shift out bytes instead of bits, when possible

[ecpprog.git] / ecpprog / jtag_tap.c

diff --git a/ecpprog/jtag_tap.c b/ecpprog/jtag_tap.c
index 44781f5b4fba97fadf519c69388b6ce2ff58a309..cda86fd5688fac503f32eb9622738c1ecfba2976 100644 (file)
--- a/ecpprog/jtag_tap.c
+++ b/ecpprog/jtag_tap.c
@@ -6,6 +6,7 @@
  */
 
 #include <ftdi.h>
+#include <string.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdbool.h>
@@ -145,7 +146,7 @@ extern struct ftdi_context mpsse_ftdic;
 
 static inline void jtag_pulse_clock_and_read_tdo(bool tms, bool tdi)
 {
-    *ptr++ = MC_DATA_TMS | MC_DATA_IN | MC_DATA_LSB | MC_DATA_BITS;
+    *ptr++ = MC_DATA_TMS | MC_DATA_IN | MC_DATA_LSB | MC_DATA_BITS | MC_DATA_OCN;
        *ptr++ =  0;        
     *ptr++ = (tdi ? 0x80 : 0) | (tms ? 0x01 : 0);
        rx_cnt++;
@@ -185,6 +186,34 @@ static void _jtag_tap_shift(
                output_data[i] = data[7+i*8];
 }
 
+
+static void jtag_shift_bytes(
+       uint8_t *input_data,
+       uint8_t *output_data,
+       uint32_t data_bits,
+       bool must_end)
+{
+
+       /* Sanity check */
+       if(data_bits % 8 != 0){
+               printf("Error %u is not a byte multiple\n", data_bits);
+       }
+       //printf("jtag_shift_bytes(0x%08x,0x%08x,%u,%s);\n",input_data, output_data, data_bits, must_end ? "true" : "false");
+       uint32_t byte_count = data_bits / 8;
+
+
+
+       data[0] = MC_DATA_OUT | MC_DATA_IN | MC_DATA_LSB | MC_DATA_OCN;
+       data[1] = (byte_count - 1); 
+       data[2] = (byte_count - 1) >> 8;        
+       memcpy(data + 3, input_data, byte_count);
+
+       mpsse_xfer(data, byte_count + 3, byte_count);
+
+       memcpy(output_data, data, byte_count);
+}
+
+
 #define MIN(a,b) (a < b) ? a : b
 
 void jtag_tap_shift(
@@ -193,19 +222,35 @@ void jtag_tap_shift(
        uint32_t data_bits,
        bool must_end)
 {
+       /* if 'must_end' the send last byte seperately 
+        * This way we toggle TMS on the last clock cycle */
+       if(must_end)
+               data_bits -= 8;
+       
        uint32_t data_bits_sent = 0;
-       while(data_bits_sent != data_bits){
-
-               uint32_t _data_bits = MIN(256, data_bits);
-               bool last = (data_bits_sent + _data_bits) == data_bits;
+       if(data_bits){
+               while(data_bits_sent != data_bits){
+
+                       uint32_t _data_bits = MIN(4096 + 2048 + 1024, data_bits - data_bits_sent);
+
+                       jtag_shift_bytes(
+                               input_data + data_bits_sent/8,
+                               output_data + data_bits_sent/8,
+                               _data_bits,
+                               false
+                       );
+                       data_bits_sent += _data_bits;
+               }
+       }
 
+       /* Send our last byte */
+       if(must_end){
                _jtag_tap_shift(
                        input_data + data_bits_sent/8,
                        output_data + data_bits_sent/8,
-                       _data_bits,
-                       last & must_end
+                       8,
+                       must_end
                );
-               data_bits_sent += _data_bits;
        }
 }