ETM/ETB documentation from David Brownell <david-b@pacbell.net>

git-svn-id: svn://svn.berlios.de/openocd/trunk@1803 b42882b7-edfa-0310-969c-e2dbd0fdcd60
__archive__
kc8apf 2009-05-18 04:40:11 +00:00
parent a931baa619
commit cafad4969c
1 changed files with 23 additions and 0 deletions

View File

@ -1014,6 +1014,7 @@ See the command ``jtag newtap'' for detail, but in brief the names you should us
@item @b{cpu}
@item @b{flash}
@item @b{bs}
@item @b{etb}
@item @b{jrc}
@item @b{unknownN} - it happens :-(
@end itemize
@ -1048,6 +1049,27 @@ helpful - for common programing errors.
If present, the MMU, the MPU and the CACHE should be disabled.
Some ARM cores are equipped with trace support, which permits
examination of the instruction and data bus activity. Trace
activity is controlled through an ``Embedded Trace Module'' (ETM)
on one of the core's scan chains. The ETM emits voluminous data
through a ``trace port''. The trace port is accessed in one
of two ways. When its signals are pinned out from the chip,
boards may provide a special high speed debugging connector;
software support for this is not configured by default, use
the ``--enable-oocd_trace'' option. Alternatively, trace data
may be stored an on-chip SRAM which is packaged as an ``Embedded
Trace Buffer'' (ETB). An ETB has its own TAP, usually right after
its associated ARM core. OpenOCD supports the ETM, and your
target configuration should set it up with the relevant trace
port: ``etb'' for chips which use that, else the board-specific
option will be either ``oocd_trace'' or ``dummy''.
@example
etm config $_TARGETNAME 16 normal full etb
etb config $_TARGETNAME $_CHIPNAME.etb
@end example
@subsection Internal Flash Configuration
This applies @b{ONLY TO MICROCONTROLLERS} that have flash built in.
@ -1640,6 +1662,7 @@ JTAG taps. GDB ends up talking via OpenOCD to one of the taps.
@item @b{cpu} - the main CPU of the chip, alternatively @b{foo.arm} and @b{foo.dsp}
@item @b{flash} - if the chip has a flash tap, example: str912.flash
@item @b{bs} - for boundary scan if this is a seperate tap.
@item @b{etb} - for an embedded trace buffer (example: an ARM ETB11)
@item @b{jrc} - for JTAG route controller (example: OMAP3530 found on Beagleboards)
@item @b{unknownN} - where N is a number if you have no idea what the tap is for
@item @b{Other names} - Freescale IMX31 has a SDMA (smart dma) with a JTAG tap, that tap should be called the ``sdma'' tap.