1. CprE 583 – Reconfigurable Computing
Multiplication
Shift and add operations
Need N bit adder, M cycles
42 = Multiplicand (N bits)
x 10 = x Multiplier (M bits)
000000
Partial products
420 = Product (N+M bits)
CprE 583 – Reconfigurable Computing
September 5, 2006

2. CprE 583 – Reconfigurable ComputingX3 X2 X1 X0
Array Multiplier Y0
Area – N x M cells
Delay – O(N+M) Y1 X3 X2 X1 X0 + + + + Y2 X3 X2 X1 X0 + + + + Y3 X3 X2 X1 X0 + + + + Z2 Z1 Z0
September 5, 2006
CprE 583 – Reconfigurable Computing

3. CprE 583 – Reconfigurable ComputingX3 X2 X1 X0
Carry-Save Y0 Y1 X3 X2 X1 X0 + + + + Y2 + + + +
There's one critical path here - along the right-hand side and across the bottom. Y3 + + + + Z2 Z1 Z0
CprE 583 – Reconfigurable Computing
September 5, 2006