SNES Repro message ID Type 1: 9090, ID Type 2: 9090

[StanMOI]

Hi Sanni,

I have this message :

Flashrom Writer 8bit
ID Type 1: 9090
ID Type 2: 9090
UNKOWN FLASHROM

It's my custom PCB with :

• Flash memory MX29LV640 or MX29LV800,
• bi-directional Transceivers Logic - Translators, Level Shifters (3v<->5v) LVC4245 and ALVC164245,
• and 100ohm resistors

What reason can it be ?
What can disturb reader to recognize chip?

[sanni]

I have seen the 9090 error before but I can't remember where or how it was fixed. Probably best to attach one of those cheap logic analyzers to the 29LV800 and check that WE/CE/OE are triggered correctly. And also check that the voltage at the 29LV is correct.

[StanMOI]

Thanks SANNI,
Please let me know if you will find how it was solved.

About WE of flash, it's OK, it's tied to WR (pin 54 of cartridge edge).
About CE of flash, it's should be OK too, its trigged to /RD (pin 23 of cartridge edge)
About OE of Level Shifters i'am not sure...
Should se Function Table to understand how to use them to get worked in two directions.

[trgkaigit]

Please update this thread if you figure this out. I have a repro giving the same 9090 ID UNKNOWN FLASHROM error with a 29LV160, and confirming a valid connection existed between WE and Pin 54 didn't solve it.

[StanMOI]

Can you show Picture of your PCB ?

My error problem is still not resolved.
I’am not sure if « level shifters » have right connections.
It’s my custom PCB, so it can be not perfect cause it’s my first version 🙂