HS-82C55ARH(1995) Ver la hoja de datos (PDF) - Intersil
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HS-82C55ARH Datasheet PDF : 23 Pages
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HS-82C55ARH
The mode definitions and possible mode combinations may
seem confusing at first but after a cursory review of the
complete device operation a simple, logical I/O approach will
surface. The design of the HS-82C55ARH has taken into
account things such as efficient PC board layout, control
signal definition vs PC layout and complete functional
flexibility to support almost any peripheral device with no
external logic. Such design represents the maximum use of
the available pins.
CONTROL WORD
D7 D6 D5 D4 D3 D2 D1 D0
XX X
DON’T
CARE
BIT SET/RESET
1 = SET
0 = RESET
BIT SELECT
01234567
0 1 0 1 0 1 0 1 B0
0 0 1 1 0 0 1 1 B1
0 0 0 0 1 1 1 1 B2
BIT SET/RESET FLAG
0 = ACTIVE
FIGURE 12. BIT SET/RESET CONTROL WORD FORMAT
Single Bit/Set/Reset Feature
Any of the eight bits of Port C can be Set or Reset using a
single OUTput instruction. See Figure 12. This feature
reduces software requirements in control-based
applications.
Interrupt Control Functions
When the HS-82C55ARH is programmed to operate in
Mode 1 or Mode 2, control signals are provided that can be
used as interrupt request inputs to the CPU. The interrupt
request signals, generated from Port C, can be inhibited or
enable by setting or resetting the associated INTE flip-flop,
using the Bit Set/Reset function of Port C.
This function allows the programmer to enable or disable a
CPU interrupt by a specific I/O device without affecting any
other device in the interrupt structure.
INTE Flip-Flop Definition:
(BIT-SET) - INTE is SET - Interrupt enable.
(BIT-RESET) - INTE is RESET - Interrupt disable.
NOTE: All mask flip-flops are automatically reset during
mode selection and device Reset.
Operating Modes
Mode 0 (Basic Input/Output)
This functional configuration provides simple input and out-
put operations for each of the three ports. No handshaking it
required, data is simply written to or read from a specific
port.
Mode 0 Basic Functional Definitions:
• Two 8-bit ports and two 4-bit ports
• Any port can be input or output
• Outputs are latched
• Inputs are not latched
• 16 different Input/Output configurations possible
RD
INPUT
CS, A1, A0
D7 - D0
TPVRL
TAVRL
TRLRH
TRHPX
TRHAX
TRLDV
FIGURE 13. MODE 0 (BASIC INPUT)
TRHDX
WR
D7 - D0
CS, A1, A0
OUTPUT
TAVWL
TWLWH
TDVWH
TWHDX
TWHAX
TWHPV
FIGURE 14. MODE 0 (BASIC OUTPUT)
983
Spec Number 518060
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