EPCS4 Programming Errors

quartus programmer doesn't check for the protection bits when performing the erase and program operations. it will continue its operation even though there are protected sectors, but the protected sectors won't be overwritten.

to reset the block protect bits in the status register, try to look at this megafunction: altasmi_parallel; it contains all the operations regarding the EPCS device such as block erase, sector erase, read status, write status. you can use the write status operation to reset the block protection bits.