Altera Integer Arithmetic IP - Manual (Page 58)

The following settings are applied in this mode:
• The width of the
dataa[]
input (
WIDTH_A
) must be less than or equals to 17 bits
• The width of the
datab[]
input (
WIDTH_B
) must be less than or equals to 17 bits
• The number of multipliers must be set to 2
This mode is expressed in the following equation.
The following shows the pre-adder square mode of two multipliers.
Figure 6-5: Pre-adder Square Mode
a0
b0
a1
b1
Mult0
Mult1
result
+/-
+/-
Pre-adder Constant Mode
In this mode, one multiplier operand derives from the input port, and the other operand derives from the
internal coefficient storage. The coefficient storage allows up to 8 preset constants. The coefficient
selection signals are
coefsel[0..3]
.
The following settings are applied in this mode:
• The width of the
dataa[]
input (
WIDTH_A
) must be less than or equals to 27 bits
• The width of the coefficient input must be less than or equals to 27 bits
• The
datab[]
port must be disconnected
This mode is expressed in the following equation.
The following figure shows the pre-adder constant mode of a multiplier.
UG-01063
2014.12.19
Pre-adder Constant Mode 6-5
ALTERA_MULT_ADD (Multiply-Adder) Altera Corporation
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