1 Attachment(s)
Cannot reset Timer0 properly
I can't figure out what other flag I need to reset to use Timer0 a 2nd time.
Attachment 7792
Timer0 works for 50mS on the first keypress of the upper left button on the keypad. But it keeps on going on the second keypress.
Code:
@ __CONFIG _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
@ __CONFIG _CONFIG1H, _FOSC_HSPLL_HS_1H
@ __CONFIG _CONFIG2L, _PWRT_OFF_2L & _BOR_ON_2L & _BORV_1_2L & _VREGEN_ON_2L
@ __CONFIG _CONFIG2H, _WDT_OFF_2H
@ __CONFIG _CONFIG3H, _CCP2MX_ON_3H & _PBADEN_OFF_3H & _LPT1OSC_OFF_3H & _MCLRE_ON_3H
@ __CONFIG _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _ICPRT_OFF_4L & _XINST_OFF_4L
DEFINE OSC 48
ADCON1 = %00001111 ' A/D CONTROL REGISTER 1
' Bit 7-6 Unimplemented: Read as ‘0’
' Bit 5 VCFG1: Voltage Reference Configuration bit (VREF- source)
' 0 = VSS
' 1 = Vref- (AN2)
' Bit 4 VCFG0: Voltage Reference Configuration bit (VREF+ source)
' 0 = VSS
' 1 = Vref+ (AN3)
' Bit 3-0 PCFG3:PCFG0: A/D Port Configuration Control bits:
' 1111 = All digital
' 1110 = All digital, AN0 analog
' 1101 = All digital, AN0 & AN1 analog
INTCON2 = %00000000 ' INTERRUPT CONTROL REGISTER 2
' Bit 7 RBPU: PORTB Pull-up Enable bit
' 1 = All PORTB pull-ups are disabled
' 0 = PORTB pull-ups are enabled provided that the pin is an input
' and the corresponding WPUB bit is set.
' Bit 6 INTEDG0: External Interrupt 0 Edge Select bit
' 1 = Interrupt on rising edge
' 0 = Interrupt on falling edge
' Bit 5 INTEDG1: External Interrupt 1 Edge Select bit
' 1 = Interrupt on rising edge
' 0 = Interrupt on falling edge
' Bit 4 INTEDG2: External Interrupt 2 Edge Select bit
' 1 = Interrupt on rising edge
' 0 = Interrupt on falling edge
' Bit 3 Unimplemented: Read as ‘0’
' Bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit
' 1 = High priority
' 0 = Low priority
' Bit 1 Unimplemented: Read as ‘0’
' Bit 0 RBIP: RB Port Change Interrupt Priority bit
' 1 = High priority
' 0 = Low priority
T0CON = %10000011 ' TIMER0 CONTROL REGISTER
' Bit 7 TMR0ON: Timer0 On/Off Control bit
' 1 = Enables Timer0
' 0 = Stops Timer0
' Bit 6 T08BIT: Timer0 8-Bit/16-Bit Control bit
' 1 = Timer0 is configured as an 8-bit timer/counter
' 0 = Timer0 is configured as a 16-bit timer/counter
' Bit 5 T0CS: Timer0 Clock Source Select bit
' 1 = Transition on T0CKI pin
' 0 = Internal instruction cycle clock (CLKO)
' Bit 4 T0SE: Timer0 Source Edge Select bit
' 1 = Increment on high-to-low transition on T0CKI pin
' 0 = Increment on low-to-high transition on T0CKI pin
' Bit 3 PSA: Timer0 Prescaler Assignment bit
' 1 = Timer0 prescaler is NOT assigned. Timer0 clock input
' bypasses prescaler.
' 0 = Timer0 prescaler is assigned. Timer0 clock input comes from
' prescaler output.
' Bit 2-0 T0PS2:T0PS0: Timer0 Prescaler Select bits
' 111 = 1:256 Prescale value
' 110 = 1:128 Prescale value
' 101 = 1:64 Prescale value
' 100 = 1:32 Prescale value
' 011 = 1:16 Prescale value
' 010 = 1:8 Prescale value
' 001 = 1:4 Prescale value
' 000 = 1:2 Prescale value
INCLUDE "DT_INTS-18.bas" ' Base Interrupt System
INCLUDE "ReEnterPBP-18.bas" ' Include if using PBP interrupts
ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
INT_Handler TMR0_INT, _EndTimer, PBP, no
endm
INT_CREATE ; Creates the interrupt processor
ENDASM
TRISA = %00000000
TRISB = %11110000 ' Set columns to input, rows to output
TRISC = %00000000
TRISD = %00000000
TRISE = %00000000
TimerLed VAR PORTD.1
LOW TimerLed
GOTO Main
StartTimer:
TMR0H = 109 ' 50 mS Timer
TMR0L = 144
INTCON.2 = 0
HIGH TimerLed
@ INT_ENABLE TMR0_INT ; enable Timer 0 interrupts
RETURN
EndTimer:
LOW TimerLed
RETURN
KeypadInput:
PORTB = %00001110 ' Row 1
IF PORTB.4 = 0 THEN ' Column 1
GOSUB StartTimer
WHILE PORTB.4 = 0: WEND
ENDIF
RETURN
Main:
GOSUB KeypadInput ' Scan 4 x 4 keypad
' Future logic goes here.
GOTO Main
END
(my first attempt at resetting the interrupt flag myself)
Robert
PIC 18F4550
Lab X1 board
PBP v2.60c
MPASM v5.46
Re: Cannot reset Timer0 properly
Hi Robert,
I see two problems.
1) The interrupt service routine ends with a RETURN, it really needs to end with an @ INT_RETURN
2) In the interrupt "declaration" you have the Clear Flag option set to no so DT-INTS will not clear the flag. Are you saying that you want to do it yourself? In that case you need to do it in the interrupt service routine.
/Henrik.
Re: Cannot reset Timer0 properly
Right on Henrik.
I came up with the same items. Had just converted the code to work on my HW and was testing.
These suggested changes seem to work here on my setup Robert.
1 Attachment(s)
Re: Cannot reset Timer0 properly
I hate outsmarting myself. I intentionally replaced that RETURN, argh...
I had also replaced the YES flag. I should have stepped away and taken a break, to take a different look at my code a few minutes later. I somehow thought more was going on and had to handle the flag myself, I obviously didn't. The interrupt won't take off again unless I call Start.
Code:
@ __CONFIG _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
@ __CONFIG _CONFIG1H, _FOSC_HSPLL_HS_1H
@ __CONFIG _CONFIG2L, _PWRT_OFF_2L & _BOR_ON_2L & _BORV_1_2L & _VREGEN_ON_2L
@ __CONFIG _CONFIG2H, _WDT_OFF_2H
@ __CONFIG _CONFIG3H, _CCP2MX_ON_3H & _PBADEN_OFF_3H & _LPT1OSC_OFF_3H & _MCLRE_ON_3H
@ __CONFIG _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _ICPRT_OFF_4L & _XINST_OFF_4L
DEFINE OSC 48
ADCON1 = %00001111 ' A/D CONTROL REGISTER 1
' Bit 7-6 Unimplemented: Read as ‘0’
' Bit 5 VCFG1: Voltage Reference Configuration bit (VREF- source)
' 0 = VSS
' 1 = Vref- (AN2)
' Bit 4 VCFG0: Voltage Reference Configuration bit (VREF+ source)
' 0 = VSS
' 1 = Vref+ (AN3)
' Bit 3-0 PCFG3:PCFG0: A/D Port Configuration Control bits:
' 1111 = All digital
' 1110 = All digital, AN0 analog
' 1101 = All digital, AN0 & AN1 analog
INTCON2 = %00000000 ' INTERRUPT CONTROL REGISTER 2
' Bit 7 RBPU: PORTB Pull-up Enable bit
' 1 = All PORTB pull-ups are disabled
' 0 = PORTB pull-ups are enabled provided that the pin is an input
' and the corresponding WPUB bit is set.
' Bit 6 INTEDG0: External Interrupt 0 Edge Select bit
' 1 = Interrupt on rising edge
' 0 = Interrupt on falling edge
' Bit 5 INTEDG1: External Interrupt 1 Edge Select bit
' 1 = Interrupt on rising edge
' 0 = Interrupt on falling edge
' Bit 4 INTEDG2: External Interrupt 2 Edge Select bit
' 1 = Interrupt on rising edge
' 0 = Interrupt on falling edge
' Bit 3 Unimplemented: Read as ‘0’
' Bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit
' 1 = High priority
' 0 = Low priority
' Bit 1 Unimplemented: Read as ‘0’
' Bit 0 RBIP: RB Port Change Interrupt Priority bit
' 1 = High priority
' 0 = Low priority
T0CON = %10000011 ' TIMER0 CONTROL REGISTER
' Bit 7 TMR0ON: Timer0 On/Off Control bit
' 1 = Enables Timer0
' 0 = Stops Timer0
' Bit 6 T08BIT: Timer0 8-Bit/16-Bit Control bit
' 1 = Timer0 is configured as an 8-bit timer/counter
' 0 = Timer0 is configured as a 16-bit timer/counter
' Bit 5 T0CS: Timer0 Clock Source Select bit
' 1 = Transition on T0CKI pin
' 0 = Internal instruction cycle clock (CLKO)
' Bit 4 T0SE: Timer0 Source Edge Select bit
' 1 = Increment on high-to-low transition on T0CKI pin
' 0 = Increment on low-to-high transition on T0CKI pin
' Bit 3 PSA: Timer0 Prescaler Assignment bit
' 1 = Timer0 prescaler is NOT assigned. Timer0 clock input
' bypasses prescaler.
' 0 = Timer0 prescaler is assigned. Timer0 clock input comes from
' prescaler output.
' Bit 2-0 T0PS2:T0PS0: Timer0 Prescaler Select bits
' 111 = 1:256 Prescale value
' 110 = 1:128 Prescale value
' 101 = 1:64 Prescale value
' 100 = 1:32 Prescale value
' 011 = 1:16 Prescale value
' 010 = 1:8 Prescale value
' 001 = 1:4 Prescale value
' 000 = 1:2 Prescale value
INCLUDE "DT_INTS-18.bas" ' Base Interrupt System
INCLUDE "ReEnterPBP-18.bas" ' Include if using PBP interrupts
ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
INT_Handler TMR0_INT, _EndTimer, PBP, yes
endm
INT_CREATE ; Creates the interrupt processor
ENDASM
TRISA = %00000000
TRISB = %11110000 ' Set columns to input, rows to output
TRISC = %00000000
TRISD = %00000000
TRISE = %00000000
TimerLed VAR PORTD.1
LOW TimerLed
GOTO Main
StartTimer:
TMR0H = 109 ' 50 mS Timer
TMR0L = 144
HIGH TimerLed
@ INT_ENABLE TMR0_INT ; enable Timer 0 interrupts
RETURN
EndTimer:
LOW TimerLed
@ INT_RETURN
KeypadInput:
PORTB = %00001110 ' Row 1
IF PORTB.4 = 0 THEN ' Column 1
GOSUB StartTimer
WHILE PORTB.4 = 0: WEND
ENDIF
RETURN
Main:
GOSUB KeypadInput ' Scan 4 x 4 keypad
' Future logic goes here.
GOTO Main
END
Attachment 7793
Eeesh, thanks guys! It works perfectly now.
Robert
