Master the art of precise timing with CS2200-CP and STM32F091RC
Clock frequency synthesizer
Published Feb 26, 2024
Click board™
Clock Gen 4 Click
Dev. board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
Integrate an advanced clock generator into your solution and witness the transformative impact on timing control
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Hardware Overview
How does it work?
Clock Gen 4 Click is based on the CS2200-CP, an analog PLL architecture comprised of a Delta-Sigma fractional-N frequency synthesizer from Cirrus Logic. The Delta-Sigma fractional-N frequency synthesizer has a high resolution for Input/Output clock ratios, low phase noise, a wide range of output frequencies, and the ability to tune to a new frequency quickly. This synthesizer multiplies the timing reference clock by the value of N to generate a stable and low-jitter PLL clock on the connector labeled PLL Clock. This Click board™ also has another connector marked as AUX Clock that outputs a buffered version of one of the input/output clocks or a status signal, depending on register configuration. The analog PLL-based frequency synthesizer uses a low-jitter timing reference clock
as a time and phase reference for the internal voltage-controlled oscillator (VCO). The phase comparator compares the fractional-N divided clock with the original timing reference and generates a control signal filtered by the internal loop filter to generate the VCO’s control voltage that sets its output frequency. The Delta-Sigma modulator modulates the loop integer divide ratio to get the desired fractional ratio between the reference clock and the VCO output. This allows fast lock times for various output frequencies without external filter components. Clock Gen 4 Click provides the possibility of using both I2C and SPI interfaces with a maximum frequency of 100kHz for I2C and 6MHz for SPI communication. The selection can be performed by positioning SMD jumpers labeled
COMM SEL to an appropriate position. Note that all the jumpers must be placed on the same side, or the Click board™ may become unresponsive. While the I2C interface is selected, the CS2200-CP allows the choice of the least significant bit (LSB) of its I2C slave address. This can be done by using the SMD jumper labeled as ADDR SEL. This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.
Features overview
Development board
Nucleo-64 with STM32F091RC MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
256
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
32768
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32F091RC MCU as your development board.
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.
2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.
3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.
Software Support
Library Description
This library contains API for Clock Gen 4 Click driver.
Key functions:
void clockgen4_dev_ctl ( uint8_t dev_ctl );- Function is used to write to Device Control register in order to apply settings.void clockgen4_dev_cfg ( uint8_t dev_cfg );- Function is used to write to Device Configuration 1 register in order to apply settings.uint32_t clockgen4_set_ratio ( float ratio );- Function is used to set the ratio between the output signal and the input clock.
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 main.c
* @brief ClockGen4 Click example
*
* # Description
* This example demonstrates the use of Clock Gen 4 click which is based on CS2200-CP for changing the channel clock. The CS2200-CP is an extremely
* versatile system clocking device that utilizes a programmable phase lock loop. The CS2200-CP is based on an analog PLL architecture and this
* architecture allows for frequency synthesis and clock generation from a stable reference clock. The CS2200-CP supports both I²C and SPI for full software control.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes I2C and SPI, sets CS pin as output and starts to write log, applies default settings and adjusted ratio to obtain a frequency.
*
* ## Application Task
* Clock Gen 4 click is used in this example to generate and change the clock on the output channel.
*
* @author Jelena Milosavljevic
*
*/
#include "board.h"
#include "log.h"
#include "clockgen4.h"
static clockgen4_t clockgen4;
static log_t logger;
uint8_t com_itfc = 0;
void application_init ( void ){
log_cfg_t log_cfg; /**< Logger config object. */
clockgen4_cfg_t clockgen4_cfg; /**< Click config object. */
/**
* 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 " );
Delay_ms ( 100 );
log_printf( &logger, "---------------------" );
log_printf( &logger, " Clock Gen 4 Click " );
log_printf( &logger, "---------------------" );
// Click initialization.
clockgen4_cfg_setup( &clockgen4_cfg );
CLOCKGEN4_MAP_MIKROBUS( clockgen4_cfg, MIKROBUS_1 );
err_t init_flag = clockgen4_init( &clockgen4, &clockgen4_cfg );
if ( ( I2C_MASTER_ERROR == init_flag ) || ( SPI_MASTER_ERROR == init_flag ) ) {
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
clockgen4_default_cfg ( &clockgen4 );
log_info( &logger, " Application Task " );
Delay_ms ( 100 );
}
void application_task ( void ){
clockgen4_dev_ctl ( &clockgen4, CLOCKGEN4_AUX_OUT_DIS | CLOCKGEN4_CLK_OUT_EN );
log_printf( &logger, " PLL Clock \r\n" );
log_printf( &logger, " output enabled! \r\n" );
log_printf( &logger, "---------------------\r\n" );
Delay_ms ( 1000 );
clockgen4_dev_ctl ( &clockgen4, CLOCKGEN4_AUX_OUT_EN | CLOCKGEN4_CLK_OUT_DIS );
log_printf( &logger, " AUX Clock \r\n" );
log_printf( &logger, " output enabled! \r\n" );
log_printf( &logger, "---------------------\r\n" );
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
