95 lines
4.6 KiB
NASM
95 lines
4.6 KiB
NASM
;-------------------------------------------------------------------------------
|
|
; MSP430 Assembler Code Template for use with TI Code Composer Studio
|
|
;
|
|
;
|
|
;-------------------------------------------------------------------------------
|
|
.cdecls C,LIST,"msp430.h" ; Include device header file
|
|
|
|
;-------------------------------------------------------------------------------
|
|
.def RESET ; Export program entry-point to
|
|
; make it known to linker.
|
|
;-------------------------------------------------------------------------------
|
|
.text ; Assemble into program memory.
|
|
.retain ; Override ELF conditional linking
|
|
; and retain current section.
|
|
.retainrefs ; And retain any sections that have
|
|
; references to current section.
|
|
|
|
;-------------------------------------------------------------------------------
|
|
RESET mov.w #__STACK_END,SP ; Initialize stackpointer
|
|
StopWDT mov.w #WDTPW|WDTHOLD,&WDTCTL ; Stop watchdog timer
|
|
|
|
|
|
;-------------------------------------------------------------------------------
|
|
; Main loop here
|
|
;-------------------------------------------------------------------------------
|
|
Setup:
|
|
bis.b #004h, &P2DIR ; Set P2.2 to output
|
|
; direction (0000_0100)
|
|
bic.b #004h, &P2OUT ; Set P2OUT to 0x0000_0100 (ensure
|
|
; LED1 is off)
|
|
bis.b #002h, &P2DIR ; Set P2.1 to output
|
|
; direction (0000_0010)
|
|
bic.b #002h, &P2OUT ; Set P2OUT to 0x0000_0010 (ensure
|
|
; LED1 is off)
|
|
|
|
bis.w #GIE, SR ; Enable Global Interrupts
|
|
bis.b #001h, &P1IE ; Enable Port 1 interrupt from bit 0
|
|
bis.b #001h, &P1IES ; Set interrupt to call from hi to low
|
|
bic.b #001h, &P1IFG ; Clear interrupt flag
|
|
;mov.w #0, R8 ; Counter for inner loop
|
|
bic.b #0x04,&P2OUT ; Set P2OUT to 0x0000_0100 (LEDS off)
|
|
InfLoop: mov.w #0xFFFF, R5 ; Software delay (65,535*16cc/2^20 ~ 1s)
|
|
mov.w #0, R8 ; Counter for inner loop
|
|
Iter:
|
|
SWDelay1: nop ; 1cc (total delay is 16 cc)
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
dec.w R5 ; 1cc
|
|
jnz SWDelay1 ; 2cc
|
|
inc.b R8 ; 3cc
|
|
cmp #2, R8 ; 4cc
|
|
jnz Iter ; jump to Iter
|
|
xor.b #0x02, P2OUT ; toggle LED 2
|
|
jmp InfLoop ; goto InfLoop
|
|
|
|
SW1_ISR: bic.b #001h, &P1IFG ; Clear interrupt flag
|
|
ChkSw1: bit.b #01h, &P1IN ; Check if SW1 is pressed
|
|
; (0000_0001 on P1IN)
|
|
jnz LExit ; If not zero, SW is not pressed
|
|
; loop and check again
|
|
Debounce: mov.w #2000, R15 ; Set to (2000 * 10 cc )
|
|
SWD20ms: dec.w R15 ; Decrement R15
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
jnz SWD20ms ; Delay over?
|
|
bit.b #00000001b,&P1IN ; Verify SW1 is still pressed
|
|
jnz LExit ; If not, wait for SW1 press
|
|
LEDon: xor.b #0x04,P2OUT ; Turn on LED1
|
|
LExit: reti ; Return from interrupt
|
|
;-------------------------------------------------------------------------------
|
|
; Stack Pointer definition
|
|
;-------------------------------------------------------------------------------
|
|
.global __STACK_END
|
|
.sect .stack
|
|
;-------------------------------------------------------------------------------
|
|
; Interrupt Vectors
|
|
;-------------------------------------------------------------------------------
|
|
.sect ".reset" ; MSP430 RESET Vector
|
|
.short RESET
|
|
.sect ".int20" ;
|
|
.short SW1_ISR ; set SW1 Interupt service routine
|
|
.end
|