hi m using this program to make a frequency counter using pic16f628a and external interrupt is on pin rb0 . method m using is measuring time betwenn two rising pulses. one the rising edge comes i start the timer and on another i stop it .and then calculate the frequency.code is as shown below.
m not getting the correct timer values.
please let me know is my code correct?
m not getting the correct timer values.
Code:
;=====================================================================
; INTERRUPT SERVICE ROUTINE
;=====================================================================
OVFL_ISR
movwf TEMP ;Store the value of w temporarily
btfss INTCON, INTF ;check if it's a external interrupt or not!
retfie ;else check other interuppt or return
bcf INTCON, INTF
MOVLW B'00000001'
XORWF T1CON, F
BTFSC T1CON, TMR1ON
RETFIE
MOVF TMR1H, W
MOVWF TIMER1_HIGH
MOVF TMR1L, W
MOVWF TIMER1_LOW
CLRF TMR1H
CLRF TMR1L
movfw TEMP
retfie
;=====================================================================please let me know is my code correct?