www.fairchildsemi.com
TMC2246A
Image Filter
11 x 10 bit, 60 MHz
Features
Applications
• 60 MHz computation rate
• 60 MHz data and coefficient input
• Four 11 x 10-bit multipliers
• Fast pixel interpolation
• Fast image manipulation
• Image mixing and keying
• Individual data and coefficient inputs
• 25-Bit accumulator
• High-performance FIR filters
• Adaptive digital filters
• Fractional and integer two’s complement data formats
• Input and output data latches with user-configurable
enables
• One- and two-dimensional image processing
• Selectable 16-bit rounded output
• Internal 1/2 LSB rounding
• Available in 120-pin CPGA, PPGA, MPGA, or MQFP
Description
The TMC2246A is a video-speed convolutional array com-
posed of four 11 x 10 bit registered multipliers followed by a
summer and an accumulator. All eight multiplier inputs are
accessible to the user and may be updated every clock cycle
with integer or fractional two’s complement data. A pipe-
lined architecture, fully registered input and output ports,
and asynchronous three-state output enable control simplify
the design of complex systems.
The data or coefficient inputs to the multipliers may be held
over multiple clock cycles, providing storage for mixing and
filtering coefficients. The 25-bit internal accumulator path
allows two bits of cumulative word growth and may be inter-
nally rounded to 16 bits. Output data are updated every clock
cycle, or may be held under user control. All data inputs, out-
puts, and controls are TTL compatible and (except for the
three-state output enable) are registered on the rising edge of
CLK.
The TMC2246A is uniquely suited to performing pixel inter-
polation in image manipulation and filtering applications. As
a companion to the Fairchild Semiconductor TMC2301 and
TMC2302 Image Manipulation Sequencers, the TMC2246A
can execute a bilinear interpolation of an image (4-pixel ker-
nels) at real-time video rates. Larger kernels or other, more
complex, functions can be realized with no loss in performance
by utilizing multiple devices.
Logic Symbol
TMC2246A
Image Filter
D1
9-0
ENB1-4
ENSEL
ACC
C1
C2
C3
C4
10-0
D2
9-0
FSEL
With unrestricted access to all data and coefficient input
ports, the TMC2246A offers considerable flexibility in appli-
cations performing digital filtering, adaptive FIR filters, mix-
ers, and other similar systems requiring high-speed
processing.
10-0
S
15-0
D3
9-0
OCEN
OEN
CLK
10-0
D4
9-0
Fabricated in a submicron CMOS process, the TMC2246A
operates at a guaranteed clock rate of 60 MHz over the full
temperature and supply voltage ranges. It is pin- and func-
tion-compatible with Fairchild’s TMC2246, while providing
higher speed operation and lower power dissipation. It is
available in a 120 pin Plastic Pin Grid Array (PPGA), 120
pin Ceramic Pin Grid Array (CPGA), 120 lead MQFP to
PPGA (MPGA), and a 120 lead Metric Quad FlatPack
(MQFP).
10-0
REV. 1.0.3 9/11/00