Quick Start Guide for the PARC driver

This is the quick start guide for the SAM4L Parallel Capture (PARC) Driver, with step-by-step instructions on how to configure and use the driver for a specific use case.

The use cases contain several code fragments. The code fragments in the steps for setup can be copied into a custom initialization function, while the steps for usage can be copied into, e.g. the main application function.

Use Cases

• PARC Basic Use Case

PARC Basic Use Case

This use case demonstrates how to use the PARC module on SAM4L. In this use case the PARC module is configured as:

• Capture every byte
• Sample the data bus on the rising edge of the PCCK input clock
• Sample data regardless of the levels of PCEN1 and PCEN2
• 8-bit data width

Setup Steps

Prerequisites

This module requires the following service:

• System clock (sysclk)

Setup Code Example

Add the following to the main loop or a setup function:

    struct parc_module module_inst;
    struct parc_config config;

    // Get default configuration
    parc_get_config_defaults(&config);

    // Initialize PARC.
    parc_init(&module_inst, PARC, &config);
    
    // Enable the PARC
    parc_enable(&module_inst);
    
    // Start capture.
    parc_start_capture(&module_inst);

Basic Setup Workflow

1. Initialize and configure PARC:

       // Get default configuration
       parc_get_config_defaults(&config);

       // Initialize PARC.
       parc_init(&module_inst, PARC, &config);

2. Enable the PARC module and start capture:

       // Enable the PARC
       parc_enable(&module_inst);
       
       // Start capture.
       parc_start_capture(&module_inst);

PARC Basic Usage

Basic Usage Code

We can poll the data ready status and then read it once capture has finished:

 uint32_t captured_data;

 while (!parc_is_data_ready(&module_inst)) {
     }
 parc_read(&module_inst, &captured_data); 

We can enable the data ready interrupt and install a callback function to perform a custom task:

 parc_register_callback(&module_inst,
     (parc_callback_t)parc_complete_callback, PARC_CALLBACK_DATA_READY);
 parc_enable_interrupts(&module_inst, PARC_INTERRUPT_DRDY);
 parc_enable_callback(&module_inst, PARC_CALLBACK_DATA_READY);
 parc_start_capture(&module_inst);

 // The callback function example.
 static void parc_complete_callback(
     struct parc_module *const module)
 {
   callback_data_ready = true;
   parc_read(module, &captured_data);
 }