Texas Instruments MSP430x1xx User Manual

Page 436

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Flash Memory Access via JTAG and Software

C-24

C.5.3.2 Example: Programming One Word Into the Same Flash Memory Module via Software

The program execution waits after the write-to-flash instruction (MOV
#123h,&0FF1Eh) until the busy bit is reset again. If no other write-to-flash
instruction method is used the BUSY bit test may not be needed to ensure cor-
rect flash-write handling.

Lock = 0, WRT = 1

Write Data to Flash Address

Disable all interrupt sources

and Watchdog

Restore or Enable Required

Interrupt Sources and

Watchdog

Fxkey .set 03300h
Fwkey .set 0A500h

; No interrupt request may happen while the flash is programmed

MOV

#(Fwkey+WRT),&FCTL1: : Enable Write to flash

MOV

#123h,&0FF1Eh

: Write a word to flash

MOV

#Fwkey,&FCTL1

: Reset Write bit

XOR

#(Fxkey+Lock),&FCTL3

: Change Lock bit to 1

WRT = 0, Lock = 1

; Enable those interrupt sources that should be accepted