Interrupt Initialization Command Words - NEC Advanced Personal Computer System Reference Manual

rrocessor rClJ
2-24
ICWI
07 06 OS 04 03
02 01
DO
/A7/A6/AS/1 /LTIM / AD! ISNGL I IC4 I
L
U
t
I: ICW4 NEEDED
0: NO ICW4 NEEDED
SET "I"
I: SINGLE
0: CASCADE
SET "0"
CALL ADDRESS INTERVAL
SET "0"
I: LEVEL TRIGGERED MODE
0: EDGE TRIGGERED MODE
SET"!"
INTERRUPT VECTOR ADDRESS
SET "0"
L-~~
_________________ INTERRUPTVECTORADDRESS
SET ALL "0"
L--L~--L--L------------------------INTERRUPTVECTORADDRESS
ICW3 (MASTER)
1 s71 s61 SSI S41 s31 s21 SI 1 SO
I
fL..--"fL-..Jt------' f ------' t ------' t ----Lt----Lf ________
l: IR INPUT HAS A SLAVE
0: IR INPUT DOES NOT HAVE A SLA VE
ICW3 (SLAVE)
SO TO S6
=
0, S7
=
1
102 101 100
tL.._--"t'------l.t ____
SLAVE ID
SET ALL TO
''I''
ICW4
I 0 I 0 I 0 I SFNM I BUF
MIS I AEOII tJ
PM I
~
1: 8086/8088 MODE
0: MCS-80/8S MODE
1: AUTO EOI
L---------
O : NORMALEOI
BUF MIS
L-________________ 0 X NON-BUFFERED MODE
1 0 BUFFERED MODE/SLA VE
1 1 BUFFER MODE/MASTER
L--_______________________
I: SPECIAL FULLY NESTED MODE SELECTED
0: SPECIAL FULLY NESTED MODE NOT SELECTED
Figure 2-15 Interrupt Initialization Command Words