LINFlex Initialization

[bengtandersson]

Hi!

I have a strange problem when initializing the LINFlex controller in MPC5602B. It seems like whenever doing this or changing the baudrate  setting in the controller it requires a delay before the controller can be used. A small delay of 50 ms seems to be enough.

Here is the initialization code:

void InitUart(const tUartId uartNr, const tBaudRate baud, tBuffer *const rxBuffer, tBuffer *const txBuffer)
{
tUartSettings * uart = &uarts[uartNr];


// configuration of LINLFEX periphial
uart->linflex->LINCR1.B.SLEEP = 0; // Disable LINFLEX sleep mode

uart->linflex->LINCR1.B.INIT = 1; // LINFLEX in init mode

// UART settings
uart->linflex->UARTCR.B.UART = 1; // Run LINFLEX in UART mode
uart->linflex->UARTCR.B.TDFL = 0; // 1byte buffer
uart->linflex->UARTCR.B.RDFL = 0; // 1byte buffer
uart->linflex->UARTCR.B.RXEN = 1; // rx enable
uart->linflex->UARTCR.B.TXEN = 1; // tx enable
uart->linflex->UARTCR.B.PCE = 0; // no Parity
uart->linflex->UARTCR.B.WL = 1; // 8bit data

// Baudrate configuration
uart->linflex->LINIBRR.B.DIV_M = baudMantissa[baud];
uart->linflex->LINFBRR.B.DIV_F = baudFraction[baud];

// Enable interupts
uart->linflex->LINIER.B.DRIE=1;
uart->linflex->LINIER.B.DTIE=1;

// start Linflex
uart->linflex->LINCR1.B.INIT = 0; // LINFLEX in run mode

//TODO: £R1 £F4 Check if I/Os needs to be configured as fast.
// Configure I/O pins pins
SIU.PCR[uart->txPcr].B.OBE = setBit; // Set pin as output
SIU.PCR[uart->txPcr].B.PA = uart->txPadAlterntaiveMode;

SIU.PCR[uart->rxPcr].B.IBE = setBit; // Set pin as input
SIU.PCR[uart->rxPcr].B.WPE = setBit; // Enable weak pulling device
SIU.PCR[uart->rxPcr].B.WPS = setBit; // Set to pull up

uart->txBuffer = rxBuffer;
uart->rxBuffer = txBuffer;

// Install interupt handlers
INTC_InstallINTCInterruptHandler(UartRxIntHandler,uart->rxInt,8);
INTC_InstallINTCInterruptHandler(UartTxIntHandler,uart->txInt,8);


uart->status = idle;
}

Here is the routine changing the baudrate. 

void ChangeBaudRate(const tUartId uartNr, const tBaudRate baud)
{
tUartSettings * uart = &uarts[uartNr];

uart->linflex->LINCR1.B.INIT = 1; // LINFLEX in init mode

// Baudrate configuration
uart->linflex->LINIBRR.B.DIV_M = baudMantissa[baud];
uart->linflex->LINFBRR.B.DIV_F = baudFraction[baud];

// start Linflex
uart->linflex->LINCR1.B.INIT = 0; // LINFLEX in run mode

}

Regards

Bengt

[PetrS]

Hi,

I have tested attached code on the MPC5604B EVB and I do not see any issue after initialization. Bytes are normally transmitted into PC. On-board transceiver is used. When I used external RS232 to USB cable, then sometimes first few bytes was corrupted.

Could this be a reason? What is your HW and how do you test the case?

BR, Petr

[bengtandersson]

HI!

This might be the reason to my problem. Is "few bytes corrupted" really OK?

I'm communicating with an onboard radio module (Digi XBee 868 LP). The "test" is simply when I try to send something to the radio directly after InitUart() this will not work. But when inserting a delay of 50 ms between InitUart() and the first "send" on UART it will work fine. See example from my code below.

 InitUart(radioUart, baud9600, &radioRxBuffer, &radioTxBuffer);
 
 // A small delay here seems to be necessary
 DelayMs(delayAfterBaudRateChange);
 
 // The radio should now be ready to communicate at speed 9600 Baud so a change to API mode is made
 ChangeFromTransparentToApiMode();

Best Regards

Bengt