Reset through AIRCR (#540) (#712)

In addition to asserting the NRST line, also request system reset through the Application Interrupt and Reset Control Register (AIRCR).
stlink-org · May 31, 2018 · 6db0fc2 · 6db0fc2
1 parent 6f74f4a
commit 6db0fc2
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Showing 3 changed files with 14 additions and 5 deletions.
diff --git a/include/stlink/reg.h b/include/stlink/reg.h
@@ -12,4 +12,9 @@
 #define STLINK_REG_DCRSR        0xe000edf4
 #define STLINK_REG_DCRDR        0xe000edf8
 
+/* Application Interrupt and Reset Control Register */
+#define STLINK_REG_AIRCR                0xe000ed0c
+#define STLINK_REG_AIRCR_VECTKEY        0x05fa0000
+#define STLINK_REG_AIRCR_SYSRESETREQ    0x00000004
+
 #endif /* STLINK_REG_H_ */
diff --git a/src/sg.c b/src/sg.c
@@ -535,6 +535,11 @@ int _stlink_sg_reset(stlink_t *sl) {
     if (stlink_q(sl))
         return -1;
 
+    // Reset through AIRCR so NRST does not need to be connected
+    if (stlink_write_debug32(sl, STLINK_REG_AIRCR,
+                STLINK_REG_AIRCR_VECTKEY | STLINK_REG_AIRCR_SYSRESETREQ))
+        return -1;
+
     stlink_stat(sl, "core reset");
     return 0;
 }

diff --git a/src/usb.c b/src/usb.c
@@ -368,10 +368,7 @@ int _stlink_usb_exit_dfu_mode(stlink_t* sl) {
     return 0;
 }
 
-/**
- * TODO - not convinced this does anything...
- * @param sl
- */
+
 int _stlink_usb_reset(stlink_t * sl) {
     struct stlink_libusb * const slu = sl->backend_data;
     unsigned char* const data = sl->q_buf;
@@ -389,7 +386,9 @@ int _stlink_usb_reset(stlink_t * sl) {
         return (int) size;
     }
 
-    return 0;
+    // Reset through AIRCR so NRST does not need to be connected
+    return stlink_write_debug32(sl, STLINK_REG_AIRCR,
+            STLINK_REG_AIRCR_VECTKEY | STLINK_REG_AIRCR_SYSRESETREQ);
 }