Datasheet

3
AT89C51RB2/RC2
4180D–8051–06/05
Block Diagram
Figure 1. Block Diagram
Notes: 1. Alternate function of Port 1.
2. Alternate function of Port 3.
Timer 0
INT
RAM
256x8
T0 T1
RxD TxD
WR
RD
EA
PSEN
ALE/
XTAL2
XTAL1
EUART
CPU
Timer 1
INT1
Ctrl
INT0
(2)
(2)
C51
CORE
(2) (2) (2) (2)
Port 0
P0
Port 1
Port 2 Port 3
Parallel I/O Ports & Ext. Bus
P1 P2 P3
XRAM
1Kx8
IB-bus
PCA
RESET
PROG
Watch
Dog
PCA ECI
Vss V
CC
(2)(2)
(1)(1)
Timer2
T2EX
T2
(1) (1)
Flash
32Kx8 or
16Kx8
Key
Board
ROM
2Kx8
Boot
+
BRG
SPI
MISO
MOSI SCK
(1) (1) (1)
SS
(1)