Fcop Mode 0: Real Fir Filter; Mode 0 (Real Fir Filter), No Decimation - Motorola DSP56305 User Manual

12.5.5

FCOP Mode 0: Real FIR Filter

Mode 0 is selected when FOM[1:0] = 00. In this mode, calculation of filter outputs
considers data and coefficient words as real numbers.
12.5.5.1

Mode 0 (Real FIR Filter), No Decimation

The following equation is implemented:
Set Up
DSP
Initialization
Processing
MOTOROLA
N 1 –
∑
F n ( ) H i ( ) D n i –
=
i = 0
• Load Filter Count Register (FCNT) with (number of coefficient
values – 1)
• Choose operation mode (FOM[1:0], FDCM=0) and enable
FCOP (FEN = 1)
• Core initializes coefficients in FCM in reverse order by
executing #filter_count writes to FCIR
• Core or DMA initializes data in FDM in direct order by
executing #filter_count writes to FDIR
• Whenever FDIR is empty (FDIBE = 1), FCOP triggers core or
DMA to transfer up to four new data words to FDM via FDIR
• Compute F(n) and store result in FDOR
• FCOP triggers core or DMA for output data transfer
• Get new data word
• FCOP increments data memory pointer
DSP56305 User's Manual
⋅ ( )
Filter Co-Processor
Operation Modes
12-17