//// Public License along with this source; if not, download it ////
+//// from http://www.opencores.org/lgpl.shtml ////
+//// ////
+//////////////////////////////////////////////////////////////////////
+//
+// CVS Revision History
+//
+// $Log: not supported by cvs2svn $
+// Revision 1.16 2002/07/29 21:16:18 gorban
+// The uart_defines.v file is included again in sources.
+//
+// Revision 1.15 2002/07/22 23:02:23 gorban
+// Bug Fixes:
+// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
+// Problem reported by Kenny.Tung.
+// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
+//
+// Improvements:
+// * Made FIFO's as general inferrable memory where possible.
+// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
+// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
+//
+// * Added optional baudrate output (baud_o).
+// This is identical to BAUDOUT* signal on 16550 chip.
+// It outputs 16xbit_clock_rate - the divided clock.
+// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
+//
+// Revision 1.12 2001/12/19 08:03:34 mohor
+// Warnings cleared.
+//
+// Revision 1.11 2001/12/06 14:51:04 gorban
+// Bug in LSR[0] is fixed.
+// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers.
+//
+// Revision 1.10 2001/12/03 21:44:29 gorban
+// Updated specification documentation.
+// Added full 32-bit data bus interface, now as default.
+// Address is 5-bit wide in 32-bit data bus mode.
+// Added wb_sel_i input to the core. It's used in the 32-bit mode.
+// Added debug interface with two 32-bit read-only registers in 32-bit mode.
+// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
+// My small test bench is modified to work with 32-bit mode.
+//
+// Revision 1.9 2001/10/20 09:58:40 gorban
+// Small synopsis fixes
+//
+// Revision 1.8 2001/08/24 21:01:12 mohor
+// Things connected to parity changed.
+// Clock devider changed.
+//
+// Revision 1.7 2001/08/23 16:05:05 mohor
+// Stop bit bug fixed.
+// Parity bug fixed.
+// WISHBONE read cycle bug fixed,
+// OE indicator (Overrun Error) bug fixed.
+// PE indicator (Parity Error) bug fixed.
+// Register read bug fixed.
+//
+// Revision 1.4 2001/05/31 20:08:01 gorban
+// FIFO changes and other corrections.
+//
+// Revision 1.3 2001/05/21 19:12:01 gorban
+// Corrected some Linter messages.
+//
+// Revision 1.2 2001/05/17 18:34:18 gorban
+// First 'stable' release. Should be sythesizable now. Also added new header.
+//
+// Revision 1.0 2001-05-17 21:27:13+02 jacob
+// Initial revision
+//
+//
+
+// UART core WISHBONE interface
+//
+// Author: Jacob Gorban (jacob.gorban@flextronicssemi.com)
+// Company: Flextronics Semiconductor
+//
+
+`include "uart_defines.v"
+
+module uart_wb (clk, wb_rst_i,
+ wb_we_i, wb_stb_i, wb_cyc_i, wb_ack_o, wb_adr_i,
+ wb_adr_int, wb_dat_i, wb_dat_o, wb_dat8_i, wb_dat8_o, wb_dat32_o, wb_sel_i,
+ we_o, re_o // Write and read enable output for the core
+);
+
+input clk;
+
+// WISHBONE interface
+input wb_rst_i;
+input wb_we_i;
+input wb_stb_i;
+input wb_cyc_i;
+input [3:0] wb_sel_i;
+input [2:0] wb_adr_i; //WISHBONE address line
+
+input [7:0] wb_dat_i; //input WISHBONE bus
+output [7:0] wb_dat_o;
+reg [7:0] wb_dat_o;
+wire [7:0] wb_dat_i;
+reg [7:0] wb_dat_is;
+
+output [2:0] wb_adr_int; // internal signal for address bus
+input [7:0] wb_dat8_o; // internal 8 bit output to be put into wb_dat_o
+output [7:0] wb_dat8_i;
+input [31:0] wb_dat32_o; // 32 bit data output (for debug interface)
+output wb_ack_o;
+output we_o;
+output re_o;
+
+wire we_o;
+reg wb_ack_o;
+reg [7:0] wb_dat8_i;
+wire [7:0] wb_dat8_o;
+wire [2:0] wb_adr_int; // internal signal for address bus
+reg [2:0] wb_adr_is;
+reg wb_we_is;
+reg wb_cyc_is;
+reg wb_stb_is;
+wire [3:0] wb_sel_i;
+reg wre ;// timing control signal for write or read enable
+
+// wb_ack_o FSM
+reg [1:0] wbstate;
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) begin
+ wb_ack_o <= 1'b0;
+ wbstate <= 0;
+ wre <= 1'b1;
+ end else
+ case (wbstate)
+ 0: begin
+ if (wb_stb_is & wb_cyc_is) begin
+ wre <= 0;
+ wbstate <= 1;
+ wb_ack_o <= 1;
+ end else begin
+ wre <= 1;
+ wb_ack_o <= 0;
+ end
+ end
+ 1: begin
+ wb_ack_o <= 0;
+ wbstate <= 2;
+ wre <= 0;
+ end
+ 2: begin
+ wb_ack_o <= 0;
+ wbstate <= 3;
+ wre <= 0;
+ end
+ 3: begin
+ wb_ack_o <= 0;
+ wbstate <= 0;
+ wre <= 1;
+ end
+ endcase
+
+assign we_o = wb_we_is & wb_stb_is & wb_cyc_is & wre ; //WE for registers
+assign re_o = ~wb_we_is & wb_stb_is & wb_cyc_is & wre ; //RE for registers
+
+// Sample input signals
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i) begin
+ wb_adr_is <= 0;
+ wb_we_is <= 0;
+ wb_cyc_is <= 0;
+ wb_stb_is <= 0;
+ wb_dat_is <= 0;
+ end else begin
+ wb_adr_is <= wb_adr_i;
+ wb_we_is <= wb_we_i;
+ wb_cyc_is <= wb_cyc_i;
+ wb_stb_is <= wb_stb_i;
+ wb_dat_is <= wb_dat_i;
+ end
+
+always @(posedge clk or posedge wb_rst_i)
+ if (wb_rst_i)
+ wb_dat_o <= 0;
+ else
+ wb_dat_o <= wb_dat8_o;
+
+always @(wb_dat_is)
+ wb_dat8_i = wb_dat_is;
+
+assign wb_adr_int = wb_adr_is;
+
+
+endmodule
+
+
+
+
+
+
+
+
+
+
projects / microwatt.git / commitdiff