DESCRIPTION
Three different Single-Chip 8-Bit Microcontroller families are presented in this datasheet:
•80C32/8XC52/8XC54/8XC58
•80C51FA/8XC51FA/8XC51FB/8XC51FC
•80C51RA+/8XC51RA+/8XC51RB+/8XC51RC+/8XC51RD+
For applications requiring 4K ROM/EPROM, see the 8XC51/80C31 8-bit CMOS (low voltage, low power, and high speed) microcontroller families datasheet.

FEATURES
•80C51 Central Processing Unit
•Speed up to 33MHz
•Full static operation
•Operating voltage range: 2.7V to 5.5V @ 16MHz
•Security bits:
–ROM – 2 bits
–OTP–EPROM – 3 bits
•Encryption array – 64 bytes
•RAM expandable to 64K bytes
•4 level priority interrupt
•6 or7 interrupt sources, depending on device
•Four 8-bit I/O ports
•Full-duplex enhanced UART
–Framing error detection
–Automatic address recognition
•Power control modes
–Clock can be stopped and resumed
–Idle mode
–Power down mode
•Programmable clock out
•Second DPTR register
•Asynchronous port reset
•Low EMI (inhibit ALE)