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) {