Intel 80C188EC User Manual page 258

;Now start the master initialization
MOV DX, MPICP0
XOR AH, AH
MOV AL, 10001B
OUT DX, AL
;Now set base interrupt type at 20H (Type 32) for the master module in ICW2.
;This creates a contiguous block for the interrupt control unit
;from type 20H to type 2FH.
MOV DX, MPICP1
MOV AL, 20H
OUT DX, AL
;Now program the master cascade configuration register in ICW3
MOV DX, MPICP1
MOV AL, 80H
OUT DX, AL
;ICW4 completes the initialization
MOV DX, MPICP1
MOV AL, 1B
OUT
;Initialization is now complete. we can unmask global interrupts.
STI
BOOT_ROM ENDS
Example 8-1. Initializing the Interrupt Control Unit (Continued)
DX, AL
INTERRUPT CONTROL UNIT
;ICW1 for the slave is accessed
;thru MPICP0
;Clear reserved bits
;Edge trigger, cascade mode,
;IC4 required
;ICW2 is accessed thru MPICP1
;Base type is 20H (Type 32)
;ICW3 is also thru MPICP1
;Slave module is always on IR7
;ICW4 is also thru MPICP1
;No special fully nested mode,
;no AEOI mode, factory test codes
;set correctly
8-49