Datasheet

5 - INTERNAL FLASH MEMORY ST10F269
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Example 3 Performing the Block Erase command
We assume that in the initialization phase the lowest 32K Bytes of Flash memory (sector 0) have been
mapped to segment 1.The registers R11/R12 contain an address related to the block to be erased
(segment number in R11, segment offset in R12, for example R11 = 01h, R12= 4000h will erase the block
1 - first 8K byte block).
MOV R5, #01554h ;load auxilary register R5 with command address
;(used in command cycle 1)
MOV R6, #02AA8h ;load auxilary register R6 with command address
;(used in command cycle 2)
SXCT DPPO, #08h ;push data page pointer 0 and load it to point ;to
;segment 2
MOV R7, #0A8h ;load register R7 with 1st CI enable command
MOV [R5], R7 ;command cycle 1
MOV R7, #054h ;load register R7 with 2cd CI enable command
MOV [R6], R7 ;command cycle 2
MOV R7, #080h ;load register R7 with Block Erase command
MOV [R5], R7 ;command cycle 3
MOV R7, #0A8h ;load register R7 with 1st CI enable command
MOV [R5], R7 ;command cycle 4
MOV R7, #054h ;load register R7 with 2cd CI enable command
MOV [R6], R7 ;command cycle 5
POP DPP0 ;restore DPP0: following addressing to the Flash
;will use EXTended instructions
;R11 contains the segment of the block to be erased
;R12 contains the segment offset address of the
;block to be erased
MOV R7, #030h ;load register R7 with erase confirm code
EXTS R11, #1 ;use EXTended addressing for next MOV instruction
MOV [R12], R7 ;command cycle 6: the EPC starts execution of
;Erasing Command
Erase_Polling:
EXTS R11, #1 ;use EXTended addressing for next MOV instruction
MOV R7, [R12] ;read Flash Status register (FSB) in R7
;Check if FSB.7 = ‘1’ (i.e. R7.7 = ‘1’)
JB R7.7, Erase_OK
;Check if FSB.5 = 1 (Erasing Error)
JNB R7.5, Erase_Polling
;Programming failed: Flash remains in Write
;Operation.
;To go back to normal Read operations, a Read/Reset
;command
;must be performed
Erase_Error:
MOV R7, #0F0h ;load register R7 with Read/Reset command
EXTS R11, #1 ;use EXTended addressing for next MOV instruction
MOV [R12], R7 ;address is don’t care for Read/Reset command
... ;here place specific Error handling code
...
...
;When erasing operation finished succesfully,
;Flash is set back automatically to normal Read Mode
Erase_OK:
....