I am looking to attempt to read and dump a mystery memory. By mystery, I mean that the parts are under blobs on a board (picture attached.) I have deducted a rough pinout:
2 CHIP DETECT (connected to 3.3V on cart)
There are two memories on the board. They are using CS2 and CS3. Clock and data lines are shared between them. The closest interface that I can come up with is a quad-SPI flash chip or possibly even a true SD card interface (hopefully not since the standards are closed for that.)
I plan to have it xray'd at work tomorrow, so perhaps I will find a chip identifier underneath the blobs, but I am wondering if anyone has any thoughts on how to start reading it in the meantime.
I did connect this up to a logic analyzer in the original circuit to watch the transactions and it appeared that the CS line was only pulsed HIGH for one cycle and a stream of nibbles came out of the data lines. The problem was that the stream was not a fixed width which made decoding it a bit confusing. There did seem to always be a consistent pattern to the first four nibble, so I am assuming that is an address.
The fact that the CS line was only strobed for one clock has me second guessing whether they are really considered "CS" lines. I would have expected it to be held in one state or another for the entire duration of one transaction.
Any thoughts? I can post some LA screen caps as well. But I will probably have had this xray'd by then.