AT89C4051
KEY BOARD
IC73
Pin Configuration
PDIP/SOIC
RST/VPP 1
(RXD) P3.0 2
(TXD) P3.1 3
XTAL2 4
XTAL1 5
( INT0 ) P3.2 6
(TO) P3.4 8
( INT1 ) P3.3 7
(T1) P3.5 9
GND 10
P3.7
11
P1.0 (AIN0)
12
P1.1 (AIN1)
13
P1.2
14
P1.3
15
P1.4
16
P1.5
17
P1.6
18
P1.7
19
VCC
20
RAM ADDR.
REGISTER
RMA
B
REGISTER
ACC
TMP2
TMP1
ALU
PSW
TIMING
AND
CONTROL
INSTRUCTION
REGISTER
OSC
+
-
ANALOG
COMPARATOR
PORT 1
LATCH
PORT 1 DRIVERS
PORT 3 DRIVERS
PORT 3
LATCH
INTERRUPT SERIAL PORT
AND TIMER BLOCKS
DPTR
PROGRAM
COUNTER
PC
INCREMENTER
BUFFER
PROGRAM
ADDRESS
REGISTER
FLASH
STACK
POINTER
P 1.0 - P 1.7
P 3.0 - P 3.5
P 3.7
RST
Vcc
GND
Block Diagram
14
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