IIR ARMA 16-bit filter

UM0304

8/19

2.7

Implementation

●

The output vector y[] contains ny + 4 locations, but its first 4 data are not used, i.e., first

output is y[4] while ny = 0.

●

The inner loop that iterated through the filter coefficients is completely unrolled.

●

The code is little ENDIAN.

●

The code is interrupt-tolerant but not interruptible.

2.8

Benchmarking

The benchmarking for this filter function is done using Chameleon Trace while the filter

function is running in STR91x engine with ARM966E-S. For the Chameleon Trace in ETM

Configuration Trace Port Size is set to 8 bit and Trace Port Mode is set to Normal, Half-rate

clocking, while the STR91x engine runs at 96 MHz.

Table 2.

Benchmarking of IIR ARMA algorithm module

Number of taps

Cycle count

Microseconds

72

6544

68.167

48

4396

45.792

24

2248

23.417