topic Trouble with new design using DSP56F805 in Other NXP Products

Trouble with new design using DSP56F805

CCStuart — Sat, 30 Dec 2006 01:46:04 GMT

I created a design using the DSPF805 processor about 5 years ago. It worked fine and never had any problems. I just created a new design using the same DSP (now 5 years later) and neither test board works. When I try to connect to the DSP through the JTAG port I get "Core is not responding" I thought this was going to be a simple thing because I have already used this DSP before. I have triple checked all the connections, VCC, GND levels....everything around the chips seems to be fine. When I hold it in reset I get the crystal oscillator output signal on the CLKO pin...and the oscilator section is working fine. Its just like is is sitting there with some simple stupid reason for not communicating with the software. It is a different chip revision, but I can't hardly imagin that would be the reason...could it? There does not seem to be any major change in the Irrata documentation. Now I am dead in the water with a project that is way overdue. Any input would be appreciated!

Re: Trouble with new design using DSP56F805

marks — Tue, 02 Jan 2007 22:53:21 GMT

I vaguely remember someone having trouble maintaining communication with the JTAG probe on a DSP once. Turned out that there was a "wait" instruction in the code (or something like that) causing the processor not to respond. Could this be the cause? Just a shot in the dark.

Re: Trouble with new design using DSP56F805

AgentK — Sat, 20 Jan 2007 00:07:15 GMT

Did you ever get this sorted? I had this problem yesterday with a wiggler jtag programmer, & it turned out to be that I didn't have a flash .cfg file set in the M56800E target settings.

Re: Trouble with new design using DSP56F805

CCStuart — Sat, 20 Jan 2007 00:19:19 GMT

Yes actually I got it resolved thanks. It turned out that there is a "test" pin on the dsp that needs to be pulled low for "normal chip operation" and I had inadvertantly left it floating. After I tied it to ground the chips woke up. UURRRGGG. Details!