4–6
Chapter 4: Embedded Multipliers in the Cyclone III Device Family
Operational Modes
1
You can also use embedded multipliers of the Cyclone III device family to implement
multiplier adder and multiplier accumulator functions, in which the multiplier
portion of the function is implemented using embedded multipliers, and the adder or
accumulator function is implemented in logic elements (LEs).
18-Bit Multipliers
You can configure each embedded multiplier to support a single 18 × 18 multiplier for
input widths of 10 to 18 bits.
shows the embedded multiplier configured to support an 18-bit multiplier.
Figure 4–3. 18-Bit Multiplier Mode
signa
signb
aclr
clock
ena
Data A [17..0]
D
ENA
Q
Data Out [35..0]
D
Q
ENA
CLRN
CLRN
Data B [17..0]
D
ENA
Q
CLRN
18
×
18 Multiplier
Embedded Multiplier
All 18-bit multiplier inputs and results are independently sent through registers. The
multiplier inputs can accept signed integers, unsigned integers, or a combination of
both. Also, you can dynamically change the
signa
and
signb
signals and send these
signals through dedicated input registers.
9-Bit Multipliers
You can configure each embedded multiplier to support two 9 × 9 independent
multipliers for input widths of up to 9 bits.
Cyclone III Device Handbook
Volume 1
December 2011 Altera Corporation
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