PRODUCT SPECIFICATION
TMC2250A
4 x 2-Pixel Cascadeable Convolver
(Mode 11)
Similar to Mode 10, the 4 x 2 -Pixel convolver allows the use
to perform full-speed cubic convolution with only two
TMC2250A devices and the TMC2111A Pipeline Delay
Register to synchronize the cascade ports (see the Applica-
tions Discussion section).
As shown below, the column of input pixel data is automati-
cally shifted one location to the right through the two rows of
multiplier input registers on every clock in anticipation of
two new input data words, effectively sliding the convolu-
tional window over one column in an image plane.
Pixel data are side-loaded into ports A and B, multiplied by
the onboard coefficients, summed with the cascade input,
and half-LSB rounded to 16 bits. The four-cycle impulse
response emerges at the cascade output port 5 to 8 clock
cycles later. A new output word is available on every clock
cycle. Note that Multiplier KC2 is not used in this mode and
that its stored coefficient is ignored.
CASOUT(8)=
A(4)KA3(4)+A(3)KA2(3)+A(2)KA1(2)
+A(1)KB3(4)+B(4)KB3(4)+B(3)KB2(3)
+B(2)KB1(2)+B(1)KC1(2)+CASIN(5)
1
2
3
4
5
6
7
8
9
10
11
CLK
CWE
01
10
11
00
KA, KB, KC
DATA IN A, B
MODE
K_1
K_2
K_3
1.0
11
Q
8
CASIN
KA + KB
KA + KB
1 1
3
3
Q
CASOUT
8
KA + KB
KC + KC
1 3
2
2
Figure 7. 4 x 2-Pixel Convolver Impulse Response (Mode 11)
14
REV. 1.0.2 10/25/00
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
