HS1-82C55ARH-8 Intersil, HS1-82C55ARH-8 Datasheet - Page 7

• Manufacturer Part Number: HS1-82C55ARH-8
• Manufacturer: Intersil

Specifications of HS1-82C55ARH-8

• Operating Temperature (max): 125C
• Mounting: Through Hole
• Lead Free Status / RoHS Status: Compliant

Port C
Operational Description
Control Word
The data direction and mode of Ports A, B and C are
determined by the contents of the Control Word. See
Figure 11. The Control Word can be both written and read as
shown in Table 1 and 2. During write operations, the function
of the Control Word being written is determined by data bit
D7. If D7 is low, the data on D0 - D3 will set or reset one of
the bits of Port C. See Figure 12. During read Operations,
the Control Word will always be in the format illustrated in
Figure 11 with Bit D7 high to indicate Control Word Mode
Information.
INTERNAL
INTERNAL
DATA OUT
INTERNAL
INTERNAL
DATA OUT
MASTER
MASTER
DATA IN
DATA IN
RESET
RESET
One 8-bit data output latch/buffer and one 8-bit data input
buffer (no latch for input). This port can be divided into two
4-bit ports under the mode control. Each 4-bit port contains
a 4-bit latch and can be used for the control signal outputs
and status signal inputs in conjunction with Ports A and B.
See Figure 9B.
FIGURE 9. I/O PORT CONFIGURATION
SIGNAL
WR
SIGNAL
FIGURE 9A.
FIGURE 9B.
WR
7
RD
CONTROL
VDD
P
EXTERNAL
PORT A PIN
EXTERNAL
PORT B, C
PIN
HS-82C55ARH
FIGURE 10. BASIC MODE DEFINITIONS AND BUS INTERFACE
MODE 0
MODE 1
MODE 2
A1
A1
A1
X
0
0
1
1
0
0
1
1
A0
A0
A0
X
0
1
0
1
0
1
0
1
PB7 - PB0 PC3 - PC0 PC7 - PC4 PA7 - PA0
PB7 - PB0
PB7 - PB0
RD, WR
RD
RD
RD
0
0
0
0
1
1
1
1
X
B
8
B
8
B
8
I/O
I/O
I/O
WR
WR
WR
X
1
1
1
1
0
0
0
0
CONTROL
OR I/O
TABLE 1.
TABLE 2.
TABLE 3.
I/O
ADDRESS BUS
CONTROL BUS
4
DATA BUS
CS
CS
CS
D7 - D0
I/O
0
0
0
0
0
0
0
0
1
C
C
C
CONTROL
CONTROL
Port A - Data Bus
Port B - Data Bus
Port C - Data Bus
Control Word - Data Bus
Data Bus - Port A
Data Bus - Port B
Data Bus - Port C
Data Bus - Control Word
Data Bus - 3-State
OR I/O
4
OUTPUT OPERATION
DISABLE FUNCTION
INPUT OPERATION
I/O
PA7 - PA0
PA7 - PA0
(WRITE)
A0 - A1
(READ)
CS
A
8
A
8
A
8
I/O
I/O
BIDIREC-
TIONAL