I have a NOR flash in order to configure my FPGA (cyclone V in this case). I have read the principle of a NOR flash operation and I have two questions:
1) What exactly happens in the erase operation, what it means, do the FPGA just writes '0' to all the space memory?
2) There is any difference between filling a NOR flash with all bits with the value '1' (like 0xffffffff.....) and mixed bits values like 0xaaaaaaaaaa or random values like 0x54321.... ?
In erase operation, NOR Flash will become 0xffffffff, it will become 0x00000000 if it is NAND flash.
NOR flash cell in its default state is logically equivalent to a binary "1" value, because current will flow through the channel under application of an appropriate voltage to the control gate, so that the bitline voltage is pulled down