Accumulator Multiplier

This is a Sequential Multiplier.

Process

1. Initialize $R=00\dots 0$ as a Shift Register
2. You multiply each bit of $A$ by $B$, add it to $R$
3. Shift $R$ to the left by $1$ (It does this every clock cycle)
4. Repeat until each bit of $A$ is multiplied and added

Block Diagram

Pros & Cons

Pros

• Cheaper to build

Cons

• Time complexity is $O(N)$