AT80C51RD2 Atmel Corporation, AT80C51RD2 Datasheet - Page 2

• Manufacturer Part Number: AT80C51RD2
• Manufacturer: Atmel Corporation

Specifications of AT80C51RD2

• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Uart: 1
• Sram (kbytes): 1.25
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Watchdog: Yes

1. Description
2. Block Diagram
2
AT80C51RD2
ALE/
XTAL1
XTAL2
PSEN
PROG
WR
RD
EA
AT80C51RD2 microcontrollers are high performance versions of the 80C51 8-bit
microcontrollers.
The microcontrollers retain all features of the Atmel 80C52 with 256 bytes of internal RAM, a 7-
source 4-level interrupt controller and three timer/counters.
In addition, the microcontrollers have a Programmable Counter Array, an XRAM of 1024 byte, a
Hardware Watchdog Timer, a Keyboard Interface, a more versatile serial channel that facilitates
multiprocessor communication (EUART) and a speed improvement mechanism (X2 mode).
The microcontrollers have 2 software-selectable modes of reduced activity and 8 bit clock pres-
caler for further reduction in power consumption. In Idle mode, the CPU is frozen while the
peripherals and the interrupt system are still operating. In the Power-down mode, the RAM is
saved and all other functions are inoperative.
Table 1. Memory Size
Notes:
(2)
(2)
AT80C51RD2
CPU
1. Alternate function of Port 1
2. Alternate function of Port 3
(2) (2)
(2)
Timer 0
Timer 1
EUART
BRG
(2)
+
CORE
C51
(2) (2)
256x8
RAM
INT
Ctrl
ROM (Bytes)
ROMless
IB-bus
Parallel I/O Ports & Ext. Bus
Port 0Port 1 Port 2 Port 3
XRAM
1Kx8
XRAM (Bytes)
(1)
1024
PCA
(1)
(1)
Watch
Dog
Timer2
(1)
TOTAL RAM (Bytes)
Board
Key
1280
4113D–8051–01/09
I/O
32