Specifications
Multiplier Adder Sum Mode
Figure 3-11: One Sum of Two 18 x 19 Multipliers with One Variable Precision DSP Block for Cyclone V
Devices
Input Register Bank
Result[37..0]
dataa_y0[18..0]
dataa_x0[17..0]
19
18
Variable-Precision DSP Block
datab_y1[18..0]
datab_x1[17..0]
19
18
38
Multiplier
Multiplier
Adder
+/-
Chainout adder or
accumulator
SUB_COMPLEX
Output Register Bank
+
x
x
18 x 18 Multiplication Summed with 36-Bit Input Mode
Cyclone V variable precision DSP blocks support one 18 x 18 multiplication summed to a 36-bit input.
Use the upper multiplier to provide the input for an 18 x 18 multiplication, while the bottom multiplier is
bypassed. The datab_y1[17..0] and datab_y1[35..18] signals are concatenated to produce a 36-
bit input.
Figure 3-12: One 18 x 18 Multiplication Summed with 36-Bit Input Mode for Cyclone V Devices
Input Register Bank
Result[36..0]
dataa_y0[17..0]
dataa_x0[17..0]
18
18
Variable-Precision DSP Block
datab_y1[35..18]
datab_y1[17..0]
18
18
37
Multiplier
Adder
Chainout adder or
accumulator
SUB_COMPLEX
Output Register Bank
x
+/-
+
Altera Corporation
Variable Precision DSP Blocks in Cyclone V Devices
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3-15
Multiplier Adder Sum Mode
CV-52003
2013.05.06