Last Updated on August 21, 2023 by Mayank Dham

In the world of computer arithmetic, division is a fundamental operation that plays a crucial role in various applications, ranging from numerical computations to digital signal processing. Among the various division algorithms, the Non-Restoring Division Algorithm for unsigned integers stands out as an efficient and intriguing method. This algorithm is used to perform division without the need for restoring intermediate remainders, offering a streamlined approach to achieving accurate quotient results. In this article, we delve into the mechanics of the Non-Restoring Division Algorithm, exploring its principles, advantages, and step-by-step execution. By understanding this algorithm, we gain insights into the inner workings of modern digital systems and gain a deeper appreciation for the algorithms that power our computational world.

## What is the Non-Restoring Division Algo for unsigned Integer?

The Non-Restoring Division Algorithm is a method used to perform division operations on unsigned integers without relying on restoring intermediate remainders. It’s an iterative approach that approximates the quotient and updates the remainder in each iteration, leading to an accurate division result.

## Here’s an overview of how the Non-Restoring Division Algorithm works:

**Initialization:**

Load the dividend and divisor into separate registers.

Initialize a counter to keep track of the number of iterations.

**Comparison and Adjustment:**

- Compare the divisor with the accumulated remainder.
- If the remainder is greater than or equal to the divisor, subtract the divisor from the remainder and set a "borrow" flag to 0.
- If the remainder is less than the divisor, set the borrow flag to 1.

**Shift:**

Left shift the accumulated remainder by one position.

**Update Borrow Flag:**

If the borrow flag is 1, add the divisor to the remainder.

**Iteration:**

Repeat steps 2 to 4 for a fixed number of iterations (usually equal to the number of bits in the operands) or until the counter reaches the desired value.

**Quotient Formation:**

The quotient is formed from the counter value.

**Final Adjustment:**

After the iterations, if the remainder is greater than or equal to the divisor, subtract the divisor from the remainder to get the final remainder.

**Result:**

The quotient and remainder obtained from the algorithm represent the result of the division operation.

The Non-Restoring Division Algorithm avoids the need to restore intermediate remainders by adjusting the remainder directly based on comparisons and borrow flags. It’s particularly useful in hardware implementations where parallel processing is possible due to the fixed number of iterations.

Let’s discuss the Flowchart for Non-Restoring Division Algo for unsigned integer.

## FlowChart for Non-Restoring Division Algo for unsigned Integer

Now, let’s delve into the sequential stages of the non-restoring division algorithm, which are outlined below:

**Step 1:** Initialization involves loading pertinent values into registers. Specifically, register A is initialized with 0, register M holds the Divisor, register Q retains the Dividend, and N designates the number of bits in the dividend.

**Step 2:** Proceeding to the next phase, we assess the sign bit of register A.

**Step 3:** Should this bit within register A be 1, we shift the AQ value to the left and execute A = A + M. In contrast, if the bit is 0, we again shift the AQ value leftward but perform A = A – M. In the latter case, the 2’s complement of M is added to register A, and the outcome replaces A.

**Step 4:** A subsequent verification of the sign bit of A is carried out.

**Step 5:** When the sign bit within register A is 1, Q[0] is set to 0. Conversely, if the bit is 0, Q[0] is set to 1. Here, Q[0] signifies the least significant bit of Q.

**Step 6:** Afterward, N is decremented, acting as a counter in the process.

**Step 7:** If N equals 0, the progression advances to the ensuing step. Otherwise, a return to step 2 is warranted.

**Step 8:** If the sign bit of register A is 1, we proceed with A = A + M.

**Step 9:** Concluding the algorithm, in this final step, register A holds the remainder, while register Q embodies the quotient.

Let’s see an example that will explain the process for Non-Restoring Division Algo for unsigned Integer.

## Example for Non-Restoring Division Algo for unsigned Integer

In this example, we will perform a Non-Restoring Division algorithm with the help of an Unsigned integer.

N | M | A | Q | Action |
---|---|---|---|---|

4 | 00011 | 00000 | 1011 | Begin |

00011 | 00001 | 011_ | Shift left AQ | |

00011 | 11110 | 011_ | A = A – M | |

3 | 00011 | 11110 | 0110 | Q[0] = 0 |

00011 | 11100 | 110_ | Shift left AQ | |

00011 | 11111 | 110_ | A = A + M | |

2 | 00011 | 11111 | 1100 | Q[0] = 0 |

00011 | 11111 | 100_ | Shift left AQ | |

00011 | 00010 | 100_ | A = A +M | |

1 | 00011 | 00010 | 1001 | Q[0] = 1 |

00011 | 00101 | 001_ | Shift left AQ | |

00011 | 00010 | 001_ | A = A – M | |

0 | 00011 | 00010 | 0011 | Q[0] = 1 |

Consequently, register A holds the remaining value 2, while register Q holds the quotient 3.

**Conclusion**

The Non-Restoring Division Algorithm showcases the elegance of algorithmic design in computer arithmetic. Its ability to perform division operations efficiently, with predictable latency and potential for parallelism, makes it a valuable tool in modern digital systems. Understanding the mechanics of this algorithm not only sheds light on division techniques but also provides insights into the optimization of hardware and software implementations. As we continue to push the boundaries of computational efficiency, algorithms like the Non-Restoring Division Algorithm remain instrumental in achieving high-performance calculations across various domains.

## FAQ on Non-Restoring Division Algo for unsigned Integer

**Q1: What is the Non-Restoring Division Algorithm?**

The Non-Restoring Division Algorithm is a technique used to perform division operations on unsigned integers without relying on the traditional process of restoring intermediate remainders. Instead, this algorithm involves a series of steps that iteratively approximate the quotient and adjust the remainder, resulting in an accurate division result.

**Q2: How does the Non-Restoring Division Algorithm work?**

The algorithm involves the following main steps:

**Initialization:**Load the dividend and divisor into separate registers.- Comparison: Compare the divisor with the accumulated remainder.
**Shift and Adjustment:**Shift the accumulated remainder and update it based on the comparison result.**Iteration:**Repeat the comparison and adjustment process until a certain number of iterations is reached.**Quotient Formation:**The quotient is formed from the number of iterations and a final adjustment.

**Q3: What are the advantages of the Non-Restoring Division Algorithm?**

The Non-Restoring Division Algorithm offers several advantages, including:

**Faster Execution:**As compared to restoring algorithms, non-restoring algorithms often require fewer iterations, resulting in faster division operations.**Parallelism:**The algorithm lends itself to parallel execution, making it suitable for hardware implementation.**Predictable Latency:**The number of iterations is fixed, leading to predictable latency, which is crucial for real-time applications.

**Q4: Are there any drawbacks or limitations to this algorithm?**

While the Non-Restoring Division Algorithm has its advantages, it also comes with some limitations, such as:

**Complexity:**The algorithm requires additional steps to manage the non-restoring approach, potentially leading to more intricate circuitry or code.**Initial Divisor Shift:**The initial shift of the divisor can introduce a delay before the algorithm begins the division process.