Clock Gen click

Clock Gen Click offers an ideal replacement for crystals, crystal oscillators, VCXOs, phase-locked loops (PLLs), and fanout buffers in cost-sensitive applications. This click features the Si5351A from Silicon Labs, an I2C configurable clock generator based on a PLL + high resolution MultiSynth fractional divider architecture which can generate any frequency up to 200 MHz on each of its outputs with 0 ppm error.

click Product page

Click library

• Author : MikroE Team
• Date : jun 2020.
• Type : I2C type

Software Support

We provide a library for the ClockGen Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly form compilers IDE(recommended way), or downloaded from our LibStock, or found on mikroE github account.

Library Description

This library contains API for ClockGen Click driver.

Standard key functions :

• Config Object Initialization function.

  void clockgen_cfg_setup ( clockgen_cfg_t *cfg );

• Initialization function.

  CLOCKGEN_RETVAL clockgen_init ( clockgen_t ctx, clockgen_cfg_t cfg );

• Click Default Configuration function.

  void clockgen_default_cfg ( clockgen_t *ctx );

Example key functions :

• This function sets clock divider

  void clockgen_set_frequency ( clockgen_t *ctx, uint8_t clk_num, uint8_t pll_num, uint32_t freq );

• This function sets pll.

  void clockgen_setup_pll ( clockgen_t *ctx, uint8_t pll, uint8_t mult, uint32_t num );

• This function sets clock frequency on specific clock.

  void clockgen_setup_multisyinth ( clockgen_t *ctx, uint8_t clk_num, uint32_t divider, uint32_t num );

Examples Description

Clock Gen Click represent a replacement for crystals, crystal oscillators, VCXOs, phase-locked loops (PLLs), and fanout buffers. This click features an I2C configurable clock generator based on a PLL + high resolution MultiSynth fractional divider architecture which can generate any frequency up to 200 MHz with 0 ppm error. The chip on click is capable of generating synchronous or free-running non-integer related clock frequencies at each of its outputs (CLK0, CLK1, and CLK2), enabling one device to synthesize clocks for multiple clock domains in a design.

The demo application is composed of two sections :

Application Init

Configures device to default function that enables clock 0 and disables all others.

void application_init ( void )
{
    log_cfg_t log_cfg;
    clockgen_cfg_t cfg;

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, "---- Application Init ----" );


    //  Click initialization.

    clockgen_cfg_setup( &cfg );
    CLOCKGEN_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    clockgen_init( &clockgen, &cfg );

    clockgen_default_cfg( &clockgen );

    Delay_ms ( 500 );
}

Application Task

Changes 4 different frequency in span of 5 seconds.

void application_task ( void )
{
    clockgen_set_frequency( &clockgen, CLOCKGEN_CLOCK_0, CLOCKGEN_PLLA, 1 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    clockgen_set_frequency( &clockgen, CLOCKGEN_CLOCK_0, CLOCKGEN_PLLA, 3 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    clockgen_set_frequency( &clockgen, CLOCKGEN_CLOCK_0, CLOCKGEN_PLLA, 10 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    clockgen_set_frequency( &clockgen, CLOCKGEN_CLOCK_0, CLOCKGEN_PLLA, 5 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
} 

The full application code, and ready to use projects can be installed directly form compilers IDE(recommneded) or found on LibStock page or mikroE GitHub accaunt.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.ClockGen

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all Mikroelektronika compilers, or any other terminal application of your choice, can be used to read the message.