Fujitsu FR81S 用户手册
CHAPTER 45: FLASH MEMORY
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : FLASH MEMORY
FUJITSU SEMICONDUCTOR CONFIDENTIAL
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[bit3] SETI : Sector erase timer flag bit
During sector erase, a timeout period of 40μs is required from when the sector erase command is issued
until the sector erase actually starts. When the hardware sequence flag is read by specifying an arbitrary
address, this bit indicates whether or not the sector erase command is within the timeout period. The value
that is read differs depending on the state.
When erasing sectors:
When erasing sectors, you can check whether the next sector erase code is ready to be accepted by checking
this bit before inputting the next sector erase code. Reads out the next value without accessing the address
specified for reading the hardware sequence flag.
"0"
Within sector erase wait period (the next sector erase code (0x30) can be
accepted.)
"1"
When exceeding the sector erase wait period (if the DPOLL bit and
TOGG1 bit indicate that the automatic algorithm is executing at this
time, the flash memory internal erase is started. In this case, commands
other than the sector erase code (0x30) are ignored until the flash
memory internal erase finishes.)
[bit2] TOGG2 : Toggle flag 2 bit
In the sector erase suspend state, non target sector for erase can be read (read), but the target sector for erase
cannot be read. This flag indicates that output data is toggled and the target sector for erase when read
address is the target sector for erase during sector erase suspend.
Read out target erase sector
If this bit is read sequentially, "1" and "0" are read alternatively (toggle
operation). The address specified for reading the hardware sequence flag
is not accessed.
Read out non target erase
sector
Read data from specified address
[bit1,bit0] Undefined bits
MB91520 Series
MN705-00010-1v0-E
1957