The Atmel AT89C2051 is an 8051-based Fully Static 24MHz CMOS controller with 15 I/O Lines, 2 Timers/Counters, 6 Interrupts/2 Priority Levels, Analog Comparator, LED Drive Outputs, UART, Two-level Program Memory Lock, 2K Bytes Flash Memory, 128 Bytes On-chip RAM.