FEATURES
• 80C51 central processing unit
• 8k × 8 ROM expandable externally to 64k bytes
• 256 × 8 RAM, expandable externally to 64k bytes
• Two standard 16-bit timer/counters
• Four 8-bit I/O ports
• I2C-bus serial I/O port with byte oriented master and slave functions
• Full-duplex UART facilities
• Power control modes
   – Idle mode
   – Power-down mode
• ROM code protection
• Extended frequency range: 3.5 to 24 MHz
• Three operating ambient temperature ranges:
   0 to +70°C
   –40 to +85°C
   –40 to +125°C