PIC18F010T-I View Datasheet(PDF) - Microchip Technology
Part Name
Description
MFG CO.
'PIC18F010T-I' PDF : 176 Pages View PDF
PIC18F010/020
EXAMPLE 6-2: PROGRAM MEMORY WRITE
This example will buffer a segment of memory, modify one word in the buffer, erase the segment row, and write the buffer
back to memory.
MOVLW 32
; number of bytes in row
MOVWF COUNTER
MOVLW BUFFER_ADDR_HIGH ; point to buffer
MOVWF FSR0H
MOVLW BUFFER_ADDR_LOW ;
MOVWF FSR0L
MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base
MOVWF TBLPTRU
; address of the memory row
MOVLW CODE_ADDR_HIGH ;
MOVWF TBLPTRH
;
MOVLW CODE_ADDR_LOW ;
MOVWF TBLPTRL
;
READ_ROW
TBLRD*+
; read into TABLAT, and inc
MOVF TABLAT, W
; get data
MOVWF POSTINC0
; store data
DECFSZ COUNTER
; done?
GOTO READ_ROW
; repeat
MODIFY_WORD
MOVLW DATA_ADDR_HIGH ; point to buffer
MOVWF FSR0H
MOVLW DATA_ADDR_LOW ;
MOVWF FSR0L
MOVLW NEW_DATA_LOW ; update buffer word
MOVWF POSTINC0
MOVLW NEW_DATA_HIGH
MOVWF INDF0
ERASE_ROW
MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base
MOVWF TBLPTRU
; address of the memory row
MOVLW CODE_ADDR_HIGH ;
MOVWF TBLPTRH
;
MOVLW CODE_ADDR_LOW ;
MOVWF TBLPTRL
;
BSF
EECON1,WREN
; enable write to memory
BSF
EECON1,FREE
; Enable Row Erase operation
BSF
EECON1,EEPGD ; Point to FLASH program memory
MOVLW 55h
MOVWF EECON2
; write 55H
MOVLW AAh
MOVWF EECON2
; write AAH
BSF
EECON1,WR
; start erase (CPU stall)
WRITE_BUFFER_BACK
MOVLW 8
; number of write buffer groups of 4 bytes
MOVWF COUNTER_HI
MOVLW BUFFER_ADDR_HIGH ; point to buffer
MOVWF FSR0H
MOVLW BUFFER_ADDR_LOW ;
MOVWF FSR0L
TBLRD*-
; back the TBLPTR up one
PROGRAM_LOOP
MOVLW 4
; number of bytes in write buffer
MOVWF COUNTER
2001 Microchip Technology Inc.
Preliminary
DS41142A-page 51
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