PRODUCT SPECIFICATION

TMC2249A

10

REV. 1.0.2 7/6/00

Application Notes

The TMC2249A is a flexible signal and image processing building block with numerous user-selectable functions which

expand its usefulness. Table 2 clarifies the operation of the device, demonstrating the various feature available to the user and

the timing delays incurred.

Table 2. TMC2249A Operation Sequence

CASEN = 0, H=HIGH, L=LOW, “ms” indicates most significant output word (bits 23-8), “ls” indicates least significant word (bits

15-0). The appropriate enables for the indicated data are assumed, otherwise ‘-’ indicates that port not enabled. Note that the

output data summations including A(8)-D(8) is lost, since the output on cycle 13 is swapped to the LSW of S(12) on cycle 8.

In general, RND may be left high unless the ls output is to be used, as on line 8 above.

CLK ADEL A

11-0

BDEL B

11-0

CDEL C

11-0

DDEL D

11-0

NEG1 NEG2 CAS15-0 FT ACC RND SWAP

S15-0

1

0

A(1)

0

B(1)

0

C(1)

0

D(1)

L

L

0

L

L

H

H

—

2

0

A(2)

0

B(2)

0

C(2)

0

D(2)

L

H

0

L

L

H

H

—

3

0

A(3)

0

B(3)

0

C(3)

0

D(3)

H

L

0

L

L

L

H

—

4

0

A(4)

0

B(4)

0

C(4)

0

D(4)

L

L

CAS(4)

L

L

L

H

—

5

0

A(5)

0

B(5)

0

C(5)

0

D(5)

L

L

0

L

L

L

H

—

6

0

A(6)

0

B(6)

0

C(6)

0

D(6)

L

L

0

L

L

H

H

(A(1)

7

0

A(7)

0

B(7)

0

C(7)

0

D(7)

L

L

0

L

H

X

H

(A(2)

8

0

A(8)

0

B(8)

0

C(8)

0

D(8)

L

L

CAS(8)

H

L

L

L

(-A(3)

× B(3)+C(3) × D(3))ms

9

0

A(9)

0

B(9)

0

C(9)

0

D(9)

L

L

0

L

L

H

H

(A(4)

× B(4)+C(4) × D(4)+CAS(4))ms

10

(A(5)

× B(5)+C(5) × D(5)+CAS(8))ms

11

(A(6)

12

(A(7)

× B(7)+C(7) × D(7)+S(11))ms

13

(S(12))

ls

14

(A(9)

Digital Filtering

The input structure of the TMC2249A demonstrates great

versatility when all four multiplier inputs and the program-

mable delay registers are utilized.

Table 3 and Table 4 illlustrate how a direct-form symmetric

FIR filter of up to 32 taps can be implemented. By utilizing

the four input delay registers as pipelined storage banks, the

user can store up to 32 coefficient-data word pairs, split into

alternate "even" and "odd" halves. Two taps of the filter are

calculated on each clock, and the user then increments/decre-

ments the delay words (ADEL-DDEL). The sums of prod-

ucts are successively added to the global sum in the internal

accumulator.

Table 3. FIR Filtering with the TMC2249A—Initial Data Loading

Even Data

Odd Data

Coefficient

Storage

Register Position (Hex)

A

C

B

D

0

x(31)

x(30)

h(0)

h(1)

1

x(29)

x(28)

h(2)

h(3)

2

x(27)

x(26)

h(4)

h(5)

3

x(25)

x(24)

h(6)

h(7)

4

x(23)

x(22)

h(8)

h(9)

5

x(21)

x(20)

h(10)

h(11)

6

x(19)

x(18)

h(12)

h(13)

7

x(17)

x(16)

h(14)

h(15)

8

x(15)

x(14)

h(15)

h(14)

9

x(13)

x(12)

h(13)

h(12)

A

x(11)

x(10)

h(11)

h(10)

B

x(9)

x(8)

h(9)

h(8)

C

x(7)

x(6)

h(7)

h(6)

D

x(5)

x(4)

h(5)

h(4)

E

x(3)

x(2)

h(3)

h(2)

F

x(1)

x(0)

h(1)

h(0)