************************************************************************ ************************************************************************ ** ** ** Application notes for Microchip Memory devices ** ** ** ** (Informal Document) ** ** ** ** To find the application notes for your device search for the ** ** 'core' part name. As an example using the 25HP512 8 pin SOIC ** ** you would search this document for the entry "25HP512" ** ** ** ************************************************************************ ************************************************************************ ************************************************************************ 25AA160 ---------- 25LC160 ---------- 25AA320 ---------- 25LC320 ---------- 25AA640 ---------- 25LC640 ---------- There are four levels of Block Protection that can be supported on these devices: Start/End Block Protection Addresses (BP1), (BP0) 25AA160 Security Fuse settings: SF2, SF1 25LC160 ------------------------------------ ------------ 0, 0 None 0, 1 $0600->$07FF 1, 0 $0400->$07FF 1, 1 $0000->$07FF ---------------------------------------------------- Start/End Block Protection Addresses (BP1), (BP0) 25AA320 25AA640 Security Fuse settings: SF2, SF1 25LC320 25LC640 ------------------------------------ ------------ ------------ 0, 0 None None 0, 1 $0C00->$0FFF $1800->$1FFF 1, 0 $0800->$0FFF $1000->$1FFF 1, 1 $0000->$0FFF $0000->$1FFF ---------------------------------------------------------------- Enabling the "Erase EE device" option will ONLY remove all block protection. NOTE: The "Erase EE device" option must be enabled when re-programming the device in order to remove the Block Protection. NOTE: The "Erase EE device" option will NOT Erase the device. To re-program the device you must disable Blank/Illegal Bit checks flags. To program the Hardware Write Protection option (WPEN) enable the "Program protect reg." flag. Performing a Load operation will also load the Status Register Protection Bits into the following address locations in User RAM: 25AA160 = Address $0800 25LC160 = Address $0800 25AA320 = Address $1000 25LC320 = Address $1000 25AA640 = Address $2000 25LC640 = Address $2000 The Status Register data format in the Programmer's User RAM will follow the same format as defined in the corresponding device's data sheet, as seen below: Status Register Format in relation to the Protection Bits: ------------------------------------------------------- |Bit 7 |Bit 6 |Bit 5 |Bit 4 |Bit 3 |Bit 2 |Bit 1 |Bit 0 | |-------------------------------------------------------| | WPEN | X | X | X | BP1 | BP0 | X | X | ------------------------------------------------------- Please refer the manufacturers data sheet for more details. NOTE: Checksum issues under TaskLink: Performing a LOAD DEVICE operation under TaskLink may produce a Checksum that does NOT match the checksum produced during any other device operations. To make sure Checksums match for all operations please enable "Use Algorithm Checksum." *********************************************************************** ************************************************************************