Operation Control Word (Ocw) Formats - Advanced Micro Computers Am96/4116A User Manual

oew,
I/O AooR:
FFCAH
,----------------
L__
Interrupt Mask Bits
, =
Masked (Inhibited)
o
=
Enabled
A, D7 06 D5 04 03 02 01 DO
OeW2
~,..L----r--..I-JSEOiI~F;OI
0
~~
I/O AOOR:
FFC8H
0 (I
20H Non-Specific EOI LO-L2
=
0
0
1
60 to 67H Specific EOI LO-L2
=
Code of IS
FIF to be reset
(I
AOH Rotate at EOI Automatically (Mode A)
1
EO to E7H Rotate at EOI (Mode B), LO-L2
Code of Line
,
(I 0 BOH
Set Rotate A FIF, LO-L2
=
0
0 (I 0
OOH Clear Rotate A FIF, LO-L2
=
0
, ,
0 COH Rotate Priority (Mode B)
Independent of EOI.
OCW3
I/O AOOR:
FFG8H
02 01 DO
P
I
ERIS
I
RIS
I
Don't
Care
o
o
o
1
No
Action
o
Read IR Reg on Next
RD Pulse
Read IS Reg on Next
RD Pulse
o
o
o
,
No
Action
, =
Polling Mode
o
=
Interrupt Mode
o
Reset Special Mask
1 Set Special Mask
...... _"---'------,----
Figure 3-10. Operation Control Word (OCW) Formats
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