Data Erase From Flash Memory (Chip Erase) - Fujitsu MB90335 Series Hardware Manual

MB90335 Series
22.7.3

Data Erase from Flash Memory (Chip Erase)

This section explains the procedure for inputting the chip erase command to erase all
data from flash memory.
■ All Data Erase from Flash Memory (Chip Erase)
• All data can be erased from flash memory by continuously transmitting the chip erase command in the
command sequence table from CPU to flash memory.
• The chip erase command is executed in six bus operations. Chip erasing is started at completion of the
sixth programming cycle.
• Before chip erasing, the user need not perform programming to flash memory. During execution of the
automatic erasing algorithm, flash memory automatically programs "0" before erasing all cells.
■ Notes on Chip Erasure
• The chip erase command is accepted only when all sectors have been write-enabled. The chip erase
command is ignored when any of the sector write-enable/protect bits in the flash memory write control
register (FWR0/FWR1) contains "0" (write-protected or accidental write prevented status).
• If the hardware reset is generated during erase operation, the data of flash memory is not guaranteed.
CM44-10137-6E FUJITSU MICROELECTRONICS LIMITED
CHAPTER 22 DUAL OPERATION FLASH MEMORY
22.7 Details of Programming/Erasing Flash Memory
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