IMQ82C55AZ96 Intersil, IMQ82C55AZ96 Datasheet - Page 15

• Manufacturer Part Number: IMQ82C55AZ96
• Description: IC I/O EXPANDER 24B 44MQFP
• Manufacturer: Intersil

Specifications of IMQ82C55AZ96

• Interface: Programmable
• Number Of I /o: 24
• Interrupt Output: No
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 44-MQFP, 44-PQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Clock: -

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
Modes 1 or 2, Port C generates or accepts “hand shaking”
signals with the peripheral device. Reading the contents of
Port C allows the programmer to test or verify the “status” of
each peripheral device and change the program flow
accordingly.
There is not a special instruction to read the status
information from Port C. A normal read operation of Port C is
executed to perform this function.
ENABLE FLAG
FIGURE 17. INTERRUPT ENABLE FLAGS IN MODES 1 AND 2
INTERRUPT
INTE A2
INTE A1
INTE B
POSITION
PC2
PC4
PC6
(Figures 15 and 16)
15
ACKB (Output Mode 1)
or STBB (Input Mode 1)
STBA (Input Mode 1 or Mode 2)
ACKA (Output Mode 1 or Mode 2)
INTERRUPT
INTERRUPT
REQUEST
REQUEST
ALTERNATE PORT C
PIN SIGNAL (MODE)
MS82C55A, MQ82C55A, MP82C55A
(OUTPUT)
(OUTPUT)
MODE 1
MODE 1
82C55A
PC3
PC0
FIGURE 18. PRINTER INTERFACE
PC7
PC6
PC5
PC4
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PC1
PC2
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
CONTROL LOGIC
DATA READY
ACK
PAPER FEED
FORWARD/REV.
DATA READY
ACK
AND DRIVERS
Applications of the 82C55A
The 82C55A is a very powerful tool for interfacing peripheral
equipment to the microcomputer system. It represents the
optimum use of available pins and is flexible enough to
interface almost any I/O device without the need for
additional external logic.
Each peripheral device in a microcomputer system usually
has a “service routine” associated with it. The routine
manages the software interface between the device and the
CPU. The functional definition of the 82C55A is programmed
by the I/O service routine and becomes an extension of the
system software. By examining the I/O devices interface
characteristics for both data transfer and timing, and
matching this information to the examples and tables in the
detailed operational description, a control word can easily be
developed to initialize the 82C55A to exactly “fit” the
application. Figures 18 through 24 present a few examples
of typical applications of the 82C55A.
PAPER FEED
FORWARD/REV.
RIBBON
CARRIAGE SEN.
HIGH SPEED
HAMMER
RELAYS
PRINTER
June 15, 2006
FN6140.2