Jeg har hentet dette program ned fra nettet for at lære bl.a. lidt mere om interupt timeren og lagring i ram området Desværre kan jeg ikke få programmet til at køre.
det ser ud som om der arbejdes med PortB en gang men så går programmet i stå ved med low på bit 3 og bit 4
Jeg håber der er nogen der kan fortælle mig hvorfor det går galt? ;****************************************************************** ;* A P P L I C A T I O N N O T E F O R T H E A V R F A M I L Y ;* ;* Number:AVR360 ;* File Name: "stepmot.asm" ;* Title :Simple high speed step motor controller ;* Date :98.07.02 ;* Version :1.00 ;* Support telephone :+47 72 88 43 88 (ATMEL Norway) ;* Support fax :+47 72 88 43 99 (ATMEL Norway) ;* Support E-mail : snipped-for-privacy@atmel.com ;* Target MCU :All AVR devices ;* ;*************************************************************** .include "8515def.inc"
;*************** Define global registers ************************ .def temp = R16
;*************** Define constants ****************************** .equ c_value = 500 ;Compare value for output compare interrupt ;500 cycles@5Mhz = 100us
;************************************************************* ;* ;* PROGRAM START - EXECUTION STARTS HERE ;* ;**************************************************************** .cseg
;Initialize interrupt vectors .org 0x00 rjmp main
.org OC1Aaddr ;Init Output compare A interrupt vector rjmp OC1A
;***************************************************************** ;* ;* OC1A- Timer1 Output compare A interrupt routine ;* ;* ;* DESCRIPTION ;* ;* This interrupt routine load new step motor value from the step ;* motor table in SRAM. The values in the table have two functions, ;* the lower nibble contains the value to output to the step motor. ;* The upper nibble holds the address of the next value. First the ;* step value is output to the port, next the address is moved to ;* the XL register. ;* ;* Number of words :6 + return ;* Number of cycles :7 + return ;* Low registers used :None ;* High registers used :3 (temp,XL,XH) ;*************************************************************** OC1A: in temp,SREG push temp ld temp,X ;Load temp with X pointer value mov XL,temp ;Move value to X pointer andi temp,0x0F ;Mask away upper nibble out PORTB,temp ;Output lower nibble to step motor swap XL ;Swap upper and lower nibble andi XL,0x0F ;Mask away upper nibble, address is ready pop temp out SREG,temp reti
;************************************************************* ;* ;* Main Program ;* ;* This program initialize Timer 1 output compare interrupt to ;* occur with a interval defined with the c_value constant. ;* The step motor lookup table is loaded from the flash and stored ;* in SRAM address 0x0100 to achieve maximum speed. ;* ;****************************************************************** main: ldi r16,high(RAMEND) ;Intialize stackpointer out SPH,r16 ldi r16,low(RAMEND) out SPL,r16 ldi temp,0x0F ;Set PORTB pin3-0 as output out DDRB,temp ldi temp,0x00 out PORTB,temp ;Write initial value to PORTB ldi temp,high(c_value) ;Load compare high value out OCR1AH,temp ldi temp,low(c_value) ;Load compare low value out OCR1AL,temp ldi temp,0x00 out TCNT1H,temp ;Clear timer high byte out TCNT1L,temp ;Clear timer low byte out TCCR1A,temp ;Clear timer control reg A ldi temp,0x40 out TIFR,temp ;Clear pending timer interrupt out TIMSK,temp ;Enable Timer compare interrupt ldi ZH,high(step*2) ;Init Z pointer to step table in flash ldi ZL,low(step*2) ldi XH,high(0x0100) ;Init X pointer to RAM location ldi XL,low(0x0100) ldi temp,0x04 ;Load counter value load: lpm ;Load step value from flash st X+,R0 ;Store step value in RAM adiw ZL,0x01 ;Increment flash pointer dec temp ;Decrement counter brne load ;Continue until table is loaded ldi XH,high(0x0100) ;Initialize X pointer to RAM location ldi XL,low(0x0100) ldi temp,0x9 out TCCR1B,temp ;Clear timer on compare match,CK/1 sei ;Enable global interrupt loop: rjmp loop ;Do something else
;*** Step motor lookup table *** step: .db 0x19,0x2C,0x36,0x03