SST25VF080B MUST be unlocked before each write command
This is just a post to help someone else save a week or two of frustration. On my new update to my product, I went from an SST25VF040 to an SST25VF080B, and could not get it to write no matter what I did. I tried erasing the chip first, various SPI types including both MCC code, and nothing worked. I finally got the status register to read, and found that all the block protect bits were set, so I then tried to unlock them, but no joy.
I then re-re-re-read the datasheet, and found the import information - the write protect bit is SET AFTER EVERY WRITE OR ERASE COMMAND! You have to unlock the bit with a WREN() command BEFORE EVERY SINGLE WRITE OPERATION!
Whoever came up with that procedure, and then DIDN'T DOCUMENT IT should be boiled in poison ivy oil!