CP82C55A Intersil, CP82C55A Datasheet - Page 14

• Manufacturer Part Number: CP82C55A
• Description: IC I/O EXPANDER 24B 40DIP
• Manufacturer: Intersil

Specifications of CP82C55A

• Interface: Programmable
• Number Of I /o: 24
• Interrupt Output: No
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 40-DIP (0.600", 15.24mm)
• Chip Configuration: 8 Bit
• Bus Frequency: 8MHz
• No. Of I/o's: 24
• Supply Voltage Range: 4.5V To 5.5V
• Digital Ic Case Style: DIP
• No. Of Pins: 40
• Function: Programmable I/O
• Rohs Compliant: No
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Frequency - Clock: -

Special Mode Combination Considerations
There are several combinations of modes possible. For any
combination, some or all of Port C lines are used for control
or status. The remaining bits are either inputs or outputs as
defined by a “Set Mode” command.
During a read of Port C, the state of all the Port C lines,
except the ACK and STB lines, will be placed on the data
bus. In place of the ACK and STB line states, flag status will
appear on the data bus in the PC2, PC4, and PC6 bit
positions as illustrated by Figure 17.
Through a “Write Port C” command, only the Port C pins
programmed as outputs in a Mode 0 group can be written.
No other pins can be affected by a “Write Port C” command,
nor can the interrupt enable flags be accessed. To write to
any Port C output programmed as an output in Mode 1
group or to change an interrupt enable flag, the “Set/Reset
Port C Bit” command must be used.
With a “Set/Reset Port C Bit” command, any Port C line
programmed as an output (including IBF and OBF) can be
written, or an interrupt enable flag can be either set or reset.
Port C lines programmed as inputs, including ACK and STB
lines, associated with Port C are not affected by a “Set/Reset
Port C Bit” command. Writing to the corresponding Port C bit
positions of the ACK and STB lines with the “Set Reset Port
C Bit” command will affect the Group A and Group B
interrupt enable flags, as illustrated in Figure 17.
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PC0
PC1
PC2
PC3
PC4
PC5
PC6
PC7
14
IN
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
MODE 0
OUT
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
MODE DEFINITION SUMMARY
82C55A
INTRB
INTRA
STBB
STBA
IBFB
IBFA
I/O
I/O
IN
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
Current Drive Capability
Any output on Port A, B or C can sink or source 2.5mA. This
feature allows the 82C55A to directly drive Darlington type
drivers and high-voltage displays that require such sink or
source current.
Reading Port C Status
In Mode 0, Port C transfers data to or from the peripheral
device. When the 82C55A is programmed to function in
OBFA INTEA
OBFA INTE1
I/O
D7
D7
D7
MODE 1
FIGURE 15. MODE 1 STATUS WORD FORMAT
FIGURE 16. MODE 2 STATUS WORD FORMAT
D6
I/O
D6
D6
(Defined by Mode 0 or Mode 1 Selection)
INTRB
INTRA
OBFB
ACKB
ACKA
OBFA
OUT
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
Out
I/O
I/O
GROUP A
GROUP A
GROUP A
IBFA
IBFA
OUTPUT CONFIGURATION
D5
D5
I/O
D5
INPUT CONFIGURATION
INTEA INTRA INTEB
INTE2 INTRA
I/O
D4
D4
D4
(Figures 15 and 16)
GROUP A ONLY
INTRA INTEB OBFB INTRB
MODE 2
D3
D3
D3
INTRA
ACKA
OBFA
STBA
IBFA
I/O
I/O
I/O
D2
D2
D2
X
GROUP B
GROUP B
GROUP B
November 16, 2006
IBFB
D1
D1
D1
X
Mode 0
or Mode 1
Only
FN2969.10
INTRB
D0
D0
D0
X