Intermediate
30 min

Generate high-frequency clock output with ICS501 and PIC18F97J94

Phase-Locked Loop (PLL) mechanism

PLL Click with Fusion for PIC v8

Published Aug 09, 2023

Click board™

PLL Click

Dev Board

Fusion for PIC v8

Compiler

NECTO Studio

MCU

PIC18F97J94

Generate highly stable and coherent high-frequency signals for applications requiring tight synchronization and minimal phase noise

A

A

Hardware Overview

How does it work?

PLL Click is based on the ICS501, a LOCO™ PLL clock multiplier, from Integrated Device Technology. This IC uses the Phase-Locked Loop to provide a high-frequency clock output, deriving input from a much cheaper, standard fundamental frequency crystal oscillator. Besides the onboard crystal oscillator fixed at 12MHz, it is possible to select the signal from the mikroBUS™ PWM pin as the clock input source. To select the desired multiplication factor, the states of the two input pins, S0 and S1, are routed to the mikroBUS™ pins RST and AN, respectively. These pins can be set to a HIGH or LOW logic state or disconnected (by tri-stating the MCU pins). The combination of these pins states will set the PLL

Click to a specific multiplier. The Output Enable (OE) pin of the ICS501 is used to turn off the output clock by setting it to a LOW logic level. It will additionally set the clock output pin in high impedance (Hi-Z) mode, allowing complete disconnection and no influence on the rest of the circuit, which is useful for experimenting and prototyping purposes. This pin is internally pulled to a HIGH logic level. The OE pin is routed to the CS pin of the mikroBUS™. PLL Click is equipped with two onboard SMD jumpers. The SMD jumper labeled as the VCC SEL is used to select the operating voltage level, consequently limiting the amplitude of the clock output signal with respect to the selected voltage. The other SMD jumper

labeled as the OSC SEL chooses the clock input source between the onboard 12MHz crystal oscillator or the external clock signal. The output signal is routed through the onboard SMA connector, which provides a secure connection and good signal shielding. PLL Click has a library containing functions for all the MIKROE compilers (mikroBASIC, mikroPASCAL, and mikroC). Although relatively easy to control, the library offers comprehensive functions that make the code readable and easy to use. The included example application demonstrates the use of these functions, and it can be used as a reference for custom projects.

PLL click hardware overview image

Features overview

Development board

Fusion for PIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different PIC, dsPIC, PIC24, and PIC32 MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, Fusion for PIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the Fusion for PIC v8 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB

HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet are also included, including the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options (graphical and character-based LCD). Fusion for PIC v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

Fusion for PIC v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

3862

Used MCU Pins

mikroBUS™ mapper

Multiplier Adjustment
PA3
AN
Multiplier Adjustment
PJ4
RST
Output Enable
PL1
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
External Clock Source
PG4
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

PLL click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Fusion for PIC v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN Access MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

This Click board can be interfaced and monitored in two ways:

  • Application Output - Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.

Software Support

Library Description

This library contains API for PLL Click driver.

Key functions:

  • pll_set_clock_output - This function settings clock output

  • pll_set_pll_4x - This function settings PLL x4

  • pll_set_pll_6x - This function settings PLL x6

Open Source

Code example

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

/*!
 * \file 
 * \brief PLL Click example
 * 
 * # Description
 * This app sets PLL signals.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes device.
 * 
 * ## Application Task  
 * Every 2 seconds, the PLL increases the input clock from min (x2) to max (x8) level.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "pll.h"

// ------------------------------------------------------------------ VARIABLES

static pll_t pll;
static log_t logger;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    pll_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.
    pll_cfg_setup( &cfg );
    PLL_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    pll_init( &pll, &cfg );
    pll_set_clock_output( &pll, PLL_CLOCK_ENABLE );
}

void application_task ( void )
{
    log_printf( &logger, " PLL level: x2\r\n\n" );
    pll_set_pll_2x( &pll );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " PLL level: x3\r\n\n" );
    pll_set_pll_3x( &pll );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " PLL level: x3.125\r\n\n" );
    pll_set_pll_3_125x( &pll );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " PLL level: x4\r\n\n" );
    pll_set_pll_4x( &pll );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " PLL level: x5\r\n\n" );
    pll_set_pll_5x( &pll );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " PLL level: x5.3125\r\n\n" );
    pll_set_pll_5_3125x( &pll );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " PLL level: x6\r\n\n" );
    pll_set_pll_6x( &pll );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " PLL level: x6.25\r\n\n" );
    pll_set_pll_6_25x( &pll );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " PLL level: x8\r\n\n" );
    pll_set_pll_8x( &pll );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

// ------------------------------------------------------------------------ END

Additional Support

Resources

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