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# 1.9 CRC-32 Generation

This example application demonstrates how to use the CRC peripheral to compute 32-bit Cyclic Redundancy Checksum (CRC).

## Description

The CRC unit provides support for calculating a CRC-8, CRC-16 and CRC-32 value on a user buffer or Flash memory without CPU intervention.

This example application computes the 32-bit CRC value for the polynomial (0x04C11DB7) using the CRC peripheral.

Once the hardware CRC is generated, it is validated using a software-calculated CRC value.

## Downloading and building the application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is apps/crc/crc32_generate/firmware.

To build the application, refer to the following table and open the project using its IDE.

Project Name | Description
--- | ---
pic32mm_usb_curiosity.X | MPLABX project for PIC32MM USB Curiosity board

## Setting up the hardware

The following table shows the target hardware for the application projects.

Project Name | Description
--- | ---
pic32mm_usb_curiosity.X | PIC32MM USB Curiosity board

### Setting up PIC32MM USB Curiosity Board

- To run the demo, the following additional hardware are required:
  - USB UART click board
- Connect micro USB cable to the 'USB1' connector on the board to the computer
- Install an USB UART click board on to the mikroBUS socket J4
- Connect mini USB cable between PC and the USB UART click board
  Note: Ensure that the series resistors on the mikroBUS headers are of value 0 Ohms

## Running the Application

1. Open the Terminal application (Ex.:Tera term) on the computer
2. Connect to the "USB to UART" COM port and configure the serial settings as follows:
   - Baud : 115200
   - Data : 8 Bits
   - Parity : None
   - Stop : 1 Bit
   - Flow Control : None
3. Build and Program the application project using its IDE
4. Following message is output on console:
   - Expected CRC Value for the polynomial (0x04C11DB7) is (0xcbf43926)
5. The LED indicates the success or failure:
   - LED1 is turned ON when the hardware CRC value matches with the software calculated CRC value

Following table provides LED name:

Board | LED Name
--- | ---
PIC32MM USB Curiosity board | LED1