#Uart serial protocol how to
#Uart serial protocol serial
#Uart serial protocol manual

#define SYSTICK_TMR_RELOAD_VAL ((SYSTEM_CLOCK_FREQ / SYTICK_TIME_FREQ) - 1UL) // 48000 - 1 #define SYTICK_TIME_FREQ (SYTICK_TIME_INTERVAL * 1000) // 1000 Khz This gives SBR value in UART0_BDL as 0x38 and SBR value in UART0_BDH asВ 0x1. As described above, we have selected 48Mhz as the clock source for UART0 module.Д«R = 48000000 / (16 * 9600) = 312 (0x138). This is the clock source for Baud Rate Generator. The next parameter in formula is Baud Clock. Lets select OSR value as 16 (the default one). It is defined in UART0_CR4 control register. OSR is defined as Over Sampling Ratio configurable for UART receiver between 4x and 32x. The formula used for baud rate calculation is:Д«R is combination of SBR from UART0_BDL control register and SBR from UART0_BDH control register. However higher baud rate can increase burden on your processor due to faster Rx/Tx Interrupt trigger rate).ДЄs specified in the memory map of UART0, there are two control registers used for baud rate selection. We will use 9600 baud rate for our application (Note: Higher the Baud Rate, less is the time required for data transmission/reception.

#Uart serial protocol serial

There are standard baud rates which you can select for serial communication like 4800, 9600, 19200, 48000 etc. The next important thing that comes in UART communication is selection of Baud Rate, which specifies the numbers of signals transmitted per second over serial wires. Make sure you enable PORTA clock before writing anything to PORTA control registers. So configure bits 10-8 (MUX) of PORTA_PCR1 and PORTA_PCR2 registers with value 2 (010). (UART0_RX and UART0_TX) is used is used for PTA1 and PTA2 pins. Again by looking into table defined for I/O pins (see above screenshots), you will notice вЂњAlternative 2вЂќ So you have to choose correct alternative for PTA1 and PTA2 pins.

#Uart serial protocol manual

Go to the section вЂњ Port Control and Interrupt (PORT)вЂќ from your user reference manual and search for the section вЂњPort Control Register n (PORTx_PCRn).вЂќ As you can see below, the I/O pins are multiplexed with different peripherals (Alternative). So first letsВ configure your PTA1 and PTA2 I/O pins for UART communication. So you have to use UART0 module for serial communication. In user reference manual you can see PTA1 and PTA2 are multiplexed with UART0_RX and UART0_TX pins. But wait, your freedom KL25Z board says PTA1 and PTA2 pin are used as a serial Port pins. So now you have multiple options for selecting UART pins. Similarly, Pin 20, 21, 22 and 23 of PORTE are multiplexed and can be used as Transmit and Receive pins for UART0 and UART2 modules respectively. Pin 0 and 1 of PORTE are multiplexed and can be used as Transmit and Receive pins for UART1 module. For example, in section вЂњPinoutвЂќ you can see how pins are multiplexed. UART Transmit and Receive pins are multiplexed with other digital IO pins. These are 3 independent UART modules and you can use them to create 3 serial interfaces working in parallel. In the user reference manual of KL25Z, there are 2 sections provided for UART, one is UART0 and other is UART1/UART2. So create a new project by copying your previous project folder and renaming the folder to something else.

#Uart serial protocol how to

With this assumption I will go ahead and explain how to write a application for UART serial communication. I assume you have some background on serial communication and UART layer. UART can be used as a physical layer in standard or custom communication protocols like MODBUS. UART is not a protocol neither it is a standard, it is just a physical layer with Transmit and Receive serial data lines. UART is a standard physical layer used across all Microcontrollers for serial data communication. UART stands for Universal Asynchronous Receiver Transmitter. We will use in-built UART module of Microcontroller as a physical layer for Serial Data Communication. In this tutorial we will develop a Serial Communication Interface to Transmit and Receive data to and from remote device e.g.