Hi all,

Well, the little dickens kept me waiting for 54 hours this time, but
fail it did

This time I was set up to catch it fail, repeatedly

Here are a couple of screen shots

http://home.clear.net.nz/pages/joecolquitt/sdhc.html

The analyser labels are

busy - dsPIC has received file number (fn data, fn clk), and holds
this line up until the file has finished, as a signal to the 18F

clk - SPI clock (picture resolution to low to see bunches of 8)

di / do - data I/O. To the right, at the start of each of the three blocks,
you'll see the CMD17 go out, a short response from the card, a wait
(high with 0xFF) for the 0xFE token and then card data coming out

fe det - shows the detection of the 0xFE token of the first block
of the file

block swap - shows the swapping of two RAM blocks, one is full
of data to be processed, the other is being loaded

cs - card /CS

The first picture is of a good read. It shows the file number being
received, '>74 clocks with CS high', a few preparatory CMD and
then the block reading. fe det is the analyser trigger (red line).

The second picture is of a fail. The file number is received, busy
goes high, > 74 clocks, then a whole lot of nothing except clk

I used the time from fn clk high to fe det as a 16ms timeout period
for a another PIC to trigger the analyser. IOW if there was no
activity for 16ms then the analyser would be triggered. Red line is
out of shot to the right

The first thing I tried was a couple of other dsPICs, but that made
no difference, the card repeatedly failed again within a minute, and
with that bad data (?) 'click' noise too, so I *think* I can rule out
the dsPIC's SPI module. I also re-programmed the original dsPIC
but same result

Hmmm. Now what ? ................

The time to failure has me stumped now. It was at first about 18
hours (60,000+ accesses), then 30 hours (100,000+) and this
latest one, 54 hours (190,000+)

I'm going to have to get some more cards and circuits running
and resolve myself to a lot of waiting

Joe


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