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CHAPTER 33 FLASH MEMORY
33.7
Detailed Explanation of Writing to and Erasing Flash
Memory
This section describes each operation procedure of flash memory Read/Reset, Write,
Chip Erase, Sector Erase, Sector Erase Suspend, and Sector Erase Restart when a
command that starts the automatic algorithm is issued.
■ Detailed explanation of flash memory write/erase
By issuing a command sequence (see Table 33.5-1 Command sequence table in Section 33.5 Starting the
Flash Memory Automatic Algorithm) the flash memory executes the automatic algorithm to perform Read/
Reset, Write, Chip Erase, Sector Erase, Sector Erase Suspend, or Sector Erase Restart operations.
In between write accesses of the command sequence, other bus read/write cycles can be performed as long
as no write access to the flash memory other than defined by the command sequence is performed.
Termination of the automatic algorithm can be determined by polling the toggle flags, polling the
MFMCS:RDY/SFMCS:RDY flag or by interrupt. At normal termination, the flash memory returns to the
read/reset state.
Each operation of the flash memory is described in the following order:
•
Setting the read/reset state
•
Writing data
•
Erasing all data (erasing chips)
•
Erasing optional data (erasing sectors)
•
Suspending sector erase
•
Restarting sector erase
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