TMC2249A Datasheet, PDF (1/18 Pages) Fairchild Semiconductor – Digital Mixer 12 x 12 Bit, 60 MHz

TMC2249A
Digital Mixer
12 x 12 Bit, 60 MHz
www.fairchildsemi.com
Features
• 60 MHz input and computation rate
• Two 12-bit multipliers
• Separate data and coefficient inputs
• Independent, user-selectable pipeline delays of 1 to 16
clocks on all input ports
• Separate 16-bit input port allows cascading or addition of
a constant
• User-selectable rounded output
• Internal 1/2 LSB rounding of products
• Fully registered, pipelined architecture
• Available in 120-Pin CPGA, PPGA, MPGA or MQFP
Applications
• Video switching
• Image mixing
• Digital signal modulation
• Complex frequency synthesis
• Digital filtering
• Complex arithmetic functions
Description
The TMC2249A is a high-speed digital arithmetic circuit
consisting of two 12-bit multipliers, an adder and a cascade-
able accumulator. All four multiplier inputs are simulta-
neously accessible to the user, and each includes a user-
programmable pipeline delay of up to 16 clocks in length.
The 24-bit adder/subtractor is followed by an accumulator
and 16-bit input port which allows the user to cascade multi-
ple TMC2249As. A new 16-bit accumulated output is avail-
able every clock, up to the maximum rate of 60 MHz. All
inputs and outputs are registered except the three-state out-
put enable, and all are TTL compatible.
The TMC2249A utilizes a pipelined, bus-oriented structure
offering significant flexibility. Input register clock enables
and programmable input data pipeline delays on each port
offer an adaptable input structure for high-speed digital
systems. Following the multipliers, the user may perform
addition or subtraction of either product, arithmetic rounding
to 16 bits, and accumulation and summation of products with a
cascading input. The output port allows access to all 24 bits of
the internal accumulator by switching between overlapping
least and most-significant 16-bit words, and a three-state out-
put enable simplifies connection to an external system bus.
Logic Symbol
A11-0
ADEL3-0
ENA
B11-0
BDEL3-0
ENB
C11-0
CDEL3-0
ENC
D11-0
DDEL3-0
END
CAB15-0
TMC2249A
Digital Mixer
Delay
1-16
Delay
1-16
Delay
1-16
Delay
1-16
CLK
NEG1
NEG2
SWAP
OE
ACC
S15-0
RND
FT
CASEN
The TMC2249A has numerous applications in digital pro-
cessing algorithms, from executing simple image mixing and
switching, to performing complex arithmetic functions and
complex waveform synthesis. FIR filters, digital quadrature
mixers and modulators, and vector arithmetic functions may
also be implemented with this device.
Fabricated in a submicron CMOS process, the TMC2249A
operates at guaranteed clock rates of up to 60 MHz over the
full temperature and supply voltage ranges. It is pin- and
function-compatible with Fairchild’s TMC2249, while pro-
viding higher speed operation and lower power dissipation. It
is available in a 120 pin Ceramic Pin Grid Array (CPGA),
120 pin Plastic Pin Grid Array (PPGA), 120 lead MQFP to
PPGA package (MPGA), and a 120 lead Metric Quad Flat-
Pack (MQFP).
REV. 1.0.2 7/6/00