This application note describes the implementation of
various digital filters using the PIC17C42, the first
member of Microchip’s 2nd generation of 8-bit
microcontrollers. The PIC17C42 is a very high speed
8-bit microcontroller with an instruction cycle time of
250 ns (@ 16 MHz input clock). Even though the
PIC17C42 is an 8-bit device, it’s high speed and effi-
cient instruction set allows implementation of digital fil-
ters for practical applications. Traditionally digital filters
have been implemented using expensive Digital Signal
Processors (DSPs). In a system the DSP is normally a
slave processor being controlled by either an 8-bit or
16-bit microcontroller. Where sampling rates are not
high (especially in mechanical control systems), a sin-
gle chip solution is possible using the PIC17C42. AN540
Implementing IIR Digital Filters
THEORY OF OPERATION
Author: Amar Palacherla
Microchip Technology Inc. Digital lters in most cases assume the following form
of relationship between the output and input
INTRODUCTION sequences.
This application note describes the implementation of
various digital lters using the PIC17C42, the rst
member of Microchip’s 2nd generation of 8-bit
……
