This application note describes the implementation ofvarious digital filters using the PIC17C42, the firstmember of Microchip’s 2nd generation of 8-bitmicrocontrollers. The PIC17C42 is a very high speed8-bit microcontroller with an instruction cycle time of250 ns (@ 16 MHz input clock). Even though thePIC17C42 is an 8-bit device, it’s high speed and efficientinstruction set allows implementation of digital filtersfor practical applications. Traditionally digital filtershave been implemented using expensive Digital SignalProcessors (DSPs). In a system the DSP is normally aslave processor being controlled by either an 8-bit or16-bit microcontroller. Where sampling rates are nothigh (especially in mechanical control systems), a singlechip solution is possible using the PIC17C42.