LF2250
DEVICES INCORPORATED
12 x 10-bit Matrix Multiplier
(comprising of the summation of the
multiplications of the last nine data
inputs with their related coefficients)
becomes available (Table 5). The
CASIN term is also added to each
new output. The internal bus struc-
ture and pipeline delays allow new
input data to be added every cycle
while maintaining the structure of the
filtering operation. This addition of
new data every cycle produces the
effect of the convolution window
moving to the next pixel column.
4 x 2-Pixel Convolver — Mode 11
Using the A and B ports, input data is
loaded and multiplied by the on-
board coefficients. These products
are then summed with the CASIN
data and rounded to create the 16-bit
output. The cascade ports allow
multiple devices to be used together
for use with larger kernels. As with
Mode 10, each cycle results in a 16-bit
output created from the products and
summations performed.
T
ABLE
4.
CWE
1
-
0
00
01
10
11
C
OEFF
. R
EG
. U
PDATE
COEFFICIENT SET
Hold All Registers
KA1, KB1, KC1
KA2, KB2, KC2
KA3, KB3, KC3
DETAILS OF OPERATION
3 x 3 Matrix Multiplier — Mode 00
In this mode, all three input ports (A,
B, C) and all three output ports (X, Y,
Z) are utilized to implement a 3 x 3
matrix multiplication (triple dot
product). Each rounded 12-bit output
is the sum of all three input words
multiplied by the appropriate coeffi-
cients (Table 5). The pipeline latency
for this mode is five clock cycles.
Therefore, the sum of products will
be output five clock cycles after the
input data has been latched. New
output data is subsequently available
every clock cycle thereafter.
9-Tap FIR Filter — Mode 01
This mode utilizes the 12-bit A and B
data input ports as well as the 16-bit
CASIN port. The input data should
be presented to the A and B ports
simultaneously. The resulting 9-
sample response, which is half-LSB
rounded to 16 bits, begins after five
clock cycles and ends after 13 clock
cycles (Table 5). The pipeline latency
from the input of an impulse response
to the center of the output response is
nine clock cycles. The latency from
the CASIN port to the CASOUT port
is four clock cycles. New output data
is available every clock cycle.
3 x 3-Pixel Convolver — Mode 10
When configured in this mode, line
delayed data is loaded through the A,
B, and C input ports. During each
cycle, a new rounded 16-bit output
T
ABLE
5.
L
ATENCY
E
QUATIONS
3 x 3 Matrix Multiplier — Mode 00
X(n+4) = A(n)KA1(n) + B(n)KB1(n)
Y(n+4) = A(n)KA2(n) + B(n)KB2(n)
Z(n+4)
= A(n)KA3(n) + B(n)KB3(n)
+ C(n)KC1(n)
+ C(n)KC2(n)
+ C(n)KC3(n)
9-Tap FIR Filter — Mode 01
CASOUT(n+12)
= A(n+8)KA3(n+8) + A(n+7)KA2(n+7) + A(n+6)KA1(n+6)
+ B(n+5)KB3(n+8) + B(n+4)KB2(n+7) + B(n+3)KB1(n+6)
+ B(n+2)KC3(n+8) + B(n+1)KC2(n+7) + B(n)KC1(n+6)
+ CASIN(n+9)
3 x 3-Pixel Convolver — Mode 10
CASOUT(n+6)
= A(n+2)KA3(n+2) + A(n+1)KA2(n+1) + A(n)KA1(n)
+ B(n+2)KB3(n+2) + B(n+1)KB2(n+1) + B(n)KB1(n)
+ C(n+2)KC3(n+2) + C(n+1)KC2(n+1) + C(n)KC1(n)
+ CASIN(n+3)
4 x 2-Pixel Convolver — Mode 11
CASOUT(n+7)
= A(n+3)KA3(n+3) + A(n+2)KA2(n+2) + A(n+1)KA1(n+1)
+ A(n)KC3(n+3)
+ B(n+3)KB3(n+3) + B(n+2)KB2(n+2)
+ B(n+1)KB1(n+1) + B(n)KC1(n+1)
+ CASIN(n+4)
Video Imaging Products
4
08/16/2000–LDS.2250-L
LOGIC [ LOGIC DEVICES INCORPORATED ]
