Fujitsu MB90895 Series Hardware Manual page 603

I Flash Memory Write Control Register (FWR0/1) Setting Flow
Set the FMCS:WE bit, then set the bits for sectors to write to and the bits for sectors to be
prevented from an accidental write in the flash memory write control register (FWR0/1) to "1" and
"0", respectively. Note that writes must be performed in words and bit manipulation instructions
must not be used for setting.
Figure 19.4-3 Sample Procedure for Flash Memory Write-Enable/Protect Setting and Writing
Programming error
Start
FMCS: WE (bit5)
Programming enabled
FFWR0/1
Accidental write preventive function setting
(Accidental write preventive sector: 0,
writing sector
Program command sequence
(1)FFUAAA XXAA
(2)FFU554 XX55
(3)FFUAAA XXA0
(4)Program address Program data
Internal address read
Data polling
(DQ7)
Data
0
Timing limit
(DQ5)
1
Internal address read
Data
Data polling
(DQ7)
Data
Last address
YES
FMCS: WE (bit5)
Programming enabled
Completed
CHAPTER 19 512 KBIT FLASH MEMORY
:1 )
Next address
Data
NO
585