Icw1: Edge/Level Mode, Single/Cascade Mode - Intel 80C188EC User Manual

Figure 8-11. 8259A Module Initialization Sequence
8.4.3.2

ICW1: Edge/Level Mode, Single/Cascade Mode

The bit positions and definitions for ICW1 are summarized in Figure 8-12.
Begin
Initialization
Write ICW1
Write ICW2
In
No
Cascade
Mode?
Yes
Write ICW3
No
Need
ICW4?
Yes
Write ICW4
Initialization
Complete
INTERRUPT CONTROL UNIT
A1219-0A
8-23