Arizona Picdem 17 用户手册

DS39024B-page 30

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 2001 Microchip Technology Inc.

; Branch to prolog

  movlw HIGH _T0CKI_prolog

  movwf PCLATH

  movlw LOW  _T0CKI_prolog

  movwf PCL

;-----------------------------------------------------------;

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

_PIV_sec  CODE  H’4020’

;-----------------------------------------------------------;

; Save ALUSTA

  movpf  ALUSTA, save_ALUSTA    ; must save ALUSTA before others

  movpf  WREG,   save_WREG      ; temporarily save off WREG

; Branch to prolog

  movlw HIGH _PIV_prolog

  movwf PCLATH

  movlw LOW  _PIV_prolog

  movwf PCL

;-----------------------------------------------------------;

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

InterruptCode   CODE

;-----------------------------------------------------------;

_INT_prolog

;Save BSR and WREG

  movfp  BSR, PCLATH

  clrf   BSR, 1

  movpf  PCLATH, save_BSR

;Service the interrupt by calling the interrupt

;handling function

  goto   _INT_2

_INT_1

  BANKSEL  fpINT

  movfp  fpINT+1, PCLATH

  movfp  fpINT, PCL

_INT_2

  call   _INT_1     ; push address of next instruction on stack

;Restore WREG and BSR

  clrf   BSR, 1              ;BSR was saved in bank 0

  movfp  save_BSR, BSR       ;Now restore it

  movfp  save_WREG, WREG     ;and WREG as well.

;Restore PCLATH and ALUSTA

  movfp  save_PCLATH, PCLATH

  movfp  save_ALUSTA, ALUSTA

;Return from interrupt

  RETFIE

;-----------------------------------------------------------;

;-----------------------------------------------------------;

_TMR0_prolog