DESCRIPTION
Three different Single-Chip 8-Bit Microcontroller families are presented in this datasheet:
   • 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 33 MHz
• Full static operation
• Operating voltage range: 2.7 V to 5.5 V @ 16 MHz
• 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)