Intel MCS48 User Manual page 325

8255A/8255A-5
INTERRUPT
^
REQUEST
I
MODE
(OUTPUT)
825SA
BIT
SET/RESET
MODE
(INPUT)
PA
PA
1
PA
2
PA
3
PA
4
PA
5
PA
6
PA
7
PC
4
PC
5
PC
6
[pc
7
r
P
c
PC,
PC
2
p
c
3
~~
PB
PB,
PB
2
PB
3
PB
4
PB
5
PB
6
PB
7
LSB
12-BIT
DA
CONVERTER
(DAC)
MSB
STB
DATA
OUTPUT
EN
ANALOG OUTPUT
p
c
3
MODE
2
-
8255A
MODE
(OUTPUT)
~PA
PA,
PA
2
PA
3
PA
4
PA
6
PA
6
PA
7
PC
4
PC
7
^
PC
6
PC
2
p c
PC,
PB
PBl
PB
2
PB
3
PB
4
PB
5
P
B
6
PB
7
°0
°1
°2
D,
FLOPPY DISK
CONTROLLER
D
4
AND DRIVE
D
5
°6
°7
DATA
STB
ACK
(IN)
DATA READY
ACK
(OUT)
TRACK
"0"
SENSOR
SYNC
READY
INDEX
ENGAGE HEAD
FORWARD/REV.
READ ENABLE
WRITE ENABLE
DISC
SELECT
ENABLE CRC
TEST
BUSY LT
SAMPLE EN
STB
LSB
8-BIT
AD
CONVERTER
(ADC)
MSB
-«
ANALOG
INPUT
"
I"
Figure
20. Digital to
Analog, Analog to
Digital
Figure
22.
Basic Floppy Disc
Interface
INTERRUPT
REQUEST
'!"
PA
o
MODE
1
_j
(OUTPUT)
1
MODE
_
(OUTPUT)
INTERRUPT
REQUEST
CRT CONTROLLER
•
CHARACTER
GEN.
•
REFRESH BUFFER
•
CURSOR CONTROL
SHIFT
CONTROL
DATA READY
ACK
BLANKED
BLACK/WHITE
ROW
STB
COLUMN
STB
CURSOR H/V STB
CURSOR/ROW/COLUMN
ADDRESS
H&
V
MODE
1
(INPUT)
PA,,
PA
5
MODE
(INPUT)
MODE
(OUTPUT)
8
LEVEL
PAPER
TAPE
READER
ACK
STOP/GO
MACHINE TOOL
START/STOP
LIMIT
SENSOR
(HA/)
OUT OF
FLUID
CHANGE TOOL
LEFT/RIGHT
UP/DOWN
HOR. STEP
STROBE
VERT. STEP STROBE
SLEW/STEP
FLUID ENABLE
EMERGENCY
STOP
Figure
21.
Basic
CRT
Controller Interface Figure
23.
Machine Tool
Controller Interface
8-35
00744A