IIR数字滤波器实现

Thisapplicationnotedescribestheimplementationof

variousdigitalfiltersusingthePIC17C42,thefirst

memberofMicrochip’s2ndgenerationof8-bit

microcontrollers.ThePIC17C42isaveryhighspeed

8-bitmicrocontrollerwithaninstructioncycletimeof

250ns(@16MHzinputclock).Eventhoughthe

PIC17C42isan8-bitdevice,it’shighspeedandeffi-

cientinstructionsetallowsimplementationofdigitalfil-

tersforpracticalapplications.Traditionallydigitalfilters

havebeenimplementedusingexpensiveDigitalSignal

Processors(DSPs).InasystemtheDSPisnormallya

slaveprocessorbeingcontrolledbyeitheran8-bitor

16-bitmicrocontroller.Wheresamplingratesarenot

high(especiallyinmechanicalcontrolsystems),asin-

glechipsolutionispossibleusingthePIC17C42.AN540ImplementingIIRDigitalFiltersTHEORYOFOPERATIONAuthor:AmarPalacherlaMicrochipTechnologyInc.DigitalltersinmostcasesassumethefollowingformofrelationshipbetweentheoutputandinputINTRODUCTIONsequences.ThisapplicationnotedescribestheimplementationofvariousdigitalltersusingthePIC17C42,therstmemberofMicrochip’s2ndgenerationof8-bit