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using a 64k serial eeprom
Posted: Tue May 17, 2011 5:47 am
by shahin
Is there any reason why a 24LC64 eeprom wouldn't work with the FV-1? Our manufacturer stocks this part and we'd like to use it rather than bring in the 24LC32.
Posted: Tue May 17, 2011 10:48 am
by frank
I *think* it will work. My only concern is that the upper 4 bits in the upper address byte are "don't cares" in the '32 and I'm not sure if I shift out 0 or 1 for them, so try it one way (assume 0) and if that fails try it the other.
Posted: Wed May 18, 2011 5:28 pm
by dtech
Shanin:
Spin outputs 0000 for the don't care bits.
The actual sequence of FV1 loading from some program slot looks this way:
Start 1010000 0/W 1/A 00000010 1/A 00000000 1/A Start 1010000 1/R 1/A
ZZZZZZZZ 0/A repeats to load entire program.
Of course, all 1 can be considered Z, but it's easier to read the output this way.
At least it's how I have it on the papers scribbled off the scope.
Upper address bits change accordingly to the set programm, so that there is space for 512bytes for every programm.
Posted: Wed May 18, 2011 6:13 pm
by frank
Hi dtech,
Thanks for checking those don't care bits. It was on my list of things to look at today but I was unable to get to it.
Yes, programs are on 512 byte boundaries so upper bits of address directly map to program number and I just read in all bytes after sending the start address.