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CHAPTER 28 3M-BIT FLASH MEMORY
28.7.4
Erasing Optional Data (Erasing Sectors)
This section describes the procedure for issuing the Sector Erase command to erase
optional data (erase sector) in the flash memory. Individual sectors can be erased.
Multiple sectors can also be specified at one time.
■
Erasing Optional Data (Erasing Sectors) in the Flash Memory
Optional sectors in the flash memory can be erased by sending the Sector Erase command in the command
sequence table (see Table 28.5-1 in Section "28.5 Starting the Flash Memory Automatic Algorithm")
continuously to the target sector in the flash memory.
●
Specifying sectors
The Sector Erase command is executed in six bus operations. Sector erase wait of 50
μ
s is started by writing
the sector erase code (30
H
) to an accessible even-numbered address in the target sector in the sixth cycle.
To erase multiple sectors, write the erase code (30
H
) to the addresses in the target sectors after the above
processing operation.
●
Notes on specifying multiple sectors
Erase is started when the sector erase wait period of 50
μ
s terminates after the final sector erase code has
been written. That is, to erase multiple sectors at one time, an erase code (sixth cycle of the command
sequence) must be written within 50
μ
s of writing of the address of a sector and the address of the next
sector must be written within 50
μ
s of writing of the previous erase code. Otherwise, the address and erase
code may not be accepted. The sector erase timer (hardware sequence flag DQ3) can be used to check
whether writing of the subsequent sector erase code is valid. At this time, specify so that the address used
for reading the sector erase timer indicates the sector to be erased.
■
Erasing Sectors in the Flash Memory
The hardware sequence flags (see Section "28.6 Confirming the Automatic Algorithm Execution State")
can be used to determine the state of the automatic algorithm in the flash memory. Figure 28.7-2 shows the
example of the flash memory sector erase procedure. Here, the toggle bit flag (DQ6) is used to confirm that
erasing has terminated.
The data that is read to check the flag is read from the sector to be erased.
The toggle bit flag (DQ6) stops the toggle operation at the same time that the timing limit exceeded flag
(DQ5) is changed to "1". For example, even if the timing limit exceeded flag (DQ5) is "1", the toggle bit
flag (DQ6) must be rechecked.
The data polling flag (DQ7) also changes at the same time that the timing limit exceeded flag bit (DQ5)
changes. As a result, the data polling flag (DQ7) must be rechecked.
Содержание MB90390 Series
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Страница 17: ...xiii APPENDIX D List of Interrupt Vectors 690 INDEX 695 ...
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Страница 132: ...104 CHAPTER 5 CLOCKS ...
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Страница 210: ...182 CHAPTER 11 TIME BASE TIMER ...
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Страница 264: ...236 CHAPTER 14 16 BIT RELOAD TIMER WITH EVENT COUNT FUNCTION ...
Страница 274: ...246 CHAPTER 15 WATCH TIMER ...
Страница 306: ...278 CHAPTER 17 DTP EXTERNAL INTERRUPTS ...
Страница 338: ...310 CHAPTER 18 8 10 BIT A D CONVERTER ...
Страница 364: ...336 CHAPTER 19 UART0 UART1 ...
Страница 398: ...370 CHAPTER 20 UART2 UART3 Figure 20 5 2 ORE Set Timing Receive data RDRF ORE ...
Страница 432: ...404 CHAPTER 20 UART2 UART3 ...
Страница 482: ...454 CHAPTER 22 SERIAL I O ...
Страница 560: ...532 CHAPTER 24 STEPPING MOTOR CONTROLLER ...
Страница 582: ...554 CHAPTER 27 ROM MIRRORING MODULE ...
Страница 632: ...604 CHAPTER 29 EXAMPLES OF SERIAL PROGRAMMING CONNECTION ...
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Страница 723: ...695 INDEX The index follows on the next page This is listed in alphabetic order ...
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