jtag.h

   1 /*
   2  * Code for interacting with the FPGA via JTAG.
   3  * This file is part of LUNA.
   4  *
   5  * This JTAG driver is intended to be as simple as possible in order to facilitate
   6  * configuration and debugging of the attached FPGA. It is not intended to be a general-
   7  * purpose JTAG link.
   8  */
   9
  10 #ifndef __JTAG_H__
  11 #define __JTAG_H__
  12
  13 typedef enum e_TAPState
  14 {
  15         STATE_TEST_LOGIC_RESET =  0,
  16         STATE_RUN_TEST_IDLE    =  1,
  17         STATE_SELECT_DR_SCAN   =  2,
  18         STATE_CAPTURE_DR       =  3,
  19         STATE_SHIFT_DR         =  4,
  20         STATE_EXIT1_DR         =  5,
  21         STATE_PAUSE_DR         =  6,
  22         STATE_EXIT2_DR         =  7,
  23         STATE_UPDATE_DR        =  8,
  24         STATE_SELECT_IR_SCAN   =  9,
  25         STATE_CAPTURE_IR       = 10,
  26         STATE_SHIFT_IR         = 11,
  27         STATE_EXIT1_IR         = 12,
  28         STATE_PAUSE_IR         = 13,
  29         STATE_EXIT2_IR         = 14,
  30         STATE_UPDATE_IR        = 15
  31 } jtag_tap_state_t;
  32
  33
  34 /**
  35  * Performs the start-of-day tasks necessary to talk JTAG to our FPGA.
  36  */
  37 void jtag_init(void);
  38
  39
  40 /**
  41  * De-inits the JTAG connection, so the JTAG chain. is no longer driven.
  42  */
  43 void jtag_deinit(void);
  44
  45
  46 /**
  47  * Moves to a given JTAG state.
  48  */
  49 void jtag_goto_state(int state);
  50
  51
  52 /**
  53  * Performs a raw TAP scan.
  54  */
  55 void jtag_tap_shift(
  56         uint8_t *input_data,
  57         uint8_t *output_data,
  58         uint32_t data_bits,
  59         bool must_end);
  60
  61
  62 void jtag_wait_time(uint32_t microseconds);
  63
  64 void jtag_go_to_state(unsigned state);
  65
  66 uint8_t jtag_current_state(void);
  67
  68 #endif