Information

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ZACWIRE
TM
DIGITAL OUTPUT
INCFS
Z
TIME_OUT,1 ;; INCREMENT TIME_OUT COUNTER
GOTO WAIT_PF
GOTO RTI ;; EDGE TIMEOUT OCCURRED
P_RISE: CLRF TIME_OUT ;; CLEAR THE EDGE TIME OUT
COUNTER
WAIT_PR: BTFSC PORTB,0 ;; WAIT FOR RISE OF PARITY
GOTO NEXT_BYTE
INCFS
Z
TIME_OUT,1 ;; INCREMENT EDGE TIME OUT
COUNTER
GOTO WAIT_PR
GOTO RTI ;; EDGE TIME OUT OCCURRED
NEXT_BYTE: INCF FSR,1 ;; INCREMENT THE INDF POINTER
MOVLW LAST_LOC
SUBWF FSR,0 ;; COMPARE FSR TO LAST_LOC
BTFSS STATUS,Z ;; IF EQUAL THEN DONE
GOTO WAIT_TLOW
IF HERE YOU ARE DONE READING THE ZAC WIRE AND HAVE THE DATA IN
TEMP_HIGH & TEMP_LOW
WAIT_TLOW: CLRF TIME_OUT
WAIT_TLF: TFSS PORTB,0 ; WAIT FOR FALL OF PORTB,0
INDICATING
GOTO GET_TLOW ; START OF TEMP LOW BYTE
INCFS
Z
TIME_OUT
GOTO WAIT_TLF
GOTO RTI ; EDGE TIMEOUT OCCURRED
RTI: TORE ANY STATE SAVED OFF AT
BEGINNING OF ISR
BCF INTCON,INTF ;; CLEAR INTERRUPT FLAG
BSF INTCON,INTE ;; ENSURE INTERRUPT RE-ENABLED
RETFI
E
;; RETURN FROM INTERRUPT