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author | dbrownell <dbrownell@b42882b7-edfa-0310-969c-e2dbd0fdcd60> | 2009-10-05 08:20:28 +0000 |
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committer | dbrownell <dbrownell@b42882b7-edfa-0310-969c-e2dbd0fdcd60> | 2009-10-05 08:20:28 +0000 |
commit | 7c7467b34f11939fbce41e39dfa1b6b0e110a89c (patch) | |
tree | 13b56b2b83316f8e2bc4e402c9d994cf858471fe /doc | |
parent | 16a7ad5799ae488ad122648f2f74fe5d59e6c0c6 (diff) | |
download | openocd_libswd-7c7467b34f11939fbce41e39dfa1b6b0e110a89c.tar.gz openocd_libswd-7c7467b34f11939fbce41e39dfa1b6b0e110a89c.tar.bz2 openocd_libswd-7c7467b34f11939fbce41e39dfa1b6b0e110a89c.tar.xz openocd_libswd-7c7467b34f11939fbce41e39dfa1b6b0e110a89c.zip |
Add a new JTAG "setup" event; use for better DaVinci ICEpick support.
The model is that this fires after scanchain verification, when it's
safe to call "jtag tapenable $TAPNAME". So it will fire as part of
non-error paths of "init" and "reset" command processing. However it
will *NOT* trigger during "jtag_reset" processing, which skips all
scan chain verification, or after verification errors.
ALSO:
- switch DaVinci chips to use this new mechanism
- log TAP activation/deactivation, since their IDCODEs aren't verified
- unify "enum jtag_event" scripted event notifications
- remove duplicative JTAG_TAP_EVENT_POST_RESET
git-svn-id: svn://svn.berlios.de/openocd/trunk@2800 b42882b7-edfa-0310-969c-e2dbd0fdcd60
Diffstat (limited to 'doc')
-rw-r--r-- | doc/openocd.texi | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/doc/openocd.texi b/doc/openocd.texi index 32797fb3..8156de4d 100644 --- a/doc/openocd.texi +++ b/doc/openocd.texi @@ -2428,12 +2428,18 @@ The TAP events currently defined are: @itemize @bullet @item @b{post-reset} @* The TAP has just completed a JTAG reset. -For the first such handler called, the tap is still -in the JTAG @sc{reset} state. +The tap may still be in the JTAG @sc{reset} state. +Handlers for these events might perform initialization sequences +such as issuing TCK cycles, TMS sequences to ensure +exit from the ARM SWD mode, and more. + Because the scan chain has not yet been verified, handlers for these events @emph{should not issue commands which scan the JTAG IR or DR registers} of any particular target. @b{NOTE:} As this is written (September 2009), nothing prevents such access. +@item @b{setup} +@* The scan chain has been reset and verified. +This handler may enable TAPs as needed. @item @b{tap-disable} @* The TAP needs to be disabled. This handler should implement @command{jtag tapdisable} @@ -2450,7 +2456,7 @@ contents to be accurate), you might: @example jtag configure CHIP.jrc -event post-reset @{ - echo "Reset done" + echo "JTAG Reset done" ... non-scan jtag operations to be done after reset @} @end example @@ -2493,20 +2499,30 @@ does include a kind of JTAG router functionality. In OpenOCD, tap enabling/disabling is invoked by the Tcl commands shown below, and is implemented using TAP event handlers. So for example, when defining a TAP for a CPU connected to -a JTAG router, you should define TAP event handlers using +a JTAG router, your @file{target.cfg} file +should define TAP event handlers using code that looks something like this: @example jtag configure CHIP.cpu -event tap-enable @{ - echo "Enabling CPU TAP" ... jtag operations using CHIP.jrc @} jtag configure CHIP.cpu -event tap-disable @{ - echo "Disabling CPU TAP" ... jtag operations using CHIP.jrc @} @end example +Then you might want that CPU's TAP enabled almost all the time: + +@example +jtag configure $CHIP.jrc -event setup "jtag tapenable $CHIP.cpu" +@end example + +Note how that particular setup event handler declaration +uses quotes to evaluate @code{$CHIP} when the event is configured. +Using brackets @{ @} would cause it to be evaluated later, +at runtime, when it might have a different value. + @deffn Command {jtag tapdisable} dotted.name If necessary, disables the tap by sending it a @option{tap-disable} event. |