TMS570LS1224: Issue of internal loopback test for UART poll mode

Hello,

Please call sciReceive(sciREG, len, rxBuffer) before starting the RTI counter.

If sciReceive() is not called, the SCI ISR uses LEN=0 to read the incoming chars. 

Thanks again. I'll check it.

regards

Datïan

Hi, QJ.

To make sure my modification is identical to your suggestion, I attach the modification as below. Left side is original. The red circle is added part. I'm afraid the program will be blocked by sciReceive.

regards

Datïan

Hello Ditian,

I am sorry. This way is good for interrupt mode, not for polling mode. For polling mode, please check the RX flag before reading the data. This is an example:

for (i=0; i<len; i++)

{

while ((UART->FLR & 0x4) == 4);
while ((UART->FLR & (uint32)SCI_TX_INT) == 0U);
UART->TD = text[i];

while ((UART->FLR & (uint32)SCI_RX_INT) == 0U);
rxdata[i] = (UART->RD & 0x000000FFU);

};

for(i=0; i<len; i++){

if(rxdata[i] != text[i])
err++;

}

Hello QJ,

Many thanks for your sample code. It works indeed, but not solves my issue. What I concern is test of sending and receiving multiple character, not only character by character .

In sci.c I found the functions of sciSend and sciReceive. According to the names, I think the functions of sciSend and sciReceive are for multiple characters. The description of sciReceive function also shows it is possible to call sciReceive in poll mode. But I failed to do that.

regards

Datïan

Hi Datian,

In my example code, len is the number of characters you want to tx and rx.

if using single buffer mode, and TX and RX on the same device, there is no way to send multiple characters first, then read them later.

If you want to transfer multiple chars, please consider to use multi-buffer mode.

Thank you QJ.

Would you like to give me some references about multi-butter mode or uart for TMS570LS1224 in more detail?

kind regards

Datïan

Hello,

Please read 29.2.5 SCI Multi-Buffered Mode in TRM SPNU515C.pdf

Hi QJ,

Many thanks for your information. Sometimes I can not find what I want, although I believe it might be somewhere.

regards

Datïan

Hi Datian,

You don't have to use multi-buffered mode. The code you gave you is good enough to check if the received char is the same as the transmitted data.

QJ Wang said:

Hi Datian,

You don't have to use multi-buffered mode. The code you gave you is good enough to check if the received char is the same as the transmitted data.

Hi QJ,

Thank you very much for you thinking it good enough. I wrote this code in order to verify using uart to send and receiving mulptiple characters. This code proves it failed. The most sad thing is I don't know why it failed. Could you help me to find out why or give me some demo for modifying it ? Please have a look at the new added annotations of if-else block in while(1) in main function, which might make you comprehend my intention and sufferning.

kind regards

Datïan

Hello QJ,

Many thanks. I will change my design. Would you like to teach me how to use uart in ISR mode, like receiving multiple characters by calling sciReceive without waiting for characters received, making ISR function handles the receiving matter which is trigered by interrupt signal ?

warm regards

Datïan

Hello QJ,

Thank you very much. I'll try it immediately.

kind regards

Datïan

Hello QJ,
I want to use a global variable modified in ISR function of receiving for controlling while loop in main function. Where could I find the ISR function ?
regards
Datïan

Hello QJ,

Thank you very much for your picture. I'm afraid I missed something. What I find about ISR in SCI.c is about LIN, but not sci. I know the pins of rx/tx of SCI and HET1_6/13 are multiplexed, and I know the channel 13 is for LIN or SCI2 as well. I don't know which channel of VIM is for SCI.

best regards

Datïan

Hello QJ,

I use linsci to continue my test for uart ISR mode. The received characters are "fgefgef", "gefgefg", "fgefgef". The expected characters might be "abcdefg". My test code is as below. Is there something wrong or I missed this time ?

/* USER CODE BEGIN (0) */
/* USER CODE END */

/* Include Files */

#include "sys_common.h"

/* USER CODE BEGIN (1) */
#include "gio.h"
#include "mibspi.h"
#include "sci.h"
#include "rti.h"
/* USER CODE END */

/** @fn void main(void)
*   @brief Application main function
*   @note This function is empty by default.
*
*   This function is called after startup.
*   The user can use this function to implement the application.
*/

/* USER CODE BEGIN (2) */
unsigned char txBuffer[7]={'a','b','c','d','e','f','g'};
unsigned char rxBuffer[7];
int len=7;
int myRx = 0;

/* USER CODE END */

int main(void)
{
/* USER CODE BEGIN (3) */
    gioInit();
    mibspiInit();//PIN_CLK for output; PIN_CS3 for input
    sciInit();

    while(sciIsIdleDetected(scilinREG));
    sciEnableLoopback(scilinREG, Digital_Lbk);

    /* Enable interrupt */
    _enable_IRQ();

    sciReceive(scilinREG, len, rxBuffer);

    rtiInit();
    /* Enable RTI compare 0 notification */
    rtiEnableNotification(rtiNOTIFICATION_COMPARE0);
    /* Start counter */
    rtiStartCounter(rtiCOUNTER_BLOCK0);

    while(1)
    {
        gioToggleBit(gioPORTB, 2);

        while(myRx==0);

        if(myRx==1)
        {
            myRx=0;

            if(0==gioGetBit(mibspiPORT3, PIN_CS3))  //Changing the condition online to confirm received characters in rxBuff are wrong online.  pin9@J5, 0:pin2@J3 or pin1@J5, 1:pin1@J2
            {
                if(rxBuffer[0]=='a'&&rxBuffer[1]=='b'&&rxBuffer[2]=='c'&&rxBuffer[3]=='d'&&rxBuffer[4]=='e'&&rxBuffer[5]=='f'&&rxBuffer[6]=='g')
                {
                    gioToggleBit(gioPORTB, 1);
                    rxBuffer[0]=0;
                    rxBuffer[1]=0;
                    rxBuffer[2]=0;
                    rxBuffer[3]=0;
                    rxBuffer[4]=0;
                    rxBuffer[5]=0;
                    rxBuffer[6]=0;
                    sciReceive(scilinREG, len, rxBuffer);
                }
            }
            else
            {
                if((rxBuffer[0]=='f'&&rxBuffer[1]=='g'&&rxBuffer[2]=='e'&&rxBuffer[3]=='f'&&rxBuffer[4]=='g'&&rxBuffer[5]=='e'&&rxBuffer[6]=='f')
                 ||(rxBuffer[0]=='g'&&rxBuffer[1]=='e'&&rxBuffer[2]=='f'&&rxBuffer[3]=='g'&&rxBuffer[4]=='e'&&rxBuffer[5]=='f'&&rxBuffer[6]=='g')
                 ||(rxBuffer[0]=='e'&&rxBuffer[1]=='f'&&rxBuffer[2]=='g'&&rxBuffer[3]=='e'&&rxBuffer[4]=='f'&&rxBuffer[5]=='g'&&rxBuffer[6]=='e')) //Characters were observed by setting break points at line of while(1) after next else
                {
                    gioToggleBit(gioPORTB, 1);
                    rxBuffer[0]=0;
                    rxBuffer[1]=0;
                    rxBuffer[2]=0;
                    rxBuffer[3]=0;
                    rxBuffer[4]=0;
                    rxBuffer[5]=0;
                    rxBuffer[6]=0;
                    sciReceive(scilinREG, len, rxBuffer);
                }
                else
                    while(1);
            }

        }
    }
/* USER CODE END */

    return 0;
}


/* USER CODE BEGIN (4) */
void rtiNotification(uint32 notification)
{
    sciSend(scilinREG, len, txBuffer);
}

void sciNotification(sciBASE_t *sci, uint32 flags)
{
    if(flags==SCI_RX_INT)
    {
        gioToggleBit(mibspiPORT3, PIN_CLK);//pin7@J2, 0:pin2@J3, indicating receiving
        myRx=1;
    }
}
/* USER CODE END */

kind regards

Datïan

Hello QJ,

Thank you very much for your help. With your support and information, this issue is finally solved. I changed my design. I use timer ISR to trigger sending. Sending function is called by a while loop inside main function in poll mode I think. Receving function works in interrupt mode. Then it works.

 warm regards

Datïan

Good news, Datian.