Features
• 80C52 Compatible
– Four 8-bit I/O Ports
– Three 16-bit Timer/Counters
– 256 Bytes Scratch Pad RAM
– 8 Interrupt Sources with 4 Priority Levels
– Dual Data Pointer
• Variable Length MOVX for Slow RAM/Peripherals
• High-speed Architecture
– 10 to 40 MHz in Standard Mode
• 16K/32K Bytes On-Chip ROM Program
• T80C51RD2 ROMless Versions
• On-Chip 1024 bytes Expanded RAM (XRAM)
– Software Selectable Size (0, 256, 512, 768, 1024 bytes)
– 256 Bytes Selected at Reset for AT87C51RB2/RC2 Compatibility
• Keyboard Interrupt Interface on Port P1
• 8-bit Clock Prescaler
• 64K Program and Data Memory Spaces
• Improved X2 Mode with Independant Selection for CPU and Each Peripheral
• Programmable Counter Array 5 Channels with:
– High-speed Output
80C51 High
Performance
ROM 8-bit
Microcontroller
AT80C51RD2
AT83C51RB2
AT83C51RC2
– Compare/Capture
– Pulse Width Modulator
– Watchdog Timer Capabilities
• Asynchronous Port Reset
• Full Duplex Enhanced UART
• Dedicated Baud Rate Generator for UART
• Low EMI (Inhibit ALE)
• Hardware Watchdog Timer (One-time Enabled with Reset-out)
• Power Control Modes
– Idle Mode
– Power-down Mode
– Power-off Flag
• Power Supply: 2.7V to 5.5V or 2.7V to 3.6V
• Temperature Ranges: Commercial (0 to +70°C) and Industrial (-40°C to +85°C)
• Packages: PDIL40, PLCC44, VQFP44
Description
AT8xC51Rx2 microcontrollers are high performance ROM versions of the 80C51 8-bit
microcontrollers. They contain a 0K, 16K or 32K bytes ROM memory block for
program.
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 improve-
ment mechanism (X2 mode).
The microcontrollers have 2 software-selectable modes of reduced activity and 8 bit
clock prescaler 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.
Rev. 4113A–8051–09/02