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Reading into SBUF is SLOW

Mayuri Ghosalkar 


# include <stdio.h>

# include <aduc842.h>

#pragma registerbank(2)



void sendmoduleinit(void);
void InitByte_Char (volatile unsigned long);
void print2uart_hex(int);
void displaytemp1(void);

void displaycal(void);
void sendremaining(void);
volatile unsigned char moduleinit;



int ucRxChar1;

int check_sum;
int check_sum_tx;



void main()

{

EA = 1;
ES = 1;

T3CON = 0x83;

T3FD = 0x2D;

SCON = 0x50;


if(ucRxChar1 == 0xCC)

{
sendmoduleinit();
}
if (ucRxChar1 == 0xFA && ucRxChar1 == 0xFA && ucRxChar1 == 0x05 && ucRxChar1 == 0xAA && ucRxChar1 == 0x2F)


{displaytemp1();

}

if (ucRxChar1 == 0x05 && ucRxChar1 == 0xAB)


{displaycal();

}



}

void ISR_sc(void) interrupt 4 using 2

{
if (TI==1) {
TI=0; //clear interrupt
}
else {
ucRxChar1 = SBUF; //put value on pins
RI=0; //clear interrupt
}



/*REN = 1;
while(RI == 0)
                {}

                        ucRxChar1 = SBUF;
                                RI = 0;
*/
}

void sendmoduleinit(void)
{

                                        check_sum = (0xF5 ^ 0xF5 ^ 0x06 ^ 0xFF ^ 0xFF);

                                        check_sum_tx = (check_sum & 0x7F);

                                InitByte_Char(0xF5);
                                InitByte_Char(0xF5);

                                InitByte_Char(0x06);
                                InitByte_Char(0xFF);


                                InitByte_Char(0xFF);

                            print2uart_hex(check_sum_tx);


        }

void InitByte_Char (volatile unsigned long result)

{       REN = 0;
SBUF = result;

                while (TI == 0)
                         {

                         }
                 TI = 0;
 REN = 1;
}
void print2uart_hex(int chksum)
{  REN = 0;

                          SBUF = chksum;
              while (TI == 0)
                         {
                         }
                 TI = 0;
REN = 1;

}

        void displaytemp1(void)
{

                                check_sum =(0xA0 ^ 0xE2 ^ 0x07 ^ 0x00 ^ 0x62 ^ 0x00);

                                check_sum_tx = (check_sum & 0x7F);

                                InitByte_Char(0xA0);
                                InitByte_Char(0xE2);

                                InitByte_Char(0x07);
                                InitByte_Char(0x00);

                                sendremaining();
                                //InitByte_Char(0x62);
                        //      InitByte_Char(0x00);


                           // print2uart_hex(check_sum_tx);


}

void sendremaining(void)
{
InitByte_Char(0x62);
InitByte_Char(0x00);

print2uart_hex(check_sum_tx);

}


void displaycal(void)
{

                                check_sum =(0xA0 ^ 0xE2 ^ 0x07 ^ 0x00 ^ 0x25 ^ 0x00);

                                check_sum_tx = (check_sum & 0x7F);

                                InitByte_Char(0xA0);
                                InitByte_Char(0xE2);

                                InitByte_Char(0x07);
                                InitByte_Char(0x00);


                                InitByte_Char(0x25);
                        InitByte_Char(0x00);


                           print2uart_hex(check_sum_tx);

}

This is my code.
Over here I am trying to read bytes into SBUF and depending upon bytes received I am trying to send some packets.
My code is working but reading into SBUF is taking time...
Reading a single byte is not taking time but reading an entire packet takes time
can u suggest some alternative soln
regards
Mayuri

Parents
  • 0 in reply to Mayuri Ghosalkar

    I am helping you. I am saying that the ISR gets notified if there exists one (1) received byte. So the ISR should only try to pick up one (1) character.

    It's irrelevant what the protocol looks like - let the main loop worry about what characters are received - and when.

    Next thing - haven't you realized that you can receive one random character (maybe after insert of cable) and then get your 0xCC as second character. But your code think it should look at first entry of array for 0xCC. If you get a spurious character before the 0xCC, you get into a deadlock until the other side for some reason sends enough characters to get you out of your 5-character loop.

Reply
  • 0 in reply to Mayuri Ghosalkar

    I am helping you. I am saying that the ISR gets notified if there exists one (1) received byte. So the ISR should only try to pick up one (1) character.

    It's irrelevant what the protocol looks like - let the main loop worry about what characters are received - and when.

    Next thing - haven't you realized that you can receive one random character (maybe after insert of cable) and then get your 0xCC as second character. But your code think it should look at first entry of array for 0xCC. If you get a spurious character before the 0xCC, you get into a deadlock until the other side for some reason sends enough characters to get you out of your 5-character loop.

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