Can I use JTAG to flash an eeprom in and out of circuit?

[lookimback]

Baically, what I'm asking is if that, knowing the pinout, could I connect the JTAG leads directly to an eeprom and perform read/write operations regardless of whether there are JTAG test points on the board. And out of circuit do the same, but in that situation I'd use one of those flash adapter things which would then be plugged into a breadboard. I've looked into the actual eeprom flash tools and, even in the $600+ range, there are always eeproms I'd need to flash which aren't supported.

[stj]

Re: Can I use JTAG to flash an eeprom in and out of circuit?

no, eeproms arent jtag, they are i2c or microwire or spi interfaced.

what part numbers do you need to flash?

[lookimback]

Re: Can I use JTAG to flash an eeprom in and out of circuit?

I'll have to look when I get home. But in general, I'm looking for something universal which could be done based on pin out, as opposed to the "universal" programmers which only work if it's a supported eeprom. Even something PC based would be fine. I can always make my own hardware interface.

[lookimback]

Re: Can I use JTAG to flash an eeprom in and out of circuit?

I forgot I took a picture of it last night. It's an S29GL128N11TFI01. I am unable to find an exact main board for the 50" TV I'm working on, but can find the exact board in a 42" model. I'm certain the only difference is firmware. I could probably just pull the eeproms and swap them, but if I screw up then I'll have no way of going back. Trying to reprogram it, I'll at least have a backup of the fw.

[stj]

Re: Can I use JTAG to flash an eeprom in and out of circuit?

thats a 56pin flashchip, not an eeprom.

you need to jtag those through the cpu, or lift them off the board and use an expensive socket & programmer.

[lookimback]

Re: Can I use JTAG to flash an eeprom in and out of circuit?

I was going over the data sheet for it and see there's a possibility it could be password protected. Would that stop a read operation? Also, how does one figure out the JTAG test points?