https://github.com/embetech-official/crc
Lightweight CRC library
https://github.com/embetech-official/crc
c cpp library utility
Last synced: 4 months ago
JSON representation
Lightweight CRC library
- Host: GitHub
- URL: https://github.com/embetech-official/crc
- Owner: embetech-official
- License: mit
- Created: 2023-12-29T10:43:25.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2026-01-15T14:14:35.000Z (6 months ago)
- Last Synced: 2026-01-15T18:15:44.937Z (6 months ago)
- Topics: c, cpp, library, utility
- Language: C
- Homepage:
- Size: 41 KB
- Stars: 0
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
Awesome Lists containing this project
README
# CRC
[](https://github.com/embetech-official/crc/actions/workflows/on_push.yml)
[](https://app.codacy.com/gh/embetech-official/crc/dashboard?utm_source=gh&utm_medium=referral&utm_content=&utm_campaign=Badge_grade)
## Overview
CRC is a small C library for calculating 8/16/32-bit checksums using standard, well-known polynomials. It provides simple, dependency-free functions and optional LUT-accelerated variants.
## Supported Polynomials
- CRC8-ITU (Poly 0x07, Init 0x00, no input/output bit reflection, XorOut 0x55)
- CRC16-CCITT BLUETOOTH CCITT-TRUE V-41-LSB KERMIT (Poly 0x1021, Init 0x0000, input/output bit reflection, XorOut 0x0000)
- CRC16-MODBUS (Poly 0x8005, Init 0xFFFF, input/output bit reflection, XorOut 0x0000)
- CRC32-POSIX/cksum (Poly 0x04C11DB7, Init 0x00000000, no input/output bit reflection, XorOut 0xFFFFFFFF)
## Core APIs
Headers:
- `embetech/crc8.h`
- `embetech/crc16.h`
- `embetech/crc32.h`
Version helper:
- `CRC_GetVersionString()` in `embetech/crc.h`
Representative functions:
- CRC-8 (ITU): `CRC8_ITU_Init`, `CRC8_ITU_UpdateUsingFormula`, `CRC8_ITU_UpdateUsingLut`, `CRC8_ITU_Finalize`
- CRC-16 CCITT: `CRC16_CCITT_Init`, `CRC16_CCITT_UpdateUsingFormula`, `CRC16_CCITT_UpdateUsingLut`, `CRC16_CCITT_Finalize`
- CRC-16 MODBUS: `CRC16_MODBUS_Init`, `CRC16_MODBUS_UpdateUsingFormula`, `CRC16_MODBUS_UpdateUsingLut`, `CRC16_MODBUS_Finalize`
- CRC-32 POSIX/cksum: `CRC32_CKSUM_Init`, `CRC32_CKSUM_UpdateUsingFormula`, `CRC32_CKSUM_UpdateUsingLut`, `CRC32_CKSUM_Finalize`
## Installation
This project uses CPM.cmake for source consumption and also supports installable CMake package metadata.
Using CPM.cmake in your project:
```cmake
# Download CPM.cmake (pin version as needed)
file(DOWNLOAD
https://github.com/cpm-cmake/CPM.cmake/releases/download/v0.42.0/CPM.cmake
${CMAKE_BINARY_DIR}/cmake/CPM.cmake
EXPECTED_HASH SHA256=2020b4fc42dba44817983e06342e682ecfc3d2f484a581f11cc5731fbe4dce8a
)
include(${CMAKE_BINARY_DIR}/cmake/CPM.cmake)
# Add crc (pin to a released tag or major stream)
CPMAddPackage("gh:embetech-official/crc@2")
add_executable(app main.c)
target_link_libraries(app PRIVATE embetech::crc)
```
Include headers via:
```c
#include
#include
#include
#include
```
## Build
Use CMake Presets (Ninja Multi-Config) for a streamlined workflow:
```sh
cmake --workflow --preset native-gcc
```
The workflow configures, builds Debug, runs tests, and installs Debug+Release.
## Options
- `CRC_TESTS` (default: ON if top-level): Builds unit tests (GoogleTest via CPM).
- `CRC_DOC` (default: ON if top-level): Builds Doxygen docs.
- `CRC_EXAMPLES` (default: ON if top-level): Builds example targets.
- `CRC_INSTALL` (default: ON): Enables install targets and generates CMake package config files.
Configure-time overrides, for example:
```sh
cmake --preset native-gcc -D CRC_TESTS=ON -D CRC_DOC=OFF -D CRC_EXAMPLES=ON
```
## Dependencies
- Runtime: none.
- Tests: `google/googletest` (fetched via CPM when tests are enabled).
- Optional: if `embetile` is available, an additional API file is compiled and linked automatically.
## Usage Example
Minimal example computing CRC-8, CRC-16 CCITT, and CRC-32 checksums:
```c
#include
#include
#include
int main(void) {
unsigned char data[100] = {0};
// CRC-8 ITU (formula or LUT variant)
uint8_t c8 = CRC8_ITU_Init();
c8 = CRC8_ITU_UpdateUsingLut(data, sizeof(data), c8);
c8 = CRC8_ITU_Finalize(c8);
// CRC-16 CCITT
uint16_t c16 = CRC16_CCITT_Init();
c16 = CRC16_CCITT_UpdateUsingLut(data, sizeof(data), c16);
c16 = CRC16_CCITT_Finalize(c16);
// CRC-32 POSIX/cksum
uint32_t c32 = CRC32_CKSUM_Init();
c32 = CRC32_CKSUM_UpdateUsingLut(data, sizeof(data), c32);
c32 = CRC32_CKSUM_Finalize(c32);
(void)c8; (void)c16; (void)c32;
return 0;
}
```
## Versioning
`CRC_GetVersionString()` returns the library version string. When built at the repository top-level, a short git commit id is appended (e.g., `X.Y.Z+abcdef12`).
## Contributing
Issues and PRs are welcome. Please use the provided presets to build, run tests, and keep changes focused.