LMU112
DEVICES INCORPORATED
12 x 12-bit Parallel Multiplier
LMU112
12 x 12-bit Parallel Multiplier
DEVICES INCORPORATED
FEATURES
DESCRIPTION
The LMU112 is a high-speed, low
power 12-bit parallel multiplier built
using advanced CMOS technology.
The LMU112 is pin and functionally
which is loaded along with the B
operands. The operands are specified
to be in two’s complement format
when TC is asserted and unsigned
❑ 25 ns Worst-Case Multiply Time
❑ Low Power CMOS Technology
❑ Replaces Fairchild MPY112K
❑ Two’s Complement or Unsigned
compatible with Fairchilds’s MPY112K. magnitude when TC is deasserted.
Operands
Mixed mode operation is not allowed.
The A and B input operands are
❑ Three-State Outputs
loaded into their respective registers
on the rising edge of the separate
clock inputs (CLK A and CLK B).
Two’s complement or unsigned
magnitude operands are accommo-
For two’s complement operands, the
17 most significant bits at the output
of the asynchronous multiplier array
are shifted one bit position to the left.
This is done to discard the redundant
❑ Package Styles Available:
• 48-pin PDIP
• 52-pin PLCC, J-Lead
dated via the operand control bit (TC) copy of the sign-bit, which is in the
most significant bit position, and
extend the bit precision by one bit.
The result is then truncated to the 16
MSB’s and loaded into the output
register on the rising edge of CLK B.
LMU112 BLOCK DIAGRAM
A
11-0
TC
B11-0
12
A REGISTER
12
B REGISTER
The contents of the output register are
made available via three-state buffers
by asserting OE. When OE is de-
asserted, the outputs (R23-8) are in the
high impedance state.
CLK A
CLK B
24
FORMAT ADJUST
16
RESULT REGISTER
OE
16
R
23-8
Multipliers
08/16/2000–LDS.112-K
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