Debugging of INTERRUPT routine in MPLAB SIM

[BlackOps]

mplab sim interrupts

Hello, i am debugging simple program, which turns on/off led every period of time. eround 2 seconds. and i want to measure the exact delay when the LED is On or Off (by calculation on paper it is 2.031616 seconds)

i am doing it on PIC16F88 chip, and using MPLAB SIM for debugging.

but during debug, the cursor goes to the main program loop after the setup routine, and never jumps to interrupt... So, the debugger doesnt make interrupt event occur, how can i fully debug it with MPLAB SIM?

here is code:

;***********************************************************************************
;
;
;
;
;***********************************************************************************

#include <p16F88.inc>
	
__CONFIG	_CONFIG1, _CP_OFF & _CCP1_RB0 & _DEBUG_ON & _WRT_PROTECT_OFF & _CPD_OFF & _LVP_OFF & _BODEN_OFF & _MCLR_ON & _PWRTE_ON & _WDT_OFF & _INTRC_IO



RESET_ADDR		EQU	0x00		
ISR_ADDR		EQU	0x04 	
COMRAM_ADDR		EQU 0x70	

	CBLOCK COMRAM_ADDR
status_temp       		
w_temp            		
count						
	ENDC


	ORG RESET_ADDR

START
	goto	SETUP    	
	ORG		ISR_ADDR

;***********************************************************************************
; START OF THE INTERRUPT SERVICE ROUTINE
;***********************************************************************************
INTERRUPT
	movwf	w_temp       	
	swapf	STATUS, w    	
	movwf	status_temp;
	

	decfsz	count, f			
	goto	INTEXIT 
	movlw 	b'10000000'	
	xorwf 	PORTB,f	
	movlw 	0x1F					
	movwf	count
	
INTEXIT
	bcf INTCON, TMR0IF		

	swapf status_temp, w 
	movwf STATUS
	swapf w_temp, f		
	swapf w_temp, w
	
	retfie				
;***********************************************************************************
; END OF THE INTERRUPT SERVICE ROUTINE
;***********************************************************************************
		
;***********************************************************************************
; START OF THE SETUP ROUTINE (RUNS ONLY ONCE)
;***********************************************************************************	
SETUP	
	banksel	OPTION_REG
	movlw	0xc7
	movwf	OPTION_REG
	
	banksel	TRISB
	movlw	b'00000000'
	movwf	TRISB
	
	banksel PORTB
	clrf	PORTB
	
	banksel OSCCON 
	movlw 	b'01100000' ; should be 4 mhz 
	movwf 	OSCCON 
	
	banksel	TMR0
	clrf	TMR0
	
	banksel	INTCON
	clrf	INTCON
	
	movlw	0x1f
	movwf	count
	
	movlw	0xe0
	movwf	INTCON	
;***********************************************************************************
; END OF THE SETUP ROUTINE
;***********************************************************************************
	
	
;###################################################################################
; MAIN PROGRAM START
;###################################################################################	
MAINLOOP
	nop
	nop
	nop
	goto MAINLOOP
;###################################################################################
; MAIN PROGRAM END
;###################################################################################	
	
END

 

[andre_luis]

mplab sim logic analyzer

BlackOps,

Debuggers that are not JTAG, don't work with interrupts and assincronous events.

+++

 

[BlackOps]

mplab interrupts

what u mean abt Jtag debuggers? where to read about them? got links? about the ones which work with PIC microcontrollers...

 

[creative_35]

mplabsim tmr0

what crystel you are using?
if you want a 2.031616 second delay with the above routine, you have to use a crystel of 129.032 Mhz crystel wich is not possible with a pic.
your code will jump to interrupt routine exactly after tmr0 overflow and if you want to watch the exact time there is a stop watch in the debugmenu. open it and run the code. open debugger/settings/animation and set the animation speed as 1 msec so that it will run with an average speed.
Put a breakpoint in interrupt routine and run the code you will get exact time.

 

[BlackOps]

mplab sim

well i have remaked code a little, now it works fine.
creative_35 what are you talking about 129Mhz crystal??? why??? i am using just 4Mhz internal oscillator, and i get 2.031616 seconds as i see... because i did the simulation in PROTEUS and used its COUNTER tool, to count how many seconds LED will be on... it showed exactly this result. (the one thing is strange when program simulation began in proteus counter tool already had some little time on it...but when subtracted this time from the one i got after led is on, i got exactly 2.031616 secs)

here is the calculation, correct me if i am wrong:

1. 4mhz Oscillator, after divide by 4 is 1Mhz instruction clock

2. 1Mhz is divided in prescaler by 256, and the frequency fed to TMR0 register is 1Mhz/256 = 0.00390625 Mhz, so the TMR0 increments every 1/0.00390625Mhz = 256us

3. TMR0 has 256 possible values so it will interrupt every 256 * 256us = 65536us

4. count variable in setup routine is assigned value 31 (DEC), so interrupt routine decrements it and turns on/off led for: 31 * 65536us = 2.031616 seconds.

and as u c i used 4mhz crystal...not 129...

and the stopwatch which u was talking about just show me the increment by 1us every instruction cycle, after the setup routine it jumps to infinite looop in the main program loop, so the stop watch increments infinitely..


anyway thanks

Can anyone show or explain to me how to use Logic Analyser in MPLAB SIM, it doesnt seem to work...or show some diagramm? thanks

Added after 4 hours 47 minutes:

well, now i want to add some value to TMR0, to get another value.
for example, now i must get 0.7936 second delay

again comes the calculation:

DELAY = (4 * PRESCALER * (256 - TMR0) * count) / Crystal

if TMR0 will have 156 as initial value, then it will count 100 times. So:

DELAY = (4 * 256 * (256 - 156) * 31) / 4 000 000 = 0.7936 seconds

but when i tested its delay in PROTEUS i got: 0.777883 that is wrong, WHY? have any idea?

i also know that during the write to TMR0 it takes 2 instruction cycles, so i did this both in the SETUP routine and in the INTERRUPT:

movlw .158
movwf TMR0

so, where is the problem?

thanks

and plz can anybody answer to my previous post about Logic Analyzer??

 

[shyounessi]

mplab what interrupt

you can change its proper intruppt flag register manully
i think PIR1 register can be modified in View menu and so you can
intruppt program.

 

[creative_35]

debug interrupt mplab

well i have remaked code a little, now it works fine.
creative_35 what are you talking about 129Mhz crystal??? why??? i am using just 4Mhz internal oscillator, and i get 2.031616 seconds as i see... ??

Yes, you are right. I didn't notice your count variable. I just calculated the time to occur an interrupt. sorry.

 

[BlackOps]

mplab sim inerrupt goto start

I still cannot use the Logic Analyser in MPLAB SIM debugger! and cannot find any info on it, help files contain little information about it. did anyone use it? i add channels, then do run. then open logic analyser window, and dont see any graphs! help me plz with this!

Added after 57 minutes:

well i have changed this program to get EXACT 1 second delay! but it doesnt work correct... here is source code:

;***********************************************************************************
;
;
;
;
;***********************************************************************************

#include <p16F88.inc>
	
__CONFIG	_CONFIG1, _CP_OFF & _CCP1_RB0 & _DEBUG_ON & _WRT_PROTECT_OFF & _CPD_OFF & _LVP_OFF & _BODEN_OFF & _MCLR_ON & _PWRTE_ON & _WDT_OFF & _INTRC_IO



RESET_ADDR		EQU	0x00		
ISR_ADDR		EQU	0x04 	
COMRAM_ADDR		EQU 0x70	

	CBLOCK COMRAM_ADDR
status_temp       		
w_temp            		
count						
	ENDC


	ORG RESET_ADDR

START
	goto	SETUP    	
	ORG		ISR_ADDR

;***********************************************************************************
; START OF THE INTERRUPT SERVICE ROUTINE
;***********************************************************************************
INTERRUPT



	movwf	w_temp       	
	swapf	STATUS, w    	
	movwf	status_temp;
	

	decfsz	count, f			
	goto	INTEXIT 
	movlw 	b'10000000'	
	xorwf 	PORTB,f	
	movlw 	.5000					
	movwf	count
	movlw	.158
	movwf	TMR0	

	
INTEXIT

	bcf INTCON, TMR0IF		

	swapf status_temp, w 
	movwf STATUS
	swapf w_temp, f		
	swapf w_temp, w
	

	
	retfie				
;***********************************************************************************
; END OF THE INTERRUPT SERVICE ROUTINE
;***********************************************************************************
		
;***********************************************************************************
; START OF THE SETUP ROUTINE (RUNS ONLY ONCE)
;***********************************************************************************	
SETUP	
	banksel	OPTION_REG
;	movlw	0xc7
	movlw	0xc0
	movwf	OPTION_REG
	
	banksel	TRISB
	movlw	b'00000000'
	movwf	TRISB
	
	banksel PORTB
	clrf	PORTB
	
	banksel OSCCON 
	movlw 	b'01100000' ; should be 4 mhz 
	movwf 	OSCCON 

	banksel	INTCON
	clrf	INTCON
	
	movlw	.5000
	movwf	count
	
	movlw	0xe0
	movwf	INTCON	
	
	movlw	.158
	movwf	TMR0
;***********************************************************************************
; END OF THE SETUP ROUTINE
;***********************************************************************************
	
	
;###################################################################################
; MAIN PROGRAM START
;###################################################################################	
MAINLOOP
	nop
	nop
	nop
	goto MAINLOOP
;###################################################################################
; MAIN PROGRAM END
;###################################################################################	
	
END

from calculation i must get:

1 second = (4 * 2 * 100 * 5000) / 4 000 000

but program doesnt work normal....i dont get 1sec delay, what is problem?
and please help me to use normally logic analyzer in MPLAB SIM