stuff

bsp/rp2040/m_isp/mehfet_hw.c

@@ -78,7 +78,10 @@ void mehfet_hw_tclk_burst(uint32_t ncyc) {
     sbw_tclk_burst(ncyc);
 }
 
-void mehfet_hw_reset_tap(void) {
+enum mehfet_resettap_status mehfet_hw_reset_tap(enum mehfet_resettap_flags flags) {
+    enum mehfet_resettap_status rv = 0;
+
+    if (flags & mehfet_rsttap_do_reset) {
         // TDI always 1
         // TMS=1,1,1,1,1,1    -- reset TAP state to initial
         // TMS=0              -- test-logic-reset to run-test/idle
@@ -90,6 +93,33 @@ void mehfet_hw_reset_tap(void) {
         sbw_tms_sequence(14, true, tms_seq);
     }
 
+    if (flags & mehfet_rsttap_fuse_do) {
+        // TDI always 1
+        // TMS=01010110 // same sequence as above, but without TAP reset
+        const uint8_t tms_seq = 0x6a;
+        sbw_tms_sequence(8, true, &tms_seq);
+    }
+
+    if (flags & mehfet_rsttap_fuse_read) {
+        for (size_t i = 0; i < 3; ++i) {
+            mehfet_hw_shift_ir(0x14); // CNTRL_SIG_CAPTURE
+            uint16_t dr = mehfet_hw_shift_dr16(0xaaaa);
+            if (dr == 0x5555) {
+                rv |= mehfet_rsttap_fuse_blown;
+                break;
+            }
+        }
+    }
+
+    if (flags & mehfet_rsttap_highspeed) {
+        sbw_set_freq(true, 350e3);
+    } else {
+        sbw_set_freq(false, 50e3);
+    }
+
+    return rv;
+}
+
 uint8_t mehfet_hw_shift_ir(uint8_t newir) {
     // 1100: run-test/idle -> select-dr-scan -> select-ir-scan -> capture-ir -> shift-ir
     const uint8_t tms_seqa = 0x03;

src/m_isp/_isp.c

@@ -286,12 +286,12 @@ static void my_hid_set_report_cb(uint8_t instance, uint8_t report_id,
 #if CFG_TUD_CDC > 0
 static void my_cdc_line_coding_cb(uint8_t itf, cdc_line_coding_t const* line_coding) {
     switch (itf) {
-/*#ifdef DBOARD_HAS_UART
+#ifdef DBOARD_HAS_UART
         case CDC_N_UART:
             cdc_uart_set_coding(line_coding->bit_rate, line_coding->stop_bits,
                     line_coding->parity, line_coding->data_bits);
             break;
-#endif*/
+#endif
 #ifdef USE_USBCDC_FOR_STDIO
         case CDC_N_STDIO:
             stdio_usb_line_coding_cb(line_coding);

src/m_isp/mehfet.c

@@ -366,10 +366,10 @@ void mehfet_task(void) {
 
     case mehfet_reset_tap:
         if (!(mehfet_hw_get_caps() & mehfet_cap_has_reset_tap)) write_resp(mehfet_nocaps, 0, NULL);
-        else if (cmdhdr.len != 0) write_resp_str(mehfet_badargs, "ResetTAP takes no parameters");
+        else if (cmdhdr.len != 1) write_resp_str(mehfet_badargs, "ResetTAP takes one parameter byte");
         else {
-            mehfet_hw_reset_tap();
+            uint8_t v = mehfet_hw_reset_tap(read_pl());
-            write_resp(mehfet_ok, 0, NULL);
+            write_resp(mehfet_ok, 1, &v);
         }
         break;
     case mehfet_irshift:

src/m_isp/mehfet.h

@@ -1,3 +1,4 @@
+// vim: set et:
 
 #ifndef M_ISP_MEHFET
 #define M_ISP_MEHFET
@@ -62,6 +63,17 @@ enum mehfet_conn {
     mehfet_conn_nrstmask = 0x80
 };
 
+enum mehfet_resettap_flags {
+    mehfet_rsttap_do_reset  = 1<<0, // reset TAP to run-test/idle state
+    mehfet_rsttap_fuse_do   = 1<<1, // perform fuse check procedure (TMS pulses) on target
+    mehfet_rsttap_fuse_read = 1<<2, // check whether the JTAG fuse has been blown
+    mehfet_rsttap_highspeed = 1<<3, // can move to high-speed transport afterwards
+                                    // (fuse check procedure is max 50 kHz)
+};
+enum mehfet_resettap_status {
+    mehfet_rsttap_fuse_blown = 0x80
+};
+
 // hw routines
 
 void mehfet_hw_init(void);
@@ -86,10 +98,17 @@ void mehfet_hw_tms_seq(uint32_t ncyc, bool tdilvl, const uint8_t* tms);
 void mehfet_hw_tclk_edge(bool newtclk);
 void mehfet_hw_tclk_burst(uint32_t ncyc);
 
-void mehfet_hw_reset_tap(void);
+enum mehfet_resettap_status mehfet_hw_reset_tap(enum mehfet_resettap_flags flags);
 uint8_t mehfet_hw_shift_ir(uint8_t newir);
 // drin is not const here, as the implementation may want to shuffle stuff around
 void mehfet_hw_shift_dr(uint32_t nbits, uint8_t* drin, uint8_t* drout);
+static inline uint16_t mehfet_hw_shift_dr16(uint16_t newdr) {
+    uint8_t drin[2], drout[2];
+    drin[0] = (uint8_t)newdr;
+    drin[1] = (uint8_t)(newdr >> 8);
+    mehfet_hw_shift_dr(16, drin, drout);
+    return drout[0] | ((uint16_t)drout[1] << 8);
+}
 
 #endif