The AT91M55800A is a member of the Microchip AT91 16/32-bit microcontroller family,which is based on the ARM7TDMI processor core. This processor has a high-performance32-bit RISC architecture with a high-density 16-bit instruction set and very lowpower consumption. In addition, a large number of internally banked registers result invery fast exception handling, making the device ideal for real-time controlapplications. The fully programmable External Bus Interface provides a direct connection to off-chip memory in as fast as one clockcycle for a read or write operation. An eight-level priority vectored interrupt controller in conjunction with the peripheral datacontroller significantly improve the real-time performance of the device.The device is manufactured using Microchip’s high-density CMOS technology. By combining the ARM7TDMI processor corewith an on-chip SRAM, a wide range of peripheral functions, analog interfaces and low-power oscillators on a monolithicchip, the Microchip AT91M55800A is a powerful microcontroller that provides a highly-flexible and cost-effective solution tomany ultra low-power applications.