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berni
2 Posts |
 Posted - 08/19/2018 : 02:56:30
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I have created a FRAM drop in replacement for the DS1220 and DS1230 chips. It uses the Cycpess FM18W08 chip for both and as far as i can tell is electrically and speed wise identical to the Dallas chips its replacing.
Photos here:
https://imgur.com/a/GmKHW4c
For the DS1220 device i could never get the programmer to work. I have looked at the signals on the pins and everything seams to be just fine, the data lines are moving as the chip is read, yet the programmer reads garbage.
The DS1230 retrofit module works just fine when the programmer is set for a DS1230 and will read the DS1220 one in that mode too if i stick it in an adapter to match the pinout to it.
I don't have a real DS1220 chip on hand because i still have to desolder it from the hard to get to board in the equipment im repairing. But looking at the datasheet the DS1230 and DS1220 are electricaly and timing wise identical apart from one having 32KB while the other is only 2KB, having less address lines as a result.
Also about your software. The device selector is not very helpful at all in finding a compatible chip. I would MUCH prefer if it would show the pinout and voltages for every chip you click on so that i can find a match quickly rather than having to google a datasheet for every chip in the list to find one with a matching pinout. The software must know the pinout of the chip to be able to program it so why not show the pinout to me! |
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| Reply #1
anniel
2572 Posts |
Posted - 08/19/2018 : 08:00:31
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quote:
Originally posted by berni
I have created a FRAM drop in replacement for the DS1220 and DS1230 chips. It uses the Cycpess FM18W08 chip for both and as far as i can tell is electrically and speed wise identical to the Dallas chips its replacing.
Photos here:
https://imgur.com/a/GmKHW4c
For the DS1220 device i could never get the programmer to work. I have looked at the signals on the pins and everything seams to be just fine, the data lines are moving as the chip is read, yet the programmer reads garbage.
The DS1230 retrofit module works just fine when the programmer is set for a DS1230 and will read the DS1220 one in that mode too if i stick it in an adapter to match the pinout to it.
I don't have a real DS1220 chip on hand because i still have to desolder it from the hard to get to board in the equipment im repairing. But looking at the datasheet the DS1230 and DS1220 are electricaly and timing wise identical apart from one having 32KB while the other is only 2KB, having less address lines as a result.
Also about your software. The device selector is not very helpful at all in finding a compatible chip. I would MUCH prefer if it would show the pinout and voltages for every chip you click on so that i can find a match quickly rather than having to google a datasheet for every chip in the list to find one with a matching pinout. The software must know the pinout of the chip to be able to program it so why not show the pinout to me!
Try changing the VCC to 5.5V. |
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| Reply #2
berni
2 Posts |
Posted - 08/28/2018 : 10:18:11
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quote:
Originally posted by anniel
Try changing the VCC to 5.5V.
Sorry for the late reply. I didn't quite figure out a quick way to raise the voltage to 5.5V. But later on once i got the original DS1220 chip out of there it did read that chip fine, im guessing something about the timing is right on the edge there.
In any case i did manage to program my replacement chips just fine using my custom adapter. They work just fine in place of the original Dallass chips in the HP Multimeter, except these have a 140 year data retention. |
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| Reply #3
anniel
2572 Posts |
Posted - 09/03/2018 : 05:01:18
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quote:
Originally posted by berni
quote:
Originally posted by anniel
Try changing the VCC to 5.5V.
Sorry for the late reply. I didn't quite figure out a quick way to raise the voltage to 5.5V. But later on once i got the original DS1220 chip out of there it did read that chip fine, im guessing something about the timing is right on the edge there.
In any case i did manage to program my replacement chips just fine using my custom adapter. They work just fine in place of the original Dallass chips in the HP Multimeter, except these have a 140 year data retention.
In the DEVICES.TXT. |
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| Reply #4
anniel
2572 Posts |
Posted - 09/03/2018 : 05:04:16
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quote:
Originally posted by Genevra
try changing the vcc to 5.5v
+1 |
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DS1220 reads/writes garbage in GQ4x4
