Flash Help!

CFI interface does not mean CFI compliant. The SST flash has a CFI interface, but it does not follow the CFI guidlines developed by Intel, AMD, Sharp, and Fujitsu. I have only read Intel and AMD versions.

For example, to do a CFI Query a device should send the following address and data values.

Address: 0x55, Data: 0x98 in one write cycle.

The SST CFI Query is done with

Address: 0x5555, DATA 0xAA

Address: 0x2AAA, Data 0x55

Address: 0x5555, Data 0x98 in three write cycles.

In order to get the SST flash to enter query mode, I had to write VHDL driver that decoded the single write cycle used by CFI compliant flash devices and generate the SST query command.

Pay attention to the data sheet, this is much easier.