[SOLVED] naken430asm some doubts

[vinodstanur]

How to write ISR in assembly?

I just wrote it as below but not working...Could any one help me?

.include "msp430g2x31.inc"
org 0xf800
start:
         mov #0x280,r1
         mov #23168,&WDTCTL
         mov #0xfee9, &TACTL
         mov.b #0xff,&P1DIR
         mov.b #0,&P1OUT
         eint
        mov.b #1,&P1OUT
gg:
        jmp gg

isr:
        xor.b #1,&P1OUT
        and #0xfffe,&TACTL
        reti              
        reti
org 0xfff0           ;timer_a2 vector
        dw isr
org 0xfffe           ;reset vector 
        dw 0xf800

 

[srizbf]

not working means?

assembles properly and generate hex file?
how did you test the working?

eint is in c.

---------- Post added at 16:32 ---------- Previous post was at 14:49 ----------

you are making P1 as 0.
then after eint (?)
why p1 as 1?.

a very short pulse in P1?
or you want make 1 in P1 after a time delay?
if that is so , no immediate P1 as 1.
only in isr.

and why there are two reti instn in isr?

 

[vinodstanur]

Yes I am getting the hex file properly,,

What I am trying to do is, just to toggle the P1.0 led in the MSP430 launchpad to toggle on every timer interrupt ...
I tried it without interrupt, by just polling the TACTL bit 0 (TAIFG) and that is working properly...That code is below...

THE BELOW CODE IS WORKING PROPERLY

.include "msp430g2x31.inc"
org 0xf800
start:
	 mov #0x280,r1              ;set stack pointer to just above the ram (0x27e)
	 mov #23168,&WDTCTL ;disabled watchdog timer
	 mov #0xfee9, &TACTL  ;set the TIMER control register 
	 mov.b #0xff,&P1DIR     ;set port1 as output
	 mov.b #0,&P1OUT        ;set port1 as zero
loop1:
	 mov #1,r8            
	 and &TACTL,r8	 	 ; moved TACTL bit 0 to r8 for comparing
	 cmp #1,r8                  ; checking to TACTL bit 0 is set 
	 jnz loop1                   ;if TACTL bit 0 (flag) not set, then go to loop1
	 xor.b #1,&P1OUT      ;toggle the LED
	 and #0xfffe, &TACTL ;just cleared the interrupt flag
 	 jmp loop1
org 0xfffe                           
	dw 0xf800                  ; set the reset vector start

Later I tried the first code I posted, there I tried to do it in the ISR but that is not working...I doubt the way I implemented the ISR. Is it right? I mean at least the SYNTAX ? Because I guessed the line

org 0xfff0           ;timer_a2 vector
        dw isr

by seeing the below code;

org 0xfffe           ;reset vector 
        dw 0xf800

I checked the interrupt vector address of timer in data sheet and found it as 0xfff0.
Also, I could see an instruction 'enti' from the datasheet (but not a core instruction).

 

[srizbf]

instead of two 'reti' , have only one 'reti' instruction. and try your first code.

 

[vinodstanur]

Tried that also...But still not working.........LED is always ON....

 

[vinodstanur]

Solved ;

I configured the TACTL incorrectly...Now I modified it as

mov.w #(TASSEL_2|MC_2|ID_3|TAIE), &TACTL

Now it is working...