Pavel Chromy:

- lower jtag speeds (higher divisor) was used, TDI was not changed on falling TCK edge as it should
- reset signal was release upon any TMS transition, making it impossible to use reset halt
- added khz() and speed_div() functions

git-svn-id: svn://svn.berlios.de/openocd/trunk@716 b42882b7-edfa-0310-969c-e2dbd0fdcd60

diff --git a/src/jtag/presto.c b/src/jtag/presto.c
index 3fd0ee1219f1069fc9d6c7cf38270ee8d92aca76..21f80f00a1d90fe31198d872429122379f1d4b33 100644 (file)
--- a/src/jtag/presto.c
+++ b/src/jtag/presto.c
@@ -51,6 +51,8 @@
 
 
 int presto_jtag_speed(int speed);
+int presto_jtag_khz(int khz, int *jtag_speed);
+int presto_jtag_speed_div(int speed, int *khz);
 int presto_jtag_register_commands(struct command_context_s *cmd_ctx);
 int presto_jtag_init(void);
 int presto_jtag_quit(void);
@@ -60,6 +62,8 @@ jtag_interface_t presto_interface =
        .name = "presto",
        .execute_queue = bitq_execute_queue,
        .speed = presto_jtag_speed,
+       .khz = presto_jtag_khz,
+       .speed_div = presto_jtag_speed_div,
        .register_commands = presto_jtag_register_commands,
        .init = presto_jtag_init,
        .quit = presto_jtag_quit,
@@ -121,10 +125,13 @@ typedef struct presto_s
 
        int jtag_tms; /* last tms state */
        int jtag_tck; /* last tck state */
+       int jtag_rst; /* last trst state */
 
        int jtag_tdi_data;
        int jtag_tdi_count;
 
+       int jtag_speed;
+       
 } presto_t;
 
 presto_t presto_state;
@@ -422,9 +429,12 @@ int presto_open(char *req_serial)
 
        presto->jtag_tms=0;
        presto->jtag_tck=0;
+       presto->jtag_rst=0;
        presto->jtag_tdi_data=0;
        presto->jtag_tdi_count=0;
 
+       presto->jtag_speed=0;
+       
 #if BUILD_PRESTO_FTD2XX == 1
        return presto_open_ftd2xx(req_serial);
 #elif BUILD_PRESTO_LIBFTDI == 1
@@ -567,59 +577,83 @@ int presto_getbyte(void)
 /* -------------------------------------------------------------------------- */
 
 
+int presto_tdi_flush(void)
+{
+       if (presto->jtag_tdi_count == 0)
+               return 0;
+
+       if (presto->jtag_tck == 0)
+       {
+               LOG_ERROR("BUG: unexpected TAP condition, TCK low");
+               return -1;
+       }
+
+       presto->jtag_tdi_data |= (presto->jtag_tdi_count - 1) << 4;
+       presto_sendbyte(presto->jtag_tdi_data);
+       presto->jtag_tdi_count = 0;
+       presto->jtag_tdi_data = 0;
+       
+       return 0;
+}
+
+
+int presto_tck_idle(void)
+{
+       if (presto->jtag_tck == 1)
+       {
+               presto_sendbyte(0xCA);
+               presto->jtag_tck = 0;
+       }
+       
+       return 0;
+}
+
+
+/* -------------------------------------------------------------------------- */
+
+
 int presto_bitq_out(int tms, int tdi, int tdo_req)
 {
-       unsigned char cmdparam;
+       int i;
+       unsigned char cmd;
 
        if (presto->jtag_tck == 0)
        {
-               presto_sendbyte(0xA4); /* jtag activity */
-               presto->jtag_tck = 1; /* clock remains high after the function returns */
-               /* do just a single tick first, accelerated shifting needs TCK=1 */
+               presto_sendbyte(0xA4); /* LED idicator - JTAG active */
        }
-       else if (!tdo_req && tms == presto->jtag_tms)
+       else if (presto->jtag_speed == 0 && !tdo_req && tms == presto->jtag_tms)
        {
-               if (presto->jtag_tdi_count == 0)
-                       presto->jtag_tdi_data = (tdi != 0);
-               else
-                       presto->jtag_tdi_data |= (tdi != 0) << presto->jtag_tdi_count;
+               presto->jtag_tdi_data |= (tdi != 0) << presto->jtag_tdi_count;
 
                if (++presto->jtag_tdi_count == 4)
-               {
-                       presto->jtag_tdi_data |= (presto->jtag_tdi_count - 1) << 4;
-                       presto_sendbyte(presto->jtag_tdi_data);
-                       presto->jtag_tdi_count = 0;
-               }
-               return 0;
-       }
+                       presto_tdi_flush();
 
-       if (presto->jtag_tdi_count)
-       {
-               presto->jtag_tdi_data |= (presto->jtag_tdi_count - 1) << 4;
-               presto_sendbyte(presto->jtag_tdi_data);
-               presto->jtag_tdi_count = 0;
+               return 0;
        }
 
-       if (tdi)
-               cmdparam = 0x0B;
-       else
-               cmdparam = 0x0A;
+       presto_tdi_flush();
 
-       presto_sendbyte( 0xC0 | cmdparam);
+       cmd = tdi ? 0xCB : 0xCA;
+       presto_sendbyte(cmd);
 
        if (tms != presto->jtag_tms)
        {
-               if (tms)
-                       presto_sendbyte(0xEC);
-               else
-                       presto_sendbyte(0xE8);
+               presto_sendbyte((tms ? 0xEC : 0xE8) | (presto->jtag_rst ? 0x02 : 0));
                presto->jtag_tms = tms;
        }
 
-       if (tdo_req)
-               presto_sendbyte(0xD4|cmdparam);
-       else
-               presto_sendbyte(0xC4|cmdparam);
+       /* delay with TCK low */
+       for (i=presto->jtag_speed; i>1; i--)
+               presto_sendbyte(cmd);
+
+       cmd |= 0x04;
+       presto_sendbyte(cmd | (tdo_req ? 0x10 : 0));
+
+       /* delay with TCK high */
+       for (i=presto->jtag_speed; i>1; i--)
+               presto_sendbyte(cmd);
+
+       presto->jtag_tck = 1;
 
        return 0;
 }
@@ -627,20 +661,10 @@ int presto_bitq_out(int tms, int tdi, int tdo_req)
 
 int presto_bitq_flush(void)
 {
-       if (presto->jtag_tdi_count)
-       {
-               presto->jtag_tdi_data |= (presto->jtag_tdi_count - 1) << 4;
-               presto_sendbyte(presto->jtag_tdi_data);
-               presto->jtag_tdi_count = 0;
-       }
-
-       if (presto->jtag_tck == 1) 
-       {
-               presto_sendbyte(0xCA);
-               presto->jtag_tck = 0;
-       }
+       presto_tdi_flush();
+       presto_tck_idle();
 
-       presto_sendbyte(0xA0);
+       presto_sendbyte(0xA0); /* LED idicator - JTAG idle */
 
        return presto_flush();
 }
@@ -667,11 +691,8 @@ int presto_bitq_sleep(unsigned long us)
 {
        long waits;
 
-       if (presto->jtag_tck == 1) 
-       {
-               presto_sendbyte(0xCA);
-               presto->jtag_tck = 0;
-       }
+       presto_tdi_flush();
+       presto_tck_idle();
 
        if (us > 100000)
        {
@@ -690,47 +711,70 @@ int presto_bitq_sleep(unsigned long us)
 
 int presto_bitq_reset(int trst, int srst)
 {
-       unsigned char cmd;
-
-       if (presto->jtag_tck == 1) 
-       {
-               presto_sendbyte(0xCA);
-               presto->jtag_tck = 0;
-       }
+       presto_tdi_flush();
+       presto_tck_idle();
 
-       cmd = 0xE8;
-       if (presto->jtag_tms)
-               cmd |= 0x04;
+       /* add a delay after possible TCK transition */
+       presto_sendbyte(0x80);
+       presto_sendbyte(0x80);
 
-       if (trst || srst)
-               cmd |= 0x02;
+       presto->jtag_rst = trst || srst;
+       presto_sendbyte((presto->jtag_rst ? 0xEA : 0xE8) | (presto->jtag_tms ? 0x04 : 0));
 
-       presto_sendbyte(cmd);
        return 0;
 }
 
 
 /* -------------------------------------------------------------------------- */
 
-char *presto_speed_text[4] =
+
+int presto_jtag_khz(int khz, int *jtag_speed)
 {
-       "3 MHz",
-       "1.5 MHz",
-       "750 kHz",
-       "93.75 kHz"
-};
+       if (khz < 0)
+       {
+               *jtag_speed=0;
+               return ERROR_INVALID_ARGUMENTS;
+       }
 
-int presto_jtag_speed(int speed)
+       if (khz >= 3000) *jtag_speed = 0;
+       else *jtag_speed = (1000+khz-1)/khz;
+       
+       return 0;
+}
+
+
+int presto_jtag_speed_div(int speed, int *khz)
 {
+       if ((speed < 0) || (speed > 1000))
+       {
+               *khz=0;
+               return ERROR_INVALID_ARGUMENTS;
+       }
+
+       if (speed == 0) *khz = 3000;
+       else *khz = 1000/speed;
+       
+       return 0;
+}
+
 
-       if ((speed < 0) || (speed > 3))
+int presto_jtag_speed(int speed)
+{
+       int khz;
+       
+       if (presto_jtag_speed_div(speed, &khz))
        {
-               LOG_INFO("valid speed values: 0 (3 MHz), 1 (1.5 MHz), 2 (750 kHz) and 3 (93.75 kHz)");
                return ERROR_INVALID_ARGUMENTS;
        }
 
-       LOG_INFO("setting speed to %d, max. TCK freq. is %s", speed, presto_speed_text[speed]);
-       return presto_sendbyte(0xA8 | speed);
+       presto->jtag_speed = speed;
+       
+       if (khz%1000 == 0)
+               LOG_INFO("setting speed to %d, max. TCK freq. is %d MHz", speed, khz/1000);
+       else
+               LOG_INFO("setting speed to %d, max. TCK freq. is %d kHz", speed, khz);
+       
+       return 0;
 }