The DS89C420 offers the highest performance available in 8051-compatible microcontrollers. It features a redesigned processor core which executes every 8051 instruction up to 12 times faster than the original for the same crystal speed, thus allowing very significant improvements using the same code and crystal. The DS89C420 offers a maximum crystal speed of 50 MHz, achieving execution rates up to 50 MIPs for short instructions.The DS89C420 is pin-compatible with all three packages of the standard 8051 and includes standard resources such as three timer/counters, serial port, and four 8-bit I/O ports. It features 16 kbits of “In System Programmable” flash memory which can be programmed in system from an I/O port using a built in program memory loader or from resident user software. It can also be loaded externally using standard commercially available programmers.