On Mon, Jun 1, 2009 at 10:09 AM, David Brownell <davi...@pacbell.net> wrote: > So I'm trying to whack the user guide into shape, and those two > commands leave me a bit puzzled. Ergo, some questions and a few > observations. In no particular order here: > > drscan and irscan ... hmm, these seem to require numeric > TAP identifiers, vs the names preferred elsewhere. > > ==> Worth fixing at some point, yes? > > drscan and irscan ... what's the final state if the caller > doesn't specify "-endstate ..."? I hope/expect IDLE.
:-) I've suggested to retire jtag_add_end_state() which defines the default end state... > ==> if not specified, worth IMO doing so; random == bad. > > drscan and irscan ... as noted in [1] (top of p. 3-6) there > are only six "steady" states, with TMS fixed, where TCK > doesn't start walking through the JTAG state machine. > Of those, the two SHIFT states change register contents, > thus presumably walking through device state machines. > And RESET is all kinds of special case. > > Seems to me this adds up to advice that the endstate > should be either IDLE, DRPAUSE, or IRPAUSE. DRPAUSE and IRPAUSE are illegal end states for lots of good reasons... w.r.t. irscan/drscan they should be rewritten to use the same code + fix the various and sundry headaches that you have pointed out. Perhaps post 0.2? > tms_sequence ... we plan this to go away by 0.4 at the > latest, yes? (If not 0.3 ...) If not before 0.2? It could be made a debug feature, i.e. if you enable JTAG_DEBUG_IO(sp?). -- Øyvind Harboe Embedded software and hardware consulting services http://consulting.zylin.com _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
