xvsf player fixes by Dick Hollenbeck <dick@softplc.com>

[openocd.git] / src / jtag / bitbang.c

diff --git a/src/jtag/bitbang.c b/src/jtag/bitbang.c
index e4191d1487e9a35a65767fee33ca5e084a7b8615..05416005e74351678a2038a9e49d4f5a04ccac31 100644 (file)
--- a/src/jtag/bitbang.c
+++ b/src/jtag/bitbang.c
@@ -38,6 +38,14 @@
 #include <unistd.h>
 
 
+/**
+ * Function bitbang_stableclocks
+ * issues a number of clock cycles while staying in a stable state.
+ * Because the TMS value required to stay in the RESET state is a 1, whereas
+ * the TMS value required to stay in any of the other stable states is a 0,
+ * this function checks the current stable state to decide on the value of TMS
+ * to use.
+ */
 static void bitbang_stableclocks(int num_cycles);
 
 
@@ -162,13 +170,14 @@ void bitbang_runtest(int num_cycles)
 
 static void bitbang_stableclocks(int num_cycles)
 {
+       int tms = (cur_state == TAP_RESET ? 1 : 0);
        int i;
 
        /* send num_cycles clocks onto the cable */
        for (i = 0; i < num_cycles; i++)
        {
-               bitbang_interface->write(1, 0, 0);
-               bitbang_interface->write(0, 0, 0);
+               bitbang_interface->write(1, tms, 0);
+               bitbang_interface->write(0, tms, 0);
        }
 }
 
@@ -293,6 +302,9 @@ int bitbang_execute_queue(void)
                                break;
 
                        case JTAG_STABLECLOCKS:
+                               /* this is only allowed while in a stable state.  A check for a stable
+                                * state was done in jtag_add_clocks()
+                                */
                                bitbang_stableclocks(cmd->cmd.stableclocks->num_cycles);
                                break;