1.28.6.1 FLEXCOMx_USART_WriteThresholdSet Function

C

/* x = FLEXCOM instance number */

/* Ring buffer mode */

void FLEXCOMx_USART_WriteThresholdSet(uint32_t nBytesThreshold)

Summary

This API allows the application to set a threshold level on the number of free space available in the transmit buffer

Description

This API allows the application to set a threshold level on the number of free space available in the transmit buffer. Once the threshold is reached a notification is given to the application if it is enabled.

Precondition

FLEXCOMx_USART_Initialize must have been called for the associated FLEXCOM_USART instance.

Parameters

Param Description
nBytesThreshold Threshold value for free space in the transmit buffer after which a notification must be given

Returns

None

Example

uint8_t txBuffer[10];

volatile bool txThresholdEventReceived = false;

void usartWriteEventHandler(FLEXCOM_USART_EVENT event, uintptr_t context )
{
    txThresholdEventReceived = true;
}

//----------------------------------------------------------//

// Register a callback for write events
FLEXCOM0_USART_WriteCallbackRegister(usartWriteEventHandler, (uintptr_t) NULL);

// Set TX threshold - 10 or more bytes of free space in the transmit buffer
FLEXCOM0_USART_WriteThresholdSet(10);

// Enable notifications. Disable persistent notifications.
FLEXCOM0_USART_WriteNotificationEnable(true, false);

// First time transmit 5 bytes
FLEXCOM0_USART_Write((uint8_t*)txBuffer, 5);

if (txThresholdEventReceived == true)
{
    // Transmit buffer has space for 10 or more characters
    FLEXCOM0_USART_Write((uint8_t*)txBuffer, 10);
}

Remarks

None