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93C66B - APC SYBT5 checksum changes on read

Posted: Tue Mar 05, 2019 5:07 am
by masterit
Hello,

first off i wanted to thank you for this programmer. when i was looking for programmers after trying to dust off my EMP-10 i found most were knockoffs and had no websites. i chose this one based on the support and examples online.

now to my question.


I have a few micro 93c66 eeproms i need to program these are programmed in the zif connector.
however i'm facing a problem.
it seems the revelprog isn't consistently reading or writing the eeproms. the crc checksum changes occasionally.
even when it doesn't change i see portions of the memory not loading correctly once placed back in the UPS.

the power on the revelprog seems consistent so im not sure what i may be doing wrong apart from operator error?

can you also explain the swapbyte setting? i read the manual but don't understand if it applies to my issue.
i'm using version 1.8.0.

thank you.

Re: 93C66B - APC SYBT5 checksum changes on read

Posted: Tue Mar 05, 2019 9:55 am
by ArT
Hello,

Let's start from checking few things:
- does programmer pass hardware test? please share screenshot from it
- are you using stock USB 2.0 HS cable directly plugged to USB port (without dock station, hubs etc.) ?
- how about when you load random data to buffer (CTRL + R) and write it to 93c66 and next make 10x read - is CRC changing each time?
- could you send me photo how you put eeprom in zif socket?

PS. swap byte is for 16-bit devices (most 93xx) where you can have MSB first or LSB first, e.g. 0xABCD -> swap byte -> 0xCDAB

BR
Artur

Re: 93C66B - APC SYBT5 checksum changes on read

Posted: Sat Mar 09, 2019 1:33 am
by masterit
Yes it passes.
{6E805B6D-17E0-4C43-867B-EB990AC653EA}.png.jpg
Hardware test
{6E805B6D-17E0-4C43-867B-EB990AC653EA}.png.jpg (399.66 KiB) Viewed 1115 times

the usb cable is connected directly to the computer.

i'm able to read and write to the chip but i2c chips cannot read or write at all.
could it be a problem with the programmer itself?

Re: 93C66B - APC SYBT5 checksum changes on read

Posted: Sun Mar 10, 2019 7:42 pm
by ArT
2 voltages for 5V rail looks low, could you make hardware test again and click "CTRL + 1"? It should display more measurements. Please make screenshot we will see. Maybe programmer is damaged.

How about when you load random data to buffer (CTRL + R) and write it to 93c66 and next make 10x read - is CRC changing each time? Do you have communication error on all I2C chips?

Re: 93C66B - APC SYBT5 checksum changes on read

Posted: Tue Mar 12, 2019 3:19 am
by masterit
The new Hardware test:
Annotation 2019-03-11 220628.jpg
Hardware Test-v2
Annotation 2019-03-11 220628.jpg (60.89 KiB) Viewed 1108 times

i removed other peripherals from the motherboard usb ports. and it looks more stable now.
i do think my psu is a bit underpowered as you surmised. i may replace it in that case.
is there any reason why these programmers did not come with an option for an external power supply?

the checksum is returning verification okay now on 10+ reads so that may have been the problem.

for i2c chips, i just tried reading and writing to a batch of 24LC128-I's and it works too. so the issue may have been the power all along?

Re: 93C66B - APC SYBT5 checksum changes on read

Posted: Tue Mar 12, 2019 9:56 am
by ArT
That's good that it is working now.
HW test looks fine now.

ps. you can connect external power supply in external circuit and it will also power programmer circuit (programmer is only usb powered) - please check Chapter 5 in manual for details.