MC9S08PA4 SCI debugging problems

[annyli]

when I debugging the MC9S08PA4 SCI, I can not write the SCI0_D registers when I want to send message. My configer is as following:

void Init_SCI0(void)
{
SYS_SOPT1_SCI0PS=1; //SCI0 RXD & TXD MAPPED ON PTA2 & PTA3
ADC_APCTL1_ADPC2=1; //disable the ADP
ADC_APCTL1_ADPC3=1; //disable the ADP

SCI0_BDH=0b00000000;//set the baud rate
SCI0_BDL=0b00110100; //baud rate is 9600 b/s, internal clock 8MHz
SCI0_C1=0x00;//0x00:8bits

SCI0_C2_TE=1; //TRANSMITTER ENABLE
SCI0_C2_TIE=1;//inable the interrupt
dummy=SCI0_S1;
  SCI0_D='a'; 
}

Who can help me? Pls...

[bigmac · Accepted solution]

Hello,

Since you have enabled transmit interrupts, you will need an interrupt handler.  If you do not have one, the MCU will most likely hang, eventually resulting in a COP timeout (unless the COP has been disabled).  Perhaps you do not need to use transmit interrupts.

void SCI_sendchar( byte c)

{

  while ((SCI0_S1 & 0x80) == 0);  // Wait for TDRE flag set

  SCI0_D = c;

}

Regards,

Mac

[annyli]

Hello,

Thank you for your help. But now I have the new problems, when I use interrupt to receive a data, the problem can't enter into the ISR.

I have enabled the SCI0_RIE=1; Following is the details:

Receiver Interrupt Enable for RDRF

0 Hardware interrupts from RDRF disabled; use polling.

1 Hardware interrupt requested when RDRF flag is 1.

And after send the data the RDRF flag has changed to 1, but the ISR did not run. The ISR code is as following:

void main(void) {

DisableInterrupts; /* enable interrupts */

MCU_init(); /* call Device Initialization */

Init_SCI0(); /* call Device Initialization */

EnableInterrupts;

while(!(SCI0_S1&0X80));

SCI0_D=0b00000011; //send the data

if (rx==0x03)

flag=1;

else

flag=0;

}

__interrupt void isrVsci0rx(void)

{

dummy=SCI0_S1; // 清除s1标志位第一步

rx=SCI0_D;

//EnableInterrupts;

}

__interrupt void isrVsci0rx(void)

{

dummy=SCI0_S1; // 清除s1标志位第一步

rx=SCI0_D;

//EnableInterrupts;

}

static void (* near const _vect[])(void) @0xFFB0 = { /* Interrupt vector table */

/*lint -restore Enable MISRA rule (1.1) checking. */

UNASSIGNED_ISR, /* Int.no. 39 Vnvm (at FFB0) Unassigned */

UNASSIGNED_ISR, /* Int.no. 38 VReserved38 (at FFB2) Unassigned */

UNASSIGNED_ISR, /* Int.no. 37 Vkbi0 (at FFB4) Unassigned */

UNASSIGNED_ISR, /* Int.no. 36 VReserved36 (at FFB6) Unassigned */

UNASSIGNED_ISR, /* Int.no. 35 Vrtc (at FFB8) Unassigned */

UNASSIGNED_ISR, /* Int.no. 34 VReserved34 (at FFBA) Unassigned */

UNASSIGNED_ISR, /* Int.no. 33 VReserved33 (at FFBC) Unassigned */

UNASSIGNED_ISR, /* Int.no. 32 VReserved32 (at FFBE) Unassigned */

UNASSIGNED_ISR, /* Int.no. 31 VReserved31 (at FFC0) Unassigned */

UNASSIGNED_ISR, /* Int.no. 30 VReserved30 (at FFC2) Unassigned */

UNASSIGNED_ISR, /* Int.no. 29 VReserved29 (at FFC4) Unassigned */

UNASSIGNED_ISR, /* Int.no. 28 VReserved28 (at FFC6) Unassigned */

UNASSIGNED_ISR, /* Int.no. 27 VReserved27 (at FFC8) Unassigned */

UNASSIGNED_ISR, /* Int.no. 26 VReserved26 (at FFCA) Unassigned */

isrVsci0tx, /* Int.no. 25 Vsci0tx (at FFCC) Used */

isrVsci0rx, /* Int.no. 24 Vsci0rx (at FFCE) Used */

isrVsci0err, /* Int.no. 23 Vsci0err (at FFD0) Used */

UNASSIGNED_ISR, /* Int.no. 22 Vadc (at FFD2) Unassigned */

UNASSIGNED_ISR, /* Int.no. 21 Vacmp (at FFD4) Unassigned */

UNASSIGNED_ISR, /* Int.no. 20 VReserved20 (at FFD6) Unassigned */

UNASSIGNED_ISR, /* Int.no. 19 VReserved19 (at FFD8) Unassigned */

UNASSIGNED_ISR, /* Int.no. 18 Vftm0ovf (at FFDA) Unassigned */

UNASSIGNED_ISR, /* Int.no. 17 Vftm0ch1 (at FFDC) Unassigned */

UNASSIGNED_ISR, /* Int.no. 16 Vftm0ch0 (at FFDE) Unassigned */

UNASSIGNED_ISR, /* Int.no. 15 Vftm1ovf (at FFE0) Unassigned */

UNASSIGNED_ISR, /* Int.no. 14 Vftm1ch1 (at FFE2) Unassigned */

UNASSIGNED_ISR, /* Int.no. 13 Vftm1ch0 (at FFE4) Unassigned */

UNASSIGNED_ISR, /* Int.no. 12 VReserved12 (at FFE6) Unassigned */

UNASSIGNED_ISR, /* Int.no. 11 VReserved11 (at FFE8) Unassigned */

UNASSIGNED_ISR, /* Int.no. 10 VReserved10 (at FFEA) Unassigned */

UNASSIGNED_ISR, /* Int.no. 9 VReserved9 (at FFEC) Unassigned */

UNASSIGNED_ISR, /* Int.no. 8 VReserved8 (at FFEE) Unassigned */

UNASSIGNED_ISR, /* Int.no. 7 VReserved7 (at FFF0) Unassigned */

UNASSIGNED_ISR, /* Int.no. 6 VReserved6 (at FFF2) Unassigned */

UNASSIGNED_ISR, /* Int.no. 5 VReserved5 (at FFF4) Unassigned */

UNASSIGNED_ISR, /* Int.no. 4 Vclk (at FFF6) Unassigned */

UNASSIGNED_ISR, /* Int.no. 3 Vlvw (at FFF8) Unassigned */

UNASSIGNED_ISR, /* Int.no. 2 Virq_wdog (at FFFA) Unassigned */

UNASSIGNED_ISR, /* Int.no. 1 Vswi (at FFFC) Unassigned */

_Startup /* Int.no. 0 Vreset (at FFFE) Reset vector */

};

在 2013-05-22 03:58:22，bigmac <admin@community.freescale.com> 写道：

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MC9S08PA4 SCI debugging problems

created by bigmac in 8-bit Microcontrollers - View the full discussion

Hello,

Since you have enabled transmit interrupts, you will need an interrupt handler. If you do not have one, the MCU will most likely hang, eventually resulting in a COP timeout (unless the COP has been disabled). Perhaps you do not need to use transmit interrupts.

void SCI_sendchar( byte c)

{

while ((SCI0_S1 & 0x80) == 0); // Wait for TDRE flag set

SCI0_D = c;

}

Regards,

Mac

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[bigmac]

Hello,

The primary problem with your test project is that the main() function does not enter a continuous loop following initialisation, but exits the function.  For a MCU, the main() function must never exit.  There may also be secondary issues regarding the handling of the COP (watchdog) timer to prevent COP reset.  I might suggest that you use the project wizard to create a main() framework for each new project, where both these issues are taken into account.

The following code demonstrates an alternative basic test project, where every character received by the SCI is immediately re-transmitted (echoed) back to the remote end.  I have not shown the code for the initialisation functions.  Additionally, I have defined the interrupt handler function using a "vector number", rather than including a vector table.

// Global variables:

byte rx;
byte flag = 0;

//*****************************************************************************
// Function prototypes:

void MCU_init( void);
void Init_SCI0( void);
void echo_char( void);
void SCI_sendchar( byte c);

//*****************************************************************************

void main(void)
{
  MCU_init();
  Init_SCI0();
  EnableInterrupts;

  for ( ; ; ) {      // Commence main loop
    __RESET_WATCHDOG();

    echo_char();     // Echo received character (if any)

  } // Loop always - do not exit main()
}

//*****************************************************************************
// Echo received character

void echo_char( void)
{
  if (flag) {       // New character received
    flag = 0;
    sendchar( rx);  // Send character
  }
}

//*****************************************************************************
// Send character to SCI0

void SCI_sendchar( byte c)
{
  while ((SCI0_S1 & 0x80) == 0);  // Wait for TDRE flag set
  SCI0_D = c;
}

//*****************************************************************************
// SCI0 Receive interrupt handler

__interrupt Vsci0rx
void isr_sci0rx(void)
{
  rx = SCI0_S1; // Part of clear flag process
  rx = SCI0_D;  // Fetch received character
  flag = 1;     // Flag new character available
}

Regards,

Mac

[annyli]

Dear Mac,

Thank you for all your help about the MC9S08PA4. Now we have another problem about I.MX 281. We write the bareboard program and want to dowload it into the SPI flash and boot from it. The problem is if we want to run our bareboard program in the SPI flash, what we need to do ?

Thank you very much for all your help.

Best Regards,

Tel: 0510-8029 5234

Anny Li

在 2013-05-30 21:37:21，bigmac <admin@community.freescale.com> 写道：

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MC9S08PA4 SCI debugging problems

created by bigmac in 8-bit Microcontrollers - View the full discussion

Hello,

The primary problem with your test project is that the main() function does not enter a continuous loop following initialisation, but exits the function. For a MCU, the main() function must never exit. There may also be secondary issues regarding the handling of the COP (watchdog) timer to prevent COP reset. I might suggest that you use the project wizard to create a main() framework for each new project, where both these issues are taken into account.

The following code demonstrates an alternative basic test project, where every character received by the SCI is immediately re-transmitted (echoed) back to the remote end. I have not shown the code for the initialisation functions. Additionally, I have defined the interrupt handler function using a "vector number", rather than including a vector table.

// Global variables:

byte rx;

byte flag = 0;

//*****************************************************************************

// Function prototypes:

void MCU_init( void);

void Init_SCI0( void);

void echo_char( void);

void SCI_sendchar( byte c);

//*****************************************************************************

void main(void)

{

MCU_init();

Init_SCI0();

EnableInterrupts;

for ( ; ; ) { // Commence main loop

__RESET_WATCHDOG();

echo_char(); // Echo received character (if any)

} // Loop always - do not exit main()

}

//*****************************************************************************

// Echo received character

void echo_char( void)

{

if (flag) { // New character received

flag = 0;

sendchar( rx); // Send character

}

}

//*****************************************************************************

// Send character to SCI0

void SCI_sendchar( byte c)

{

while ((SCI0_S1 & 0x80) == 0); // Wait for TDRE flag set

SCI0_D = c;

}

//*****************************************************************************

// SCI0 Receive interrupt handler

__interrupt Vsci0rx

void isr_sci0rx(void)

{

rx = SCI0_S1; // Part of clear flag process

rx = SCI0_D; // Fetch received character

flag = 1; // Flag new character available

}

Regards,

Mac

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[bigmac]

Hello Anny,

anny li wrote:

Thank you for all your help about the MC9S08PA4. Now we have another problem about I.MX 281. We write the bareboard program and want to dowload it into the SPI flash and boot from it. The problem is if we want to run our bareboard program in the SPI flash, what we need to do ?

Unfortunately, I am not familar with the iMX product.  You may do better to post this question to the iMX forum, if you have not already done so.

Regards,

Mac

[annyli]

Mac,

Thank you very much for all your help.