Hello all, Recently we have started some test production, and on about 1% of the units claimed to be defective by our test software. I took a closer look on these units and I have noticed a huge offset on 1 or 2 of the ADC channels. At 0V level it showed the same value as the other -good- ones at 1V, while the whole measuring range is calibrated to 3V. Did anyone meet such a symptom before? Is it a typical DSP fault or some kind of design flaw? I have checked all voltages corresponding to the analog inputs such as Vdda and Vssa and their values are OK. Any suggestions and ideas are welcome, Georg Bende Softwareentwickler Abteilung Elektronik Dr. Fritz Faulhaber GmbH & Co KG Daimlerstr. 23 71101 Schaich Tel: +49 7031 638294 |
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56F807 DSP failures
Started by ●July 6, 2004
Reply by ●July 6, 20042004-07-06
Could your problem be related to the ettara issue of
the ADCs not working below a 24mV?
Personally, I think this is something Motorola needs to
fix, and if I had known about the problems before I started development I would
not be using these chips today. I'm using the 803 and I think they
are on Rev F Silicone and still have not fixed the problem. I know
the next time I choose a chip it may not be Motorola because of this
lingering issue.
I've seen that microchip has a new 16-bit dsp
out....
Jacob
From: Bende Georg [mailto:g...@faulhaber.de] Sent: Tuesday, July 06, 2004 3:05 AM To: m...@yahoogroups.com Subject: [motoroladsp] 56F807 DSP failures Recently we have started some test production, and on about 1% of the units claimed to be defective by our test software. I took a closer look on these units and I have noticed a huge offset on 1 or 2 of the ADC channels. At 0V level it showed the same value as the other -good- ones at 1V, while the whole measuring range is calibrated to 3V. Did anyone meet such a symptom before? Is it a typical DSP fault or some kind of design flaw? I have checked all voltages corresponding to the analog inputs such as Vdda and Vssa and their values are OK. Any suggestions and ideas are welcome, Georg Bende Softwareentwickler Abteilung Elektronik Dr. Fritz Faulhaber GmbH & Co KG Daimlerstr. 23 71101 Schaich Tel: +49 7031 638294 _____________________________________ Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. _____________________________________ About this discussion group: To Join: m...@yahoogroups.com To Post: m...@yahoogroups.com To Leave: m...@yahoogroups.com Archives: http://www.yahoogroups.com/group/motoroladsp More Groups: http://www.dsprelated.com/groups.php3 |
Reply by ●July 6, 20042004-07-06
We have used the 807 in several high volume products and have not
noticed any A/D problems relating to the processor.
We did have some minor issue on our part due to boards being
calibrated with a different power supply than used in the field (and off by
a tenth of a volt or so) , resulting in slight calibration error until we
realized the problem.
Howard
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Reply by ●July 6, 20042004-07-06
Nachricht
The problem I mentioned does not sound like your
problem.
We havn't had any 807 issues from our experience. One minor
problem that I can recall was that we had to use 4 Wait States (WS) for our
external SRAM because of the impossibly tight requirements for the timing spec
combined with poor WS granularity (0/4/8/12WS supported). With 0WS, it worked on
most units, but failed (usually at high temperature) on a small percentage of
chips. We got around this by keeping critical stuff in internal
SRAM.
Howard
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Reply by ●July 22, 20042004-07-22
Hello all,
I am wroking on 56F801 and am very much new to DSP itself.
I have been trying to modulate certain signal through FSK.
And ,I am not able to figure out the register which I need to set to get
the required sampling frequency.
Can anyone help me on this..???
Thanking you,
Mrugesh.
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