getting further. IR/DR shifting definitely works, TCLK handling probably broken

CMakeLists.txt

@@ -33,6 +33,7 @@ if(FAMILY STREQUAL "rp2040")
     ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
     ${CMAKE_CURRENT_SOURCE_DIR}/src/pio_sbw.c
     ${CMAKE_CURRENT_SOURCE_DIR}/src/tap.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/msp430dbg.c
   )
 
  # Example include

src/main.c

@@ -1,8 +1,3 @@
-/**
- * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
 
 #include <stdio.h>
 
@@ -12,6 +7,7 @@
 
 #include "pio_sbw.h"
 #include "tap.h"
+#include "msp430dbg.h"
 
 void printbuf(const uint8_t* buf, size_t size) {
     for (size_t i = 0; i < size; ++i)
@@ -26,11 +22,11 @@ int main() {
 
     stdio_init_all();
 
-    sbw_preinit();
+    /*sbw_preinit();
     printf("%s\n", "preinited");
 
     bool s = sbw_init();
-    printf("%s\n", s ? "inited" : "failure");
+    printf("%s\n", s ? "inited" : "failure");*/
 
     /*uint8_t tdi = 0x0f, tdo = 0;
     sbw_sequence(8, true, &tdi, &tdo);
@@ -53,12 +49,15 @@ int main() {
     sbw_tclk_burst(16);
     printf("done.\n");*/
 
-    sbw_tap_reset();
-    sbw_check_fuse();
+//    sbw_tap_reset();
+//    sbw_check_fuse();
+//
+//    uint8_t id = sbw_tap_shift_ir(0xff/*IR_BYPASS*/);
+//
+//    printf("JTAG ID=%02x\n", id);
 
-    uint8_t id = sbw_tap_shift_ir(0xff/*IR_BYPASS*/);
-
-    printf("JTAG ID=%02x\n", id);
+	uint32_t initv = msp430_device_get(200e3);
+	printf("init -> %08lx\n", initv);
 
     return 0;
 }

src/pio_sbw.c

@@ -1,8 +1,3 @@
-/**
- * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
 
 #include <hardware/clocks.h>
 #include <hardware/dma.h>
@@ -88,7 +83,12 @@ bool sbw_init(void) {
         return false;
     }
 
-    sbw_pio_init(PINOUT_SBW_PIO, sbw_piosm, sbw_offset, 200e3,
+    // need to start at 50 kHz: fuse check needs TMS cycles with a low phase
+    // of at least 5us. 50 kHz is below the required time (the actual maximum
+    // frequency would be around 80 kHz), but the exact frequency doesn't
+    // matter much as we'll switch to a higher one once the check has been
+    // completed
+    sbw_pio_init(PINOUT_SBW_PIO, sbw_piosm, sbw_offset, 50e3,
             PINOUT_SBW_TCK, PINOUT_SBW_TDIO);
 
     last_tdi = last_tms = 0xff;
@@ -133,6 +133,7 @@ static uint8_t bitswap(uint8_t in) {
 
 bool sbw_get_last_tms(void) { return last_tms; }
 bool sbw_get_last_tdi(void) { return last_tdi; }
+bool sbw_get_last_tclk(void) { return last_tclk; }
 
 void sbw_sequence(uint32_t ncyc, bool tms, const uint8_t* tdi, uint8_t* tdo) {
     if (ncyc == 0) return;

src/pio_sbw.h

@@ -26,6 +26,7 @@ void sbw_set_freq(bool tclk, float freq);
 
 bool sbw_get_last_tms(void);
 bool sbw_get_last_tdi(void);
+bool sbw_get_last_tclk(void);
 
 void sbw_sequence(uint32_t ncyc, bool tms, const uint8_t* tdi, uint8_t* tdo);
 void sbw_tms_sequence(uint32_t ncyc, bool tdi, const uint8_t* tms);

src/tap.c

@@ -1,4 +1,6 @@
 
+#include <stdio.h>
+
 #include "pio_sbw.h"
 
 #include "tap.h"
@@ -33,17 +35,25 @@ static uint8_t bitswap(uint8_t in) {
     return (lut[in&0xf] << 4) | lut[in>>4];
 }
 static inline uint16_t bitswap16(uint16_t in) {
+	//printf("bitswap in=%04x\n", in);
     return ((uint16_t)bitswap(in & 0xff) << 8) | bitswap(in >> 8);
 }
 
+// IR in = OK
+// IR out = OK
+// DR out = OK
+// DR in = BAD!
+
 uint16_t sbw_tap_shift_dr(uint16_t newdr) {
     // DR content is MSB-first instead of LSB-first (IR is the latter)
     // except the PIO already does bitswaps, so we need to do it for the IR instead
-    newdr = /*bitswap16(*/newdr/*)*/;
+    newdr = bitswap16(newdr);
 
     // 100: run-test/idle -> select-dr-scan -> capture-dr -> shift-dr
-    const uint8_t tms_seq = 0x01;
-    sbw_tms_sequence(3, true, &tms_seq);
+    const uint8_t tms_seqa = 0x01;
+    const uint8_t tms_seqb = 0x01 >> 1;
+    sbw_tms_sequence(1, sbw_get_last_tclk(), &tms_seqa);
+    sbw_tms_sequence(2, true, &tms_seqb);
 
     // 15 data bits with TMS=0
     // 1 data bit with TMS=1 (to exit1-dr)
@@ -55,18 +65,22 @@ uint16_t sbw_tap_shift_dr(uint16_t newdr) {
 
     // TMS=1 (to update-dr)
     // TMS=0 (to run-test/idle)
-    const uint8_t tms_seq_2 = 0x01;
-    sbw_tms_sequence(2, true, &tms_seq_2);
+    const uint8_t tms_seq_2a = 0x01;
+    const uint8_t tms_seq_2b = 0x01 >> 1;
+    sbw_tms_sequence(1, true, &tms_seq_2a);
+    sbw_tms_sequence(1, sbw_get_last_tclk(), &tms_seq_2b);
 
-    return /*bitswap16(*/res/*)*/;
+    return bitswap16(res);
 }
 
 uint8_t sbw_tap_shift_ir(uint8_t newir) {
-    newir = bitswap(newir);
+    newir = /*bitswap(*/newir/*)*/;
 
     // 1100: run-test/idle -> select-dr-scan -> select-ir-scan -> capture-ir -> shift-ir
-    const uint8_t tms_seq = 0x03;
-    sbw_tms_sequence(4, true, &tms_seq);
+    const uint8_t tms_seqa = 0x03;
+    const uint8_t tms_seqb = 0x03 >> 1;
+    sbw_tms_sequence(1, sbw_get_last_tclk(), &tms_seqa);
+    sbw_tms_sequence(3, true, &tms_seqb);
 
     // 7 data bits with TMS=0
     // 1 data bit with TMS=1 (to exit1-ir)
@@ -77,8 +91,10 @@ uint8_t sbw_tap_shift_ir(uint8_t newir) {
 
     // TMS=1 (to update-ir)
     // TMS=0 (to run-test/idle)
-    const uint8_t tms_seq_2 = 0x01;
-    sbw_tms_sequence(2, true, &tms_seq_2);
+    const uint8_t tms_seq_2a = 0x01;
+    const uint8_t tms_seq_2b = 0x01 >> 1;
+    sbw_tms_sequence(1, true, &tms_seq_2a);
+    sbw_tms_sequence(1, sbw_get_last_tclk(), &tms_seq_2b);
 
     return bitswap(res);
 }

src/tap.h

@@ -2,6 +2,8 @@
 #ifndef SBW_TAP_H_
 #define SBW_TAP_H_
 
+#include <stdint.h>
+
 // move to run-test/idle. typically this is done by sending a single TMS=0
 // cycle, but the MSP430 has an extra JTAG fuse check that needs to be done
 void sbw_tap_reset(void);