LF3338
DEVICES INCORPORATED
8-Bit Vertical Digital Image Filter
LF3338
DEVICES INCORPORATED
8-Bit Vertical Digital Image Filter
DESCRIPTION
The
LF3338
is a lower cost version of
the 12-bit LF3330 and is suited for
multimedia and special effects systems,
projectors, plasma display panels, scan
converters, set-top boxes, and other
consumer applications.
This device filters digital images in
the vertical dimension at real-time
video rates. Input data is 8 bits and
coefficient data is 12 bits and both are
in two’s complement format. The
output is also in two’s complement
format and may be rounded to 16 bits.
The filter is an 8-tap FIR filter with all
required line buffers contained on-
chip. The line buffers can store video
lines with lengths from 4 to 3076
pixels. Multiple LF3338s can be
cascaded together to create larger
vertical filters.
Due to the length of the line buffers,
interleaved data can be fed directly
into the device and filtered without
separating the data into individual
data streams. The number of inter-
leaved data sets that the device can
handle is limited only by the length of
the on-chip line buffers. If the inter-
leaved video line has 3076 data values
or less, the filter can handle it.
The LF3338 contains enough on-board
memory to store 256 coefficient sets.
The LF Interface
TM
allows all 256
coefficient sets to be updated within
vertical blanking.
Selectable 16-bit data output with
user-defined rounding and limiting
minimizes the constraints put on
coefficient sets for various filter
implementations.
FEATURES
u
u
u
u
u
83 MHz Data Rate
8-bit Data and 12-bit Coefficients
Supports Interleaved Data Streams
Cascadable for More Filter Taps
Seven 3K x 8-bit, Dynamic Program-
mable Two-Mode Line Buffers
u
On-board Memory for 256
Coefficient Sets
u
LF Interface
TM
Allows All 256
Coefficient Sets to be Updated
Within Vertical Blanking
u
Selectable 16-bit Data Output with
User-Defined Rounding and
Limiting
u
Separate Input Port for Odd and
Even Field Filtering
u
u
u
u
8 Filter Taps
3.3 Volt Power Supply
5 Volt Tolerant I/O
Purchase Description
LF3338 B
LOCK
D
IAGRAM
8
DIN
7-0
3K LINE BUFFER
3K LINE BUFFER
3K LINE BUFFER
8-TAP VERTICAL FILTER
256 COEFFICIENT SET STORAGE
32
8
VB
7-0
3K LINE BUFFER
ROUND
SELECT
LIMIT
CIRCUITRY
OED
16
DOUT
15-0
3K LINE BUFFER
3K LINE BUFFER
3K LINE BUFFER
8
COUT
7-0
OEC
Video Imaging Products
1
04/06/1999–LDS.3338-B
LOGIC [ LOGIC DEVICES INCORPORATED ]
