Intel MCS48 User Manual page 299

intel
8253/8253-5
PROGRAMMABLE INTERVAL TIMER
MCS—
85™
Compatible
8253-5
3
Independent
16-Bit
Counters
DC
to
2
MHz
Programmable Counter
Modes
Count
Binary or
BCD
Single
+ 5V
Supply
24-Pin Dual In-Line
Package
The
Intel®
8253
is
a
programmable
counter/timer chip
designed
for
use as an
Intel
microcomputer
peripheral.
It
uses
nMOS
technology with a
single
+5V
supply
and
is
packaged
in
a 24-pin plastic DIP.
It
is
organized as 3 independent
16-bit
counters, each with a
count
rate of
up
to 2
MHz.
All
modes
of
operation are
soft-
ware programmable.
PIN
CONFIGURATION
BLOCK DIAGRAM
D
7
C
CLK0[
OUT0[
GATEOl
GNDl
6
8253
is
C
9
C
10
C
11
C
12
3v
cc
Uwr
3rd
3cs
3a,
I!a
UCLK2
3 OUT
2
J
GATE
2
DCLK
1
3
GATE
1
DOUT1
PIN
NAMES
D
7
D
DATA
BUS
(8
BIT)
CLK
N
COUNTER CLOCK
INPUTS
GATE
N
COUNTER GATE
INPUTS
OUT
N
COUNTER OUTPUTS
RD READ COUNTER
WR
WRITE
COMMAND OR DATA
CS
CHIP SELECT
A
n
A,
COUNTER
SELECT
Vcr.
5
VOLTS
GND GROUND
READ/
WRITE
LOGIC
CONTROL
WORD
REGISTER
INTERNAL BUS
COUNTER
CLK
GATEO
OUT0
CLK
1
GATE
1
CLK
2
•
GATE
2
•OUT
2
INTEL
COKKKATION ASSUMES NO RESPONSIBILITY FOR THE USE OF
ANY
CIRCUITRY
OTHER THAN CIRCUITRY EMBODIED
IN
AN INTEL PRODUCT.
NO OTHER
CIRCUIT PATENT
LICENSES ARE
IMPLffiD.
e
INTEL
CORPORATION, 1979
g.g
00745A