I/O Command Decoder Truth Table - Omron 8025G Maintenance Manual

THEORY OF OPERATION SECTION 4
CPU
COMMAND
CODE
INPO
INPI
INP2
INP3
FROM
CPU
--..
MASTER
CLOCK
1311 MH,I
+5 V dc---.,.
Table
4-2.
I/O command decoder truth table.
INPUTS ACTIVE OUTPUTS
MA8
MAll - 13, WAIT, I/O
H
L
H
L
H
L
H
L
I/O
POLL. STAT. lOB. 100
COMMAND
~
DECODER
~
POWER
ON
CLEAR
HF
CLOCK
:2
+
RS
CLOCK
97"98
10 "4 NAVY
TO!232
Poe
OUT
fo
VIDEO
CONTRtL CARD
HORIZONTAL
FREQUENCY
:16&6
J
CHARACTER
" - ~
CLOCK
1O
+
"1.82
CLOCKS
•
r+-
•
" -
.......
....... 1
~
MAg
MAIO POLL
100
L
L L H
H L
H L
. .
L H H H
H H H
H
VSYNC HSYNC
TO
VIDEO
COMPOSITE
-.
2-CHARACTER
r--.
~~~SOR
SYNC
DELAY
COMPOSITE
BLANKING
CONTROL
t
,
CARDS
0.
HORIZONTAL
r-~
POSTIME BLANKING
INVERTER
GENERATOR
l
ROW
RATE
VERTICAL
~
CARRY
~
CLOCK
COUNTER
CLOCK
13
12
+
TO VIDEO CONTROL CARD
OTHER
TIMING
r-+
LOGIC
READ
CLOCK
Figure 4-9. Timing control card block diagram.
4-31
STAT lOB
--.
H H
H H
L H
H
L
TO
PROCESSOR.
REFRESH
BUFFER"
VIDEO CONTROL
CAR OS