Key Differences Between Block Protect Schemes of Excelon Ultra QSPI F-RAM and SPI F-RAM – KBA221693

Version 2

    Version: *A

     

    Translation - Japanese: Excelon Ultra QSPI F-RAMとSPI F-RAMのブロック保護スキームの主な違い –  KBA221693- Community Translated (JA)

     

    Question:

    What are the key differences between the block protect schemes of Excelon™ Ultra QSPI F-RAM™ and SPI F-RAM?

     

    Answer:

    The Block Protect scheme is a way of protecting a section of the memory from write, which helps prevent unwanted/ accidental writes. The Excelon Ultra QSPI F-RAM Block Protect bits (BP2, BP1, BP0) in combination with the Top or Bottom Protection (TBPROT) bit can be used to protect an address range of the Excelon Ultra QSPI F-RAM array. The TBPROT bit controls the starting address of the memory array (either from top or bottom) that gets protected by the Block Protection bits. The TBPROT feature is not available in SPI F-RAMs.

     

    • If TBPROT = 1, protection starts at the first location form the bottom
    • If TBPROT = 0, protection starts at the first location form the top

     

    You can protect down to 1/64th of the memory array. The following is the combination of Block Protect bits protecting a section of the 4Mb QSPI F-RAM:

     

    Start of Protection from Top (TBPROT = 0)

    Start of Protection from Bottom (TBPROT = 1)

    In SPI F-RAM, there are two Block Protect bits (BP1 and BP0), which can protect down to 1/4th of the memory array. The following is the memory protection table for the 4Mb SPI F-RAM device. The protected memory address range varies with density and is provided in respective device datasheets.

     

    Block Memory Write Protection: