RE: [ECOS] Enable EDB7xxx interrupts

["Lewin A.R.W. Edwards" <larwe at larwe dot com>]

>I did test the EINT1 interrupt on the CPU as you suggested with the
>multi tester by pulling it low, and fired just fine.

OK, that means your software is good, but we still haven't narrowed the 
problem down beyond these possibilities:

* PS6700 not configured correctly to generate interrupts
* PS6700 configured correctly and generating interrupts, but those 
interrupts not [electrically] making it to the CPU
* PS6700 fried

If you can talk to the chip at all then it is not impossible but quite 
unlikely that the chip is hosed; it wouldn't be high on my list of 
priorities to investigate. The other Cirrus EDB problem Gary was talking 
about was a pick-n-place error wherein some boards had the wrong part 
fitted instead of the EEPROM required for the CS8900's config info, it 
wasn't a subtle problem at all.

> > Pop a DSO on the actual pin of the PS6700 (if you have one)
> > and capture the
> > timeframe surrounding your interrupt event...
>
>What's a DSO?  Do you mean a logic analyzer?

Digital Storage Oscilloscope.

>Yep, already did that, a jumper is required for the FIQ, but not the IRQ
>line.  The FIQ jumper has been on the entire time however.

If the line is tied to another outputs from a different device, or has an 
overly aggressive pullup/pulldown then the 6700 might not be able to pull 
the CPU's input high/low enough to assert an interrupt request if the other 
device's output is not tristated. When you poked it with your wire, you 
forced the issue.

If possible it could be instructive to isolate the int out pin(s) from the 
6700 and see if they show activity when electrically isolated from the rest 
of the circuit.


-- Lewin A.R.W. Edwards
Embedded Engineer, Digi-Frame Inc.
Work: http://www.digi-frame.com/
Tel (914) 937-4090 9am-6:30pm M-F ET
Personal: http://www.larwe.com/ http://www.zws.com/

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that knows not victory nor defeat."
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