Description
The AT89S53 is a low-power, high-performance CMOS 8-bit microcomputer with 12K bytes of Downloadable Flash programmable and erasable read only memory.

FEATUREs
• Compatible with MCS-51™ Products
• 12K Bytes of In-System Reprogrammable Downloadable Flash Memory
   – SPI Serial Interface for Program Downloading
   – Endurance: 1,000 Write/Erase Cycles
• 4.0V to 6V Operating Range
• Fully Static Operation: 0 Hz to 24 MHz
• Three-Level Program Memory Lock
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Nine Interrupt Sources
• Programmable UART Serial Channel
• SPI Serial Interface
• Low Power Idle and Power Down Modes
• Interrupt Recovery From Power Down
• Programmable Watchdog Timer
• Dual Data Pointer
• Power Off Flag