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Mike- What can programming Flash do to hold up JTAG on the DSK board? It must be DSK board specific, because normally -- as long as C67xx reset is not held and JTAG signals are still connected and healthy - JTAG should be enabled. I suppose the CCS driver is doing something else it needs to initialize, not just JTAG, and the program running from Flash has somehow got in the way. -Jeff -------- Original Message -------- Subject: Re: [c6x] can't connect to target after flashburn Date: Wed, 3 Mar 2004 21:34:50 -0800 (PST) From: Mike Dunn <> To: stino_rides <>, Hello Stijn, It is possible for the programmation of the FLASH to prevent the emulator from taking control. One way to get around the problem is to bring up the board in HPI boot mode. After reset the DSP will "hang", until the emulator comes up. The only trick is to "get there"... Since I do not know your capabilities or situation, I will provide a couple of suggestions. [Refer to the DSK schematics, page 5, to see what is going on] IF YOU DO NOT UNDERSTAND ANY OF THE FOLLOWING, IGNORE IT OR GET HELP! 1. Use a fine "clip lead" to connect U20 pin 5 [a convenient, and marked, corner pin] to ground [the JTAG connector pin 4 is easy]. you can leave this connected as long as you need it. 2. solder a very short piece of wire in the R82 position - this will cause HPI boot to be permanent. 3. [my favorite] Run a piece of small gauge wire from "the R82 pad that connects to R83" to "the switched pin of unused switch #4" [I think that it is the one near the board edge]. Use sw 4 to enable/disable HPI boot mode.Happy "booting",mikedunn stino_rides <> wrote: Hi I encountered a pretty severe problem today: i wanted to test the flashburn program, I did this by burning the supplied FlashBlink example, The burned program does start without any problems, but now I cannot connect to the c6711dsk anymore. ('Can't initialize target cpu etc.). I tried everything (reset, power on/off) but it does not work.. I did not find any jumpers or so to disable booting from flash, anyone knows what I can do? Thanks, Stijn |
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[Fwd: Re: can't connect to target after flashburn]
Started by ●March 4, 2004
Reply by ●March 8, 20042004-03-08
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Hello Jeff,
I agree with you - if all is well.
it is true, JTAG is enabled - but it is a long journey for the JTAG signals
to traverse from the JTAG clock domain to and from the CPU. There are
certain synchronizations and timing windows that must occur for emulation
transactions to succeed [like halting the DSP for one].
I do not know for sure the exact cause and I have only known this
situation to occur when the DSP was executing something other than legal
code. I speculate that one possible cause is a memory cycle starts but
never ends - this would lock out emulation control until the cycle
completes.
My most recent empirical evidence comes from the 6711 DSK. I jumpered
it to change the endianness and I could not get emulation control 90%
percent of the time [since BE mode was 'booting' from the high byte of
the data bus the DSP was eating garbage...]. I have also had similar
experiences with "trashed flash". I think the root of the problem has to
do with "executing garbage" and an instruction set that is not fully
decoded.
regards,
mikedunn
Jeff Brower <j...@signalogic.com> wrote: Mike- |
