Fujitsu MB90335 Series Hardware Manual page 508

MB90335 Series
■ Flash Memory Write Control Register (FWR0/FWR1) 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/FWR1) to "1" and "0", respectively.
Note that writes must be performed in words and bit manipulation instructions must not be used for setting.
Figure 22.3-5 Sample Procedure for Flash Memory Write-Enable/Protect Setting and Writing
Programming error
CM44-10137-6E
Start
FMCS: WE (bit5)
Programming enabled
FWR0/FWR1
Accidental write preventive function setting
(Accidental write preventive sector: 0,
writing sector
Program command sequence
(1)FFU AAA XXAA
H
(2)FFU554 XX55
H
(3)FFUAAA XXA0
H
(4)Program address
Internal address read
Data polling
(DQ7)
Data
0
Timing limit
(DQ5)
Internal address read
Data
Data polling
(DQ7)
Data
Last address
FMCS: WE (bit5)
Programming enabled
Completed
FUJITSU MICROELECTRONICS LIMITED
CHAPTER 22 DUAL OPERATION FLASH MEMORY
:1 )
H
H
H
Program data
Data
1
NO
YES
22.3 Registers of Flash Memory
Next address
487