From 5f9b74d0557ec577b45d7af18312bab58098c9d9 Mon Sep 17 00:00:00 2001
From: zwelch <zwelch@b42882b7-edfa-0310-969c-e2dbd0fdcd60>
Date: Tue, 16 Jun 2009 00:23:00 +0000
Subject: [PATCH] David Brownell <david-b@pacbell.net>:
Doc update: say "jtag newtap ... -disable" records the
state after exiting the RESET state, matching the only
implementation we're working with so far (TI ICEpick-C).
Matching code updates. Now we can be sure that the
"enabled" flag value is correct after JTAG resets.
git-svn-id: svn://svn.berlios.de/openocd/trunk@2246 b42882b7-edfa-0310-969c-e2dbd0fdcd60
---
doc/openocd.texi | 7 ++++---
src/jtag/core.c | 2 ++
src/jtag/jtag.h | 6 ++++--
src/jtag/tcl.c | 10 +++++-----
4 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/doc/openocd.texi b/doc/openocd.texi
index 304fc62ac..7f73a4c33 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -2314,8 +2314,9 @@ A TAP may also provide optional @var{configparams}:
@itemize @bullet
@item @code{-disable} (or @code{-enable})
-@*Use the @code{-disable} paramater to flag a TAP which is not
-linked in to the scan chain when it is declared.
+@*Use the @code{-disable} parameter to flag a TAP which is not
+linked in to the scan chain after a reset using either TRST
+or the JTAG state machine's @sc{reset} state.
You may use @code{-enable} to highlight the default state
(the TAP is linked in).
@xref{Enabling and Disabling TAPs}.
@@ -5079,7 +5080,7 @@ and @command{irscan} commands are:
@end itemize
Note that only six of those states are fully ``stable'' in the
-face of TMS fixed (usually low)
+face of TMS fixed (low except for @sc{reset})
and a free-running JTAG clock. For all the
others, the next TCK transition changes to a new state.
diff --git a/src/jtag/core.c b/src/jtag/core.c
index 347196c0d..0cec11ad3 100644
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -792,6 +792,8 @@ static int jtag_reset_callback(enum jtag_event event, void *priv)
if (event == JTAG_TRST_ASSERTED)
{
+ tap->enabled = !tap->disabled_after_reset;
+
buf_set_ones(tap->cur_instr, tap->ir_length);
tap->bypass = 1;
}
diff --git a/src/jtag/jtag.h b/src/jtag/jtag.h
index 34a099b8e..956343eea 100644
--- a/src/jtag/jtag.h
+++ b/src/jtag/jtag.h
@@ -151,8 +151,10 @@ struct jtag_tap_s
const char* tapname;
const char* dotted_name;
int abs_chain_position;
- /// Is this TAP enabled?
- int enabled;
+ /// Is this TAP disabled after JTAG reset?
+ bool disabled_after_reset;
+ /// Is this TAP currently enabled?
+ bool enabled;
int ir_length; /**< size of instruction register */
u32 ir_capture_value;
u8* expected; /**< Capture-IR expected value */
diff --git a/src/jtag/tcl.c b/src/jtag/tcl.c
index fc113a398..8a7e38c3f 100644
--- a/src/jtag/tcl.c
+++ b/src/jtag/tcl.c
@@ -359,9 +359,6 @@ static int jim_newtap_cmd( Jim_GetOptInfo *goi )
LOG_DEBUG("Creating New Tap, Chip: %s, Tap: %s, Dotted: %s, %d params",
pTap->chip, pTap->tapname, pTap->dotted_name, goi->argc);
- /* default is enabled */
- pTap->enabled = 1;
-
/* deal with options */
#define NTREQ_IRLEN 1
#define NTREQ_IRCAPTURE 2
@@ -379,10 +376,10 @@ static int jim_newtap_cmd( Jim_GetOptInfo *goi )
LOG_DEBUG("Processing option: %s", n->name );
switch( n->value ){
case NTAP_OPT_ENABLED:
- pTap->enabled = 1;
+ pTap->disabled_after_reset = false;
break;
case NTAP_OPT_DISABLED:
- pTap->enabled = 0;
+ pTap->disabled_after_reset = true;
break;
case NTAP_OPT_EXPECTED_ID:
{
@@ -446,6 +443,9 @@ static int jim_newtap_cmd( Jim_GetOptInfo *goi )
} /* switch(n->value) */
} /* while( goi->argc ) */
+ /* default is enabled-after-reset */
+ pTap->enabled = !pTap->disabled_after_reset;
+
/* Did all the required option bits get cleared? */
if (0 == reqbits)
{
--
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