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8279/8279-5
PROGRAMMABLE
KEYBOARD/DISPLAY INTERFACE
MCS-85™
Compatible
8279-5
Simultaneous Keyboard
Display
Operations
Scanned
Keyboard
Mode
Scanned
Sensor
Mode
Strobed
Input Entry
Mode
8-Character
Keyboard FIFO
2-Key Lockout
or
N-Key
Rollover with
Contact
Debounce
Dual
8-
or
16-Numerical Display
Single 16-Character Display
Right or Left Entry
16-
Byte Display
RAM
Mode
Programmable
from
CPU
Programmable Scan Timing
Interrupt
Output on Key
Entry
The
Intel®
8279
is
a general purpose
programmable keyboard and
display
I/O
interface device
designed
for
use
with
Intel®
microprocessors.
The
keyboard
portion
can provide a
scanned
interface to
a 64-contact key
matrix.
The
keyboard
portion
will
also
interface to
an
array
of
sensors or
a strobed
interface keyboard,
such
as the
hall
effect
and
ferrite
variety.
Key depressions can be
2-key lockout or N-key
rollover.
Keyboard
entries are
debounced and
strobed
in
an 8-character FIFO.
If
more
than 8 characters
are entered, overrun status
is
set.
Key
entries set the interrupt output
line
to
the
CPU.
The
display portion provides a scanned display interface
for
LED, incandescent, and
other popular display
technologies.
Both numeric and alphanumeric segment
displays
may
be used as
well
as simple
indicators.
The 8279
has 16X8
display
RAM
which can be
organized into
dual 16X4.
The
RAM
can be loaded
or interrogated by the
CPU. Both
right entry,
calculator
and
left
entry typewriter display
formats
are possible.
Both
read
and
write of
the display
RAM
can be
done
with auto-increment
of
the display
RAM
address.
PIN
CONFIGURATION
RL
2
C
1
V
40
Uv
cc
RL3C
2 39
DHL,
clkC
3 1«
DRU
irqC
4 37
^CNTL/STB
RUC
5 36 J
SHIFT
RL5C
6 35
HSL3
RUC
34
HSL
2
RL
?
C 8 33
:sl,
resetC
rdC
9 32
8279
10 31
DSLo
3 OUT
B
wrC
11 30
DOUT
B,
DB„C
12 29
D OUT
B
2
DB,r: 13 28
3 OUT
B
3
DB
2
C
14 27
1 OUT A
DB3C
15
26
UOUT
A,
DB
4
C
16 25
Uqut a
2
DB
5
C
17
24
3
out
A3
DBjC
18 23
U6T5
DB
7
C 19 22 I]cs
v
ssC
20
21
Da
LOGIC
SYMBOL
PIN
NAMES
DB
)
I/O
DATA BUS
IBI
DIRECTIONAL!
CLK
1
CLOCK INPUT
RESET
1
RESET INPUT
C?
1
CHIP
SELECT
rE
1
READ
INPUT
M- -\
WRITE INPUT
Ao
1
BUFFER ADDRESS
IRQ
INTERRUPT REQUEST OUTPUT
SU3
SCANUNES
RL07
1
RETURN
LINES
SHIFT
1
SHIFT INPUT
CNTL/STB
1
CONTROL/STROBE INPUT
OUT A
03
DISPLAY
IAI
OUTPUTS
OUT
B03
DISPLAY
IB)
OUTPUTS
SB
BLANK
DISPLAY
OUTPUT
<x>
IRQ
RL0.7
<^
CLK OUT
B 03
1
>
t>
:>
INTEL
CORPORATION ASSUMES NO
RESPONSIBILITY
FOR THE
USE OF ANY CIRCUITRY
OTHER THAN
CIRCUITRY
EMBODIED
IN
AN INTEL PRODUCT.
NO OTHER
CIRCUIT
PATENT LICENSES
ARE
IMPLIED.
©
INTEL
CORPORATION, 1979 3.72
00742A