User Manual

2
T89C51AC2
Rev. B – 19-Dec-01
The added features of t he T89C5 1AC2 make it m ore powerful for applications that need
A/D conversion, pulse width mo dulation, hi gh speed I/O and counting ca pabiliti es suc h
as industrial control, cons umer goods, al arms, motor cont rol, etc.
While remaining fully compatible with the 80C52 it offers a superset of this standard
microcont roller. In X2 m ode a maxim um external clock rate of 20 MHz reaches a 30 0 ns
cycle time.
3. Block Diagram
Timer 0
INT
RAM
256x8
T0 T1
RxD TxD
WR
RD
EA
PSEN
ALE
XTAL2
XTAL1
UART
CPU
Timer 1
INT1
Ctrl
INT0
C51
CORE
Port 0
P0
Port 1
Port 2
Port 3
Parallel I/O Ports & Ext. Bus
P1(1)
P2 P3
ERAM
1kx8
IB-bus
PCA
RESET
Watch
Dog
PCA ECI
Vss Vcc
(1): 8 analog Inputs / 8 Digital I/O
Timer2
T2EX
T2
Port 4
P4(2)
Emul
Unit
10 bit
ADC
Flash
32kx
8
Boot
loader
2kx8
EE
PROM
2kx8
(2): 2-Bit I/O Port