I have a design that used an M95010-W and can read the Status as well as set the WEL bit and read it back in the status. However when I try to write data starting at address 0 with the command string 0x02 0x00 followed by data in the same SPI frame and then read back with the command string 0x03 0x00, the data that follows is all 0 for the addresses of the data that was written and all 0xFF for the rest of the array.
I also noticed that on the first attempt that between the write and the read I left the WEL bit set and it the WEL bit seems to be persistent until it is commanded to set to 0. This is not disclosed in the data sheet for the part as far as I can tell.
I made a second attempt to write data and read it back while setting the WEL bit before the write followed by returning the WEL bit to 0 and then doing the read. This did not change the behavior of addressed array contents setting to 0 regardless of the data.
After power cycling the array contents written to retain all 0 and cannot be programmed to anything else. So I am stuck with 0 data. As far as I can tell this part does not have an erase command, so now the part is useless.
I am running the part at 1MHz so speed should not be the issue.
