520 - 64 - 7

11

The filter coefficients are shown in Figure 10. The timing is verysimilar to that of the even-symmetric case.

ASYMMETRIC FILTER

The GF9101 can be used as a 24-tap asymmetric filter by

configuring it the same way as the even-symmetric case.

The difference is in the memory locations since the

asymmetric case uses 24 different coefficients, i.e. two sets

of filter coefficients. The filter coefficients and the memory

locations are shown in Table 10.

The timing diagram is shown in Figure 11. The data flow

diagrams are shown in Figures 11a and 11b.

TABLE 9: Configuration Word for a 24-tap Symmetric Filter

BIT

NO.

CONFIG.

WORD

DESCRIPTION

01

11

2

0

One register delay

30

4

0

24-tap filter, connect the outputs of

DATA_A_OUT to the inputs of DATA_B_IN.

5

X

Depending on the loading mode

6

X

See Table 1

NOTE

3. Bits 0 and 1 should have the same value for a 23 or 24 tap filter

TABLE 10:Internal RAM Address & Contents for a 24-tap

Asymmetric Filter

COEF_ADDR (6-0)

MEMORY CONTENTS

Second set of 12 coefficients, C23 —> C12