The DS89C450-MNL+ is an ultra high speed flash microcontroller in 40 pin DIP package. It is a standard 8051 compatible microcontroller and includes standard resources such as three timer/counters, serial port and four 8-bit I/O ports. The newly designed processor cores that execute instructions up to 12 times faster than the original 8051 at the same crystal speed. Typical applications have a speed improvement of up to 10 times. At 1MIPS/MHz, the microcontrollers achieve 33MIPS performance from a maximum 33MHz clock rate. It include 1KB of data RAM, a second full hardware serial port, seven additional interrupts, two extra levels of interrupt priority, programmable watchdog timer, brownout monitor and power-fail reset. Dual data pointers (DPTRs) are included with automatic increment/decrement and toggle select operation. The speed of MOVX data memory access can be adjusted by adding stretch values up to 10 machine cycles for flexibility in selecting external memory and peripherals.