/**
*
* This function does a minimal test on the UART device using the low-level
* driver macros and functions. This function sends data and expects to receive
* the data thru the UART. A physical loopback must be done by the user with the
* tranmit and receive signals of the UART.
*
* @param UartBaseAddress is the base address of the UARTNS550 device
* and is the XPAR_<UARTNS550_instance>_BASEADDR value from
* xparameters.h.
*
* @return XST_SUCCESS if successful, XST_FAILURE if unsuccessful.
*
* @note None.
*
****************************************************************************/
int XUartNs550_LowLevelExample(u32 UartBaseAddress)
{
int Index;
/*
* Initialize the send buffer bytes with a pattern to send and the
* the receive buffer bytes to zero
*/
for (Index = 0; Index < TEST_BUFFER_SIZE; Index++) {
SendBuffer[Index] = Index + '0';
RecvBuffer[Index] = 0;
}
/*
* Set the baud rate and number of stop bits
*/
XUartNs550_SetBaud(UartBaseAddress, UART_CLOCK_HZ, UART_BAUDRATE);
XUartNs550_SetLineControlReg(UartBaseAddress, XUN_LCR_8_DATA_BITS);
/*
* Enable the FIFOs for 16550 mode since the defaults is NO FIFOs
*/
XUartNs550_WriteReg(UartBaseAddress, XUN_FCR_OFFSET, XUN_FIFO_ENABLE);
/*
* Send the entire transmit buffer
*/
for (Index = 0; Index < TEST_BUFFER_SIZE; Index++) {
XUartNs550_SendByte(UartBaseAddress, SendBuffer[Index]);
}
/*
* Receive the entire buffer's worth. Note that the RecvByte function
* blocks waiting for a character
*/
for (Index = 0; Index < TEST_BUFFER_SIZE; Index++) {
RecvBuffer[Index] = XUartNs550_RecvByte(UartBaseAddress);
}
/*
* Check the receive buffer data against the send buffer and verify the
* data was correctly received
*/
for (Index = 0; Index < TEST_BUFFER_SIZE; Index++) {
if (SendBuffer[Index] != RecvBuffer[Index]) {
return XST_FAILURE;
}
}
return XST_SUCCESS;
}
