Samsung F8274X Computer Hardware User Manual


 
EMBEDDED FLASH MEMORY INTERFACE S3F8275X
16-8
The Sector Erase Procedure in User Program Mode
1. Set Flash Memory User Programming Enable Register (FMUSR) to "10100101B".
2. Set Flash Memory Sector Address Register (FMSECH/FMSECL).
3. Check user’s ID code (written by user).
4. Set Flash Memory Control Register (FMCON) to "10100001B".
5. Set Flash Memory User Programming Enable Register (FMUSR) to "00000000B"
6. Check the "sector erase status bit" whether "sector erase" is success or not.
PROGRAMMING TIP Sector Erase
SB1
reErase: LD FMUSR,#0A5H ; User program mode enable
LD FMSECH,#10H
LD FMSECL,#00H ; Set sector address (1000H 107FH)
CP UserID_Code,#User_value ; Check user’s ID code (written by user)
; User_value is any value by user
JR NE,Not_ID_Code ; If not equal, jump to Not_ID_Code
LD FMCON,#10100001B ; Start sector erase
NOP ; Dummy instruction, this instruction must be needed
NOP ; Dummy instruction, this instruction must be needed
LD FMUSR,#0 ; User program mode disable
TM FMCON,#00001000B ; Check "Sector erase status bit"
JR NZ,reErase ; Jump to reErase if fail
Not_ID_Code:
SB1
LD FMUSR,#0 ; User Program mode disable