AT89C51RD2-RDTIM Atmel, AT89C51RD2-RDTIM Datasheet - Page 2

• Manufacturer Part Number: AT89C51RD2-RDTIM
• Description: MCU 8-Bit AT89 80C51 CISC 64KB Flash 3.3V/5V 64-Pin VQFP Tray
• Manufacturer: Atmel

1. Description
2
AT89C51RD2/ED2
AT89C51RD2/ED2 is high performance CMOS Flash version of the 80C51 CMOS single chip 8-
bit microcontroller. It contains a 64-Kbyte Flash memory block for code and for data.
The 64-Kbytes Flash memory can be programmed either in parallel mode or in serial mode with
the ISP capability or with software. The programming voltage is internally generated from the
standard V
The AT89C51RD2/ED2 retains all of the features of the Atmel 80C52 with 256 bytes of internal
RAM, a 9-source 4-level interrupt controller and three timer/counters. The AT89C51ED2 pro-
vides 2048 bytes of EEPROM for nonvolatile data storage.
In addition, the AT89C51RD2/ED2 has a Programmable Counter Array, an XRAM of 1792
bytes, a Hardware Watchdog Timer, SPI interface, Keyboard, a more versatile serial channel
that facilitates multiprocessor communication (EUART) and a speed improvement mechanism
(X2 Mode).
The fully static design of the AT89C51RD2/ED2 allows to reduce system power consumption by
bringing the clock frequency down to any value, including DC, without loss of data.
The AT89C51RD2/ED2 has 2 software-selectable modes of reduced activity and an 8-bit clock
prescaler for further reduction in power consumption. In the 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.
The added features of the AT89C51RD2/ED2 make it more powerful for applications that need
pulse width modulation, high speed I/O and counting capabilities such as alarms, motor control,
corded phones, and smart card readers.
Table 1-1.
PLCC44/VQFP44
PLCC68/VQFP64
Package
CC
pin.
Memory Size and I/O Pins
Flash (Bytes)
64K
64K
XRAM (Bytes)
1792
1792
Total RAM (Bytes)
2048
2048
4235J–8051–01/08
I/O
34
50