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CHAPTER 24 512K-BIT FLASH MEMORY
24.5 Starting the Flash Memory Automatic Algorithm
Three types of commands are available for starting the flash memory automatic
algorithm: Read/Reset, Write, and Chip Erase.
■ Command Sequence Table
Table 24.5-1 lists the commands used for flash memory write/erase. All of the data written to the command
register is in bytes, but use word access to write. The data of the high-order bytes at this time is ignored.
Table 24.5-1 Command Sequence Table
Command
sequence
Bus
write
access
1st bus write
cycle
2nd bus write
cycle
3rd bus write
cycle
4th bus write
cycle
5th bus write
cycle
6th bus write
cycle
Address
Data
Address
Data
Address
Data
Address
Data
Address
Data
Address
Data
Read/
reset*
1
FFXXXX XXF0 - - - - - - - - - -
Read/
reset*
4
FFAAAA XXAA FF5554 XX55 FFAAAA XXF0 RA RD - - - -
Write
program
4
FFAAAA XXAA FF5554 XX55 FFAAAA XXA0 PA
(even)
PD
(word)
--- -
Chip erase 6
FFAAAA XXAA FF5554 XX55 FFAAAA XX80 FFAAAA XXAA FF5554 XX55 FFAAAA XX10
Notes:• Addresses in the table are the values in the CPU memory map. All addresses and data are hexadecimal values, where
"x" is any value.
• RA: Read address
• PA: Program address. Only even addresses can be specified.
• RD: Read data
• PD: Program data. Only word data can be specified.
*: Two kinds of read/reset commands can reset flash memory to the read mode.