Datasheet

5–6

The following code in Figure 5–3 is an example of transmission of the single character s.

WDTCTL .equ 0120h

WDTHold .equ 80h

WDT_wrkey .equ 05a00h

TXCHAR .equ 0FFD2h

TXTABLE .equ 0FFD4h

PREPRX .equ 0FFD6h

PREPTX .equ 0FFD8h

INT_RXTX .equ 0FFDAh

TXDATA .equ 020Eh

RXBUF .equ 0210h

.text 0240h

RESET: MOV #03DEh,SP ; use #05DEh on the MSP430X33x

MOV #(WDTHold+WDT_wrkey),&WDTCTL ; stop Watchdog Timer

EINT ; enable interrupt

TX: MOV #0AA55h,&03DEh ; prepare software UART for the use

; in user application

(05DEh FOR MSP430X33x)

MOV.B #‘a’,&TXDATA ; put char to TXDATA

; BIC #01h,&200h ; use only if no special

; treatment of ESC is wanted

CALL &TXCHAR ; call transmit sub-routine in

; monitor

CALL &PREPRX ; prepare software UART for receive

; to get back to monitor with ESC

MOV #00h,&03DEh ; prepare software UART only for

; the use in the Hyperterminal

(05DEh FOR MSP430X33x)

ENDL: JMP ENDL

UART: BR &INT_RXTX

.sect “Int_Vect”,03E0h ; (use 05E0h on the MSP430X33x)

.word RESET ; Reset

.word UART ; UART Routine

.word RESET ; Reset

.end

Figure 5–3. Transmitting the s Character