From 46bdbc5dbdccd15412749dd5e58adc16e1ad7bbb Mon Sep 17 00:00:00 2001
From: oharboe <oharboe@b42882b7-edfa-0310-969c-e2dbd0fdcd60>
Date: Wed, 18 Jun 2008 13:50:04 +0000
Subject: 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
---
src/jtag/presto.c | 196 +++++++++++++++++++++++++++++++++---------------------
1 file changed, 120 insertions(+), 76 deletions(-)
diff --git a/src/jtag/presto.c b/src/jtag/presto.c
index 3fd0ee12..21f80f00 100644
--- 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;
}
--
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