PM0014 datasheet(44/46 Pages) STMICROELECTRONICS

44 / 46 page

Signal processing library functions

PM0014

44/46

Coefficients must be stored in memory as follow:

addr

Iir.CoeffPtr ----> b00

addr

Iir.CoeffPtr + 2 ----> b10

addr

Iir.CoeffPtr + 4----> b20

addr

Iir.CoeffPtr +6----> a10

addr

Iir.CoeffPtr + 8 ----> a20

...

addr

Iir.CoeffPtr + 2 * 5 * (Q - 1)----> b0(Q-1)

addr

Iir.CoeffPtr + 2 * 5 *(Q-1) + 2----> b1(Q-1)

addr

Iir.CoeffPtr + 2 * 5 * (Q - 1) + 4 ----> b2(Q-1)

addr

Iir.CoeffPtr + 2 * 5 * (Q - 1) + 6 ----> a1(Q-1)

addr

Iir.CoeffPtr + 2 * 5 *(Q-1) + 8----> a2(Q-1)

Assembly source

code:

iirBiquad5_q15_q15_q15.asm

Code size and cycles: Size: 136 bytes

Instruction Cycles: 34 + NbOutput * (12 + 15 * IirNumberCells)

Test:

Two test cases are provided. For each test case, two files allow to

test the function: an input vector file (BiqFilterX_q15_q15_q15.in)

and an output vector file (BiqfilterX_q15_q15_q15.res). The

configuration is the following:

number of cells: 3

number of output samples: 201

To perform the test, initialize the Delay line[] to zero, then Coeff[]

and Input[] with the BiqfilterX_q15_q15_q15.in file. The first values

are the coefficients of the filter and the rest of the values are the

input values. (See the example for declarations).

PM0014 Datenblatt(PDF) 44 Page - STMicroelectronics