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David Brownell <david-b@pacbell.net> More jtag_add_reset() cleanup: 

Unify the handling of the req_tlr_or_trst parameter.  Basically,
JTAG TMS+TCK ops ("TLR") is always used ... unless TRST is a safe
option in this system configuration.

git-svn-id: svn://svn.berlios.de/openocd/trunk@2622 b42882b7-edfa-0310-969c-e2dbd0fdcd60
This commit is contained in:
oharboe 2009-08-25 19:58:06 +00:00
parent 6f359fba68
commit 86b49612a6
1 changed files with 18 additions and 17 deletions
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35
src/jtag/core.c
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@ -588,6 +588,23 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
int new_srst;
int new_trst = 0;
/* JTAG reset (entry to TAP_RESET state) can always be achieved
* using TCK and TMS; that may go through a TAP_{IR,DR}UPDATE
* state first. TRST accelerates it, and bypasses those states.
*
* RESET_TRST_PULLS_SRST is a board or chip level quirk, which
* can kick in even if the JTAG adapter can't drive SRST.
*/
if (req_tlr_or_trst) {
if (!(jtag_reset_config & RESET_HAS_TRST))
trst_with_tlr = 1;
else if ((jtag_reset_config & RESET_TRST_PULLS_SRST) != 0
&& !req_srst)
trst_with_tlr = 1;
else
new_trst = 1;
}
/* FIX!!! there are *many* different cases here. A better
* approach is needed for legal combinations of transitions...
*/
@ -614,12 +631,6 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
return;
}
/* if TRST pulls SRST, we reset with TAP T-L-R */
if (((jtag_reset_config & RESET_TRST_PULLS_SRST) && (req_tlr_or_trst)) && (req_srst == 0))
{
trst_with_tlr = 1;
}
if (req_srst && !(jtag_reset_config & RESET_HAS_SRST))
{
LOG_ERROR("BUG: requested SRST assertion, but the current configuration doesn't support this");
@ -627,17 +638,6 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
return;
}
if (req_tlr_or_trst)
{
if (!trst_with_tlr && (jtag_reset_config & RESET_HAS_TRST))
{
new_trst = 1;
} else
{
trst_with_tlr = 1;
}
}
new_srst = req_srst;
/* Maybe change TRST and/or SRST signal state */
@ -831,6 +831,7 @@ static int jtag_reset_callback(enum jtag_event event, void *priv)
{
tap->enabled = !tap->disabled_after_reset;
/* current instruction is either BYPASS or IDCODE */
buf_set_ones(tap->cur_instr, tap->ir_length);
tap->bypass = 1;
}