---
title: "Importance of coding and ASCII code"
subject: "Digital Logic"
chapter: 1
key: "semester_3/digital_logic:coding-importance-ascii"
source: https://www.bctengineer.com/q/semester_3/digital_logic/coding-importance-ascii
site: BCT Engineering
---

# Importance of coding and ASCII code

Digital Logic · Chapter 1: Introduction

- Asked in: 2080 Baisakh, 1+2 marks
- Video: [ASCII code Explained: Basics, Table, Conversion, and Examples](https://www.youtube.com/watch?v=gNA4GeIjJmM) — Engineering Funda
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/digital_logic/coding-importance-ascii
- Whole chapter: https://www.bctengineer.com/md/semester_3/digital_logic/chapter-1

## Question

What is importance of coding? Explain about ASCII code briefly.

## Short answer

Coding translates numbers, letters, and symbols into binary so digital systems can store, process, and transmit data reliably, also enabling error control and compression. ASCII is a 7-bit alphanumeric code for 128 characters: control codes (0-31,127), digits 48-57, uppercase 65-90, lowercase 97-122.

## Answer

#### Importance of coding
Digital systems understand only 0s and 1s, so numbers, letters and symbols must be **coded** into binary patterns. Coding allows data to be stored, processed and exchanged in a standard way, makes displays easy (BCD), reduces errors (Gray code, parity, Hamming code) and allows secure or compressed transmission.

#### ASCII code
**ASCII (American Standard Code for Information Interchange)** is a 7-bit alphanumeric code representing $2^7 = 128$ characters:
- 0–31 and 127: control characters (e.g. CR = 13, LF = 10).
- 48–57: digits '0'–'9'; 65–90: 'A'–'Z'; 97–122: 'a'–'z'.

Examples: 'A' = 65 = 100 0001 (41H); 'a' = 97 = 110 0001 (61H); '5' = 53 = 011 0101. An 8th bit is often used for parity or extended ASCII.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Why must data be coded for digital systems?
   A. They understand only decimal
   B. They need analog levels
   C. Coding increases voltage
   D. They understand only 0s and 1s
   Answer: D. Codes allow storing and exchanging data in a standard way. (Key point: Why code)

2. Which codes help reduce errors?
   A. Gray code, parity and Hamming code
   B. ASCII only
   C. BCD only
   D. Octal code
   Answer: A. These are the error-reducing codes. (Key point: Error reduction)

## Related in Digital Logic

- [ASCII code with examples](https://www.bctengineer.com/question.md?key=semester_3%2Fdigital_logic%3Aascii-code-explain) — Digital Logic, chapter 1, asked 2×
- [ASCII code and binary-to-Excess-3 converter](https://www.bctengineer.com/question.md?key=semester_3%2Fdigital_logic%3Aascii-binary-excess3-converter) — Digital Logic, chapter 1, asked 2×

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