Rainbow Electronics T89C51AC2 - Manual (Page 2)

2
T89C51AC2
Rev. B – 19-Dec-01
The added features of the T89C51AC2 make it more powerful for applications that need
A/D conversion, pulse width modulation, high speed I/O and counting capabilities such
as industrial control, consumer goods, alarms, motor control, etc.
While remaining fully compatible with the 80C52 it offers a superset of this standard
microcontroller. In X2 mode a maximum external clock rate of 20 MHz reaches a 300 ns
cycle time.
3. Block Diagram
Timer 0 INT
RAM
256x8
T0 T1
Rx
D
Tx
D
WR
RD
EA
PSEN
ALE
XTAL2
XTAL1
UART
CPU
Timer 1
INT
1
Ctrl
INT
0
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
RE
S
E
T
Watch
Dog
PC
A
EC
I
Vs
s
Vc
c
(1): 8 analog Inputs / 8 Digital I/O
Timer2
T2
E
X
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