PRODUCT SPECIFICATION
TMC2250A
9-Tap FIR Filter Mode (01)
The architecture for this configuration is shown in Figure 4.
The user loads the desired coefficient set, presents input data
to ports A and B simultaneously (most applications will wire
the A and B inputs together), and receives the resulting 9-
sample response, half-LSB rounded to 16 bits, 5 to 13 clock
cycles later. A new output data word is available every clock
cycle.
CASOUT(13) =
A(9)KA3(9)+A(8)KA2(8)+A(7)KA1(7)
+B(6)KB3(9)+B(5)KB2(8)+B(4)KB1(7)
+B(3)KC3(9)+B(2)KC2(8)+B(1)KC1(7)
+CASIN(10)
Latency: Impulse in to center of 9-tap response =9 registers.
Cascade In to Cascade Out=4 registers.
The figure shows that the input data are automatically right-
shifted by one position through the row of multiplier input
registers on every clock in anticipation of a new input data
word.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
CLK
CWE
01
10
11
KA, KB, KC
DATA IN A, B
K_1
K_2 K_3
1.0
01
MODE CONTROL
Q
CASIN
13
KA
KA
KA
KB
KB
KB
KC
KC
KC
Q
13
CASOUT
3
2
1
3
2
1
3
2
1
Figure 3. 9-Tap FIR Filter Impulse Response (Mode 01)
10
REV. 1.0.2 10/25/00
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
