On Dec 19, 2008, at 12:25 PM, Dirk Behme wrote:
* Thanks to Dave, Rick and I got the "TI doc" now.
And it has raised more questions.
* I now get -- cut -- > openocd -s lib/openocd/ Open On-Chip Debugger 1.0 (2008-12-19-17:38) svn:1261 BUGS? Read http://svn.berlios.de/svnroot/repos/openocd/trunk/BUGS $URL: svn://svn.berlios.de/openocd/trunk/src/openocd.c $ jtag_speed: 1Info: JTAG tap: omap3530.jrc tap/device found: 0x0b7ae02f (Manufacturer: 0x017, Part: 0xb7ae, Version: 0x0)Info: JTAG Tap/device matched Warning:no gdb ports allocated as no target has been specified Warning:no tcl port specified, using default port 6666 -- cut --This is with Flyswatter, TinCanTools' adapter and BeagleBoard. I think this shows that recent svn works with Flyswatter :)
At least one piece of the puzzle is filled in. After a reset, the JRC needs 10 TCK pulses to wake up the JTAG power domain. So, the first DRSCAN returning 0xffffffff and the first IRSCAN seemingly having no effect after a reset is because the hardware turns on partway through the state machine. I think we can address this in the config fairly easily.
The bad part is that I now know that the "TI doc" doesn't tell us the IR value for IDCODE. So, the only reason we are getting a match for the JRC is because the first IRSCAN being sent out to the JTAG interface is getting ignored and the hardware comes up with the IDCODE value already loaded into the IR. If the JTAG hardware is already up and running, chain examination will likely fail since the initial IRSCAN will be acted upon and we will set the IR to a value with an unknown meaning.
The good news is that we can _possibly_ bring up the DAP and not attempt a second chain examination. It means the output of scan_chain will be wrong in some ways, but at the very least, we should be able to manually query the DAP. If nothing else, being able to talk to the DAP means that development on Cortex-A8 target support can start even if the JRC isn't behaving perfectly.
-- Rick Altherr [email protected]"He said he hadn't had a byte in three days. I had a short, so I split it with him."
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