Hello,
I'm trying to run UART in Loop Back mode on an MPC5777M evaluation board. I have UART working properly in normal mode, but I want to use higher baud rates (>3 Mbits/s) and thought that the loop back would be a good way to test it.
I set the LBKM bit in LINCR1 in INIT mode and make other configurations as I did with regular UART. I use the following functions:
void TransmitCharacter(uint8_t ch)
{
// address of LINFLEX_0.BDRL.B.DATA0
unsigned char *pTX = (unsigned char *)&LINFlexD_2.BDRL.R + 3;
*pTX = ch; /* write character to transmit buffer */
while (1 != LINFlexD_2.UARTSR.B.DTFTFF) {}; /* Wait for data transmission completed flag */
LINFlexD_2.UARTSR.R = 0x0002; /* clear the DTF flag and not the other flags */
}
void ReadCharacter (void)
{
while (1 != LINFlexD_2.UARTSR.B.DRFRFE) {} /* Wait for data reception completed flag */
while (1 != LINFlexD_2.UARTSR.B.RMB) {} /* Wait for Release Message Buffer */
rx_data = (uint8_t)LINFlexD_2.BDRM.B.DATA4; /* get the data */
/* clear the DRF and RMB flags by writing 1 to them */
LINFlexD_2.UARTSR.R = 0x0204;
}
void uart_loopback(uint8_t TransmitDataBuffer, uint32_t txSize)
{
int j = 0;
for (j=0; j< txSize; j++)
{
TransmitCharacter(TransmitDataBuffer[j]);
ReadCharacter();
}
}
The transmit part is happening fine but receive does not happen at all.
Please help me find where I am going wrong.
Thanks!
