6.4.2 Write-Protect Enable Function

The WRSR instruction allows the user to enable or disable the Write-Protect (WP) pin through the use of the Write-Protect Enable (WPEN) bit. When the WPEN bit is set to logic ‘0’, the ability to write to the EEPROM array is determined by the values of the Block Write-Protect (BP1, BP0) bits. The ability to write to the STATUS register is controlled by the WEL bit. When the WPEN bit is set to logic ‘1’, the STATUS register is read-only.

Hardware Write Protection is enabled when both the WP pin is low and the WPEN bit is set to logic ‘1’. When the device is Hardware Write‑Protected, writes to the STATUS register—including the Block Write‑Protect, WEL and WPEN bits—as well as writes to the sections of the memory array selected by the Block Write‑Protect bits, are disabled. When Hardware Write Protection is enabled, writes are allowed only to sections of memory that are not block‑protected.

Hardware Write Protection is disabled when either the WP pin is high or the WPEN bit is set to logic ‘0’. When Hardware Write Protection is disabled, writes are allowed only to sections of memory that are not block‑protected. Refer to Table 6-5 for additional information.