/**
*
* This function sends one byte using the device. This function operates in
* polled mode and blocks until the data has been put into the TX FIFO register.
*
* @param BaseAddress contains the base address of the device.
* @param Data contains the byte to be sent.
*
* @return None.
*
* @note None.
*
*****************************************************************************/
void XUartPs_SendByte(u32 BaseAddress, u8 Data)
{
/*
* Wait until there is space in TX FIFO
*/
while (XUartPs_IsTransmitFull(BaseAddress));
/*
* Write the byte into the TX FIFO
*/
XUartPs_WriteReg(BaseAddress, XUARTPS_FIFO_OFFSET, Data);
}
/*
*
* This function sends a buffer that has been previously specified by setting
* up the instance variables of the instance. This function is an internal
* function for the XUartPs driver such that it may be called from a shell
* function that sets up the buffer or from an interrupt handler.
*
* This function sends the specified buffer in either polled or interrupt
* driven modes. This function is non-blocking.
*
* In a polled mode, this function only sends as much data as the TX FIFO
* can buffer. The application may need to call it repeatedly to send the
* entire buffer.
*
* In interrupt mode, this function starts the sending of the buffer, if not
* the entire buffer has been sent, then the interrupt handler continues the
* sending until the entire buffer has been sent. A callback function, as
* specified by the application, will be called to indicate the completion of
* sending.
*
* @param InstancePtr is a pointer to the XUartPs instance
*
* @return The number of bytes actually sent
*
* @note None.
*
*****************************************************************************/
u32 XUartPs_SendBuffer(XUartPs *InstancePtr)
{
u32 SentCount = 0U;
u32 ImrRegister;
/*
* If the TX FIFO is full, send nothing.
* Otherwise put bytes into the TX FIFO unil it is full, or all of the
* data has been put into the FIFO.
*/
while ((!XUartPs_IsTransmitFull(InstancePtr->Config.BaseAddress)) &&
(InstancePtr->SendBuffer.RemainingBytes > SentCount)) {
/*
* Fill the FIFO from the buffer
*/
XUartPs_WriteReg(InstancePtr->Config.BaseAddress,
XUARTPS_FIFO_OFFSET,
((u32)InstancePtr->SendBuffer.
NextBytePtr[SentCount]));
/*
* Increment the send count.
*/
SentCount++;
}
/*
* Update the buffer to reflect the bytes that were sent from it
*/
InstancePtr->SendBuffer.NextBytePtr += SentCount;
InstancePtr->SendBuffer.RemainingBytes -= SentCount;
/*
* If interrupts are enabled as indicated by the receive interrupt, then
* enable the TX FIFO empty interrupt, so further action can be taken
* for this sending.
*/
ImrRegister =
XUartPs_ReadReg(InstancePtr->Config.BaseAddress,
XUARTPS_IMR_OFFSET);
if (((ImrRegister & XUARTPS_IXR_RXFULL) != (u32)0) ||
((ImrRegister & XUARTPS_IXR_RXEMPTY) != (u32)0)||
((ImrRegister & XUARTPS_IXR_RXOVR) != (u32)0)) {
XUartPs_WriteReg(InstancePtr->Config.BaseAddress,
XUARTPS_IER_OFFSET,
ImrRegister | (u32)XUARTPS_IXR_TXEMPTY);
}
return SentCount;
}
/**
*
* This function does a minimal test on the UART device using the hardware
* interface.
*
* @param UartBaseAddress is the base address of the device
*
* @return XST_SUCCESS if successful, XST_FAILURE if unsuccessful
*
* @note None.
*
**************************************************************************/
int UartPsEchoExample(u32 UartBaseAddress)
{
int Index;
u32 Running;
u8 RecvChar;
u32 CntrlRegister;
CntrlRegister = XUartPs_ReadReg(UartBaseAddress, XUARTPS_CR_OFFSET);
/*
* Enable TX and RX for the device
*/
XUartPs_WriteReg(UartBaseAddress, XUARTPS_CR_OFFSET,
((CntrlRegister & ~XUARTPS_CR_EN_DIS_MASK) |
XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN));
/*
* 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';
}
/*
* Send the entire transmit buffer.
*/
for (Index = 0; Index < TEST_BUFFER_SIZE; Index++) {
/*
* Wait until there is space in TX FIFO
*/
while (XUartPs_IsTransmitFull(UartBaseAddress));
/*
* Write the byte into the TX FIFO
*/
XUartPs_WriteReg(UartBaseAddress, XUARTPS_FIFO_OFFSET,
SendBuffer[Index]);
}
Running = TRUE;
while (Running) {
/*
* Wait until there is data
*/
while (!XUartPs_IsReceiveData(UartBaseAddress));
RecvChar = XUartPs_ReadReg(UartBaseAddress,
XUARTPS_FIFO_OFFSET);
/* Change the capitalization */
if (('a' <= RecvChar) && ('z' >= RecvChar)) {
// Convert the Capital letter to a small.
RecvChar = RecvChar - 'a' + 'A';
}
else if (('A' <= RecvChar) && ('Z' >= RecvChar)) {
// Convert the small letter to a Capital.
RecvChar = RecvChar - 'A' + 'a';
}
else if (CHAR_ESC == RecvChar) {
Running = FALSE;
}
/* Echo the character back */
XUartPs_WriteReg(UartBaseAddress, XUARTPS_FIFO_OFFSET,
RecvChar);
}
return XST_SUCCESS;
}