diff options
author | oharboe <oharboe@b42882b7-edfa-0310-969c-e2dbd0fdcd60> | 2009-06-01 19:58:20 +0000 |
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committer | oharboe <oharboe@b42882b7-edfa-0310-969c-e2dbd0fdcd60> | 2009-06-01 19:58:20 +0000 |
commit | 7662bbeaa5da95abc1be2ca5dc686825fbeafccc (patch) | |
tree | 74be09796780cf534c1538b449dbee77753b9f4b /src/jtag/jtag.c | |
parent | 414245c9ce4ec112dc704664f56b268d27be3218 (diff) |
added jtag_add_statemove() helper fn(actual fn written by Dick Hollonbeck, I just moved it).
git-svn-id: svn://svn.berlios.de/openocd/trunk@1980 b42882b7-edfa-0310-969c-e2dbd0fdcd60
Diffstat (limited to 'src/jtag/jtag.c')
-rw-r--r-- | src/jtag/jtag.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c index c9167f41..4ed08971 100644 --- a/src/jtag/jtag.c +++ b/src/jtag/jtag.c @@ -3719,3 +3719,90 @@ static int handle_tms_sequence_command(struct command_context_s *cmd_ctx, char * } /*-----</Cable Helper API>--------------------------------------*/ + + +/** + * Function jtag_add_statemove + * moves from the current state to the goal \a state. This needs + * to be handled according to the xsvf spec, see the XSTATE command + * description. + */ +int jtag_add_statemove(tap_state_t goal_state) +{ + int retval = ERROR_OK; + + tap_state_t moves[8]; + tap_state_t cur_state = cmd_queue_cur_state; + int i; + int tms_bits; + int tms_count; + + LOG_DEBUG( "cur_state=%s goal_state=%s", + tap_state_name(cur_state), + tap_state_name(goal_state) ); + + + /* From the XSVF spec, pertaining to XSTATE: + + For special states known as stable states (Test-Logic-Reset, + Run-Test/Idle, Pause-DR, Pause- IR), an XSVF interpreter follows + predefined TAP state paths when the starting state is a stable state and + when the XSTATE specifies a new stable state (see the STATE command in + the [Ref 5] for the TAP state paths between stable states). For + non-stable states, XSTATE should specify a state that is only one TAP + state transition distance from the current TAP state to avoid undefined + TAP state paths. A sequence of multiple XSTATE commands can be issued to + transition the TAP through a specific state path. + */ + + if (goal_state==cur_state ) + ; /* nothing to do */ + + else if( goal_state==TAP_RESET ) + { + jtag_add_tlr(); + } + + else if( tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state) ) + { + /* note: unless tms_bits holds a path that agrees with [Ref 5] in above + spec, then this code is not fully conformant to the xsvf spec. This + puts a burden on tap_get_tms_path() function from the xsvf spec. + If in doubt, you should confirm that that burden is being met. + */ + + tms_bits = tap_get_tms_path(cur_state, goal_state); + tms_count = tap_get_tms_path_len(cur_state, goal_state); + + assert( (unsigned) tms_count < DIM(moves) ); + + for (i=0; i<tms_count; i++, tms_bits>>=1) + { + bool bit = tms_bits & 1; + + cur_state = tap_state_transition(cur_state, bit); + moves[i] = cur_state; + } + + jtag_add_pathmove(tms_count, moves); + } + + /* else state must be immediately reachable in one clock cycle, and does not + need to be a stable state. + */ + else if( tap_state_transition(cur_state, true) == goal_state + || tap_state_transition(cur_state, false) == goal_state ) + { + /* move a single state */ + moves[0] = goal_state; + jtag_add_pathmove( 1, moves ); + } + + else + { + retval = ERROR_FAIL; + } + + return retval; +} + |