PDSP16488A0 Mitel Networks Corporation, PDSP16488A0 Datasheet - Page 10

• Manufacturer Part Number: PDSP16488A0
• Description: Single Chip 2D Convolver with Integral Line Delays
• Manufacturer: Mitel Networks Corporation

10
Delay Compensation for Large Windows
which is implemented in an individual device. If necessary the partial
window must be padded with zero coefficients to become one of the
standard sizes. When constructing a large window it is necessary to
delay the expansion data inputs in order to compensate for growth
in the horizontal direction. Delays in the partial sums are also
necessary to compensate for the total pipeline delay needed to
produce the previous complete horizontal stripe.
A large window is composed of several partial windows each of
4 CLOCK
4 CLOCK
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
INPUT
LINE
LINE
LINE
0
0
0
D
0
D
ZERO
REG B3 = 0
D = 4 S(N 1) DEFINED BY REG D3:2
REG B3 = 1
DELAY = 0, DEFINED BY REG D3:2 = 00
REG B3 = 0
D = 4 S(N 1) DEFINED BY REG D3:2
REG D0 = 0
REG D0 = 0
REG D0 = 0
WIDTH = S
WIDTH = S
WIDTH = S
DELAYS
DELAYS
DELAYS
0
0
0
+
+
+
PDSP16488A
PDSP16488A
PDSP16488A
4 CLOCK
4 CLOCK
4 CLOCK
DELAY
DELAY
DELAY
Fig. 7 Multi-device delay paths
the expansion input must be delayed by the width of the partial
window, before it is added to the internal sum. Since partial
windows can only be 4 or 8 pixels wide, a delay of 4 or 8 pixel
clocks is needed. There is, however, an in-built delay of 4 pixels
in the inter device connection, and the PDSP16488A thus only
needs an option to delay the expansion input by an additional four
pixels.
Within each device in a horizontal stripe, apart from the first,
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
DELAYS
LINE
LINE
LINE
D
D
0
0
0
0
OR REG D0 = 1 IF S = 8
OR REG D0 = 1 IF S = 8
OR REG D0 = 1 IF S = 8
D = 4 S(N 1) DEFINED BY REG D3:2
REG B3 = 1
D = 4 S(N 1) DEFINED BY REG D3:2
REG B3 = 1
DELAY = 0, DEFINED BY REG D3:2 = 00
REG D0 = 0 IF S = 4,
REG B3 = 1
REG D0 = 0 IF S = 4,
REG D0 = 0 IF S = 4,
WIDTH = S
WIDTH = S
WIDTH = S
DELAYS
DELAYS
DELAYS
0/4
0/4
0/4
Nth PDSP16488A IN THE ROW
Nth PDSP16488A IN THE ROW
Nth PDSP16488A IN THE ROW
+
+
+
4 CLOCK
4 CLOCK
4 CLOCK
DELAY
DELAY
DELAY
OUTPUT