Interrupt RPM and Taylors Elapsed time on 18F4620

[Tobias]

Here is the elasped timer code I modified to use T3 and go to the thousandths. Also I have the interrupt set up as INTLHAND

'****************************************************************
'*  Name    : ELAPSED.PBP                                       *
'*  Author  : Darrel Taylor                                     *
'*  Notice  : Copyright (c) 2003                                *
'*  Date    : 12/16/2003                                        *
'*  Notes   :                                                   *
'****************************************************************
disable debug

Define  INTLHAND _ClockCount    ' Tell PBP Where the code starts on an interrupt
Include "ASM_INTS-18.bas"         ' ASM Interrupt Stubs

Ticks    var Word   ' 1/1000th of a second
Seconds  var byte
Minutes  var byte
Hours    var byte
Days     var word
R0save   var word
R1save   var word
R4save   var word

SecondsChanged   var bit
MinutesChanged   var bit
HoursChanged     var bit
DaysChanged      var bit
SecondsChanged = 1
MinutesChanged = 1

Goto OverElapsed

' ------------------------------------------------------------------------------
Asm
  IF OSC == 4                       ; Constants for 100hz interrupt from Timer1
TimerConst = 0D8F7h                 ; Executed at compile time only
  EndIF
  If OSC == 8
TimerConst = 0B1E7h
  EndIF
  If OSC == 10
TimerConst = 09E5Fh
  EndIF
  If OSC == 20
TimerConst = 0EC80h
  EndIF
  If OSC == 40
TimerConst = 03CB7h
  EndIF

; -----------------  ADD TimerConst to TMR1H:TMR1L
ADD2_TIMER   macro
    CHK?RP  T3CON
    BCF     T3CON,TMR3ON           ; Turn off timer
    MOVLW   LOW(TimerConst)        ;  1
    ADDWF   TMR3L,F                ;  1    ; reload timer with correct value
    BTFSC   STATUS,C               ;  1/2
    INCF    TMR3H,F                ;  1
    MOVLW   HIGH(TimerConst)       ;  1
    ADDWF   TMR3H,F                ;  1
    endm

; -----------------  ADD TimerConst to TMR1H:TMR1L and restart TIMER1
RELOAD_TIMER  macro
    ADD2_TIMER
    BSF     T3CON,TMR3ON           ;  1    ; Turn TIMER1 back on
    CHK?RP  PIR2
    bcf     PIR2, TMR3IF           ; Clear Timer1 Interrupt Flag
    endm

; -----------------  Load TimerConst into TMR1H:TMR1L
LOAD_TIMER  macro
EndAsm
    T3CON.0 = 0                    ; Turn OFF Timer1
    TMR3L = 0
    TMR3H = 0
Asm
    ADD2_TIMER
    endm
EndAsm

' ------[ This is the Interrupt Handler ]---------------------------------------
ClockCount:   ' Note: this is being handled as an ASM interrupt
@ INT_START
@ RELOAD_TIMER                    ; Reload TIMER1
  R0save = R0                     ; Save 2 PBP system vars that are used during
  R1save = R1                     ; the interrupt
  R4save = R4
    Ticks = Ticks + 1
    if Ticks = 1000 then
       Ticks = Ticks-1000
       Seconds = Seconds + 1
       SecondsChanged = 1
       if Seconds = 60 then
          Minutes = Minutes + 1
          MinutesChanged = 1
          Seconds = 0
       endif
       if Minutes = 60 then
          Hours = Hours + 1
          HoursChanged = 1
          Minutes = 0
       endif
       if Hours = 24 then
          Days = Days + 1
          DaysChanged = 1
          Hours = 0
       endif
    endif
  R4 = R4save                     ; Restore the PBP system vars
  R1 = R1save
  R0 = R0save
@ INT_RETURN                      ; Restore context and return from interrupt

'-----====[ END OF TMR1 Interrupt Handler ]====---------------------------------

StartTimer:
    T3CON.1 = 0                   ; (TMR1CS) Select FOSC/4 Clock Source
    T3CON.3 = 0                   ; (T1OSCEN) Disable External Oscillator
    PIR2.1  = 0                   ; (TMR1IF) Clear Timer1 Interrupt Flag
    PIE2.1  = 1                   ; (TMR1IE) Enable TMR1 overflow interrupt
    INTCON.6 = 1                  ; (PEIE) Enable peripheral interrupts
    INTCON.7 = 1                  ; (GIE) Enable global interrupts
    T3CON.0 = 1                   ; (TMR1ON) Start TIMER1
@ if OSC == 40
    T3CON.5 = 0                   ; Prescaler = 1:2
    T3CON.4 = 1
@ endif
return

; -----------------
StopTimer:
    T3CON.0 = 0                   ; Turn OFF Timer1
return

; -----------------
ResetTime:
    R0save = T3CON.0              ; Save TMR1ON bit
    T3CON.0 = 0                   ; Turn OFF Timer1
    TMR3L = 0
    TMR3H = 0
@   LOAD_TIMER                    ; Load TimerConst
    T3CON.0 = R0save              ; Restore TMR1ON bit
    Ticks = 0
    Seconds = 0
    Minutes = 0
    Hours = 0
    Days = 0
    SecondsChanged = 1
return

OverElapsed:
enable debug

[Tobias]

This appears to be working correctly. Are there any problems going this route?
Of course this isn't all the code, just the part that is relevant.

DEFINE INTHAND Direction 

ASM
Direction
ENDASM
  If PIR1.2 = 1 then
    goto RPMASM
  endif
  
  If PIR2.1 = 1 then
    goto ClockCount
  endif
return  

RPMASM: 
ASM
CCP_INT
  BTFSS CCP1CON,0      ; capture from rising edge?
  BRA Fall             ; no .. goto falling edge
  MOVFF CCPR1L, TS    ; get low capture byte into T1
  MOVFF CCPR1H, TS+1   ; get high capture byte into T1
  BRA IntExit          ; outta here
Fall
  MOVFF CCPR1L, PW     ; get low capture byte into PW
  MOVFF CCPR1H, PW+1   ; get high capture byte into PW
  BSF CF,0             ; indicate last capture
IntExit
  BTG CCP1CON,0        ; toggle between rising/falling edge captures
  BCF PIR1,2           ; clear capture interrupt flag bit
  RETFIE FAST          ; return/restore W, STATUS and BSR
ENDASM

ClockCount:   ' Note: this is being handled as an ASM interrupt
@ INT_START
@ RELOAD_TIMER                    ; Reload TIMER1
  R0save = R0                     ; Save 2 PBP system vars that are used during
  R1save = R1                     ; the interrupt
  R4save = R4
    Ticks = Ticks + 1
    if Ticks = 1000 then
       Ticks = Ticks-1000
       Seconds = Seconds + 1
       SecondsChanged = 1
       if Seconds = 60 then
          Minutes = Minutes + 1
          MinutesChanged = 1
          Seconds = 0
       endif
       if Minutes = 60 then
          Hours = Hours + 1
          HoursChanged = 1
          Minutes = 0
       endif
       if Hours = 24 then
          Days = Days + 1
          DaysChanged = 1
          Hours = 0
       endif
    endif
  R4 = R4save                     ; Restore the PBP system vars
  R1 = R1save
  R0 = R0save
@ INT_RETURN                      ; Restore context and return from interrupt

[Bruce]

You don't need the bit tests in Direction since you have CCP_INT (or Direction) set as a high-priority interrupt, and you have ClockCount set as a low-priority interrupt.

Direction will be jumped to automatically when the CCP interrupt fires. ClockCount will be jumped to automatically when the TMR3 interrupt fires. Note that your low-priority interrupt can be interrupted by the high-priority one.