User manual

Appendix D Register-Level Programming
© National Instruments Corporation D-29 PC-DIO-96/PnP User Manual
decrementing all references to the base page register, bp, by two in
install_isr() and remove_isr() only. Do not modify
isr_handler().
; assemble this file with the following command:
; masm /MX filename;
; /MX preserves case sensitivity
;
;
; function prototypes:
;
; void install_isr(int level, isr_block_type far * isr_block);
;
; on input, level indicates the interrupt level that is to be modified
; on input, isr_block points to the data structure that will be used by
; the isr_handler function
;
; void isr_handler(void);
;
; the isr_handler() function will never be called from C.....
;
; void remove_isr(void);
;
public _install_isr, _isr_handler, _remove_isr
_DATA segment word public 'DATA'
; declarations
ackm equ 00020h
acks equ 000a0h
eoi equ 00020h
maskm equ 00021h
masks equ 000a1h
int_addr dd 0
int_mask dw 0
isrb_addr dd 0
slave_ack db 0
vect_num db 0
_DATA ends