8-bit Microcontrollers中的主题 Re: Overwritten memory; MC9S08AW60

Overwritten memory; MC9S08AW60

janr_ — Thu, 01 Aug 2013 09:09:10 GMT

Hello,

I try to tesst my programm with the True time simulator.

However after sbufferpos = 15 (after 15 times ISR_Interrupt) some parts of the buffer array will be overwritten.

Then there occurs an error:

Error: At location 0057 -

Error: Attempt to execute from unimplemented (--) ROM

Do you have any idea how to fix this problem?

// Includes ----------------------------------------------------------------------------------------

#include <hidef.h> /* for EnableInterrupts macro */

#include "derivative.h" /* include peripheral declarations */

#include "SPIDriver.h"

// Variablen ---------------------------------------------------------------------------------------

static volatile int sbufferpos = 0;

byte buffer[33];

// Prototypen --------------------------------------------------------------------------------------

void BefehlsbufferErstellen(int takt);

void SendeBuffer(byte b);

// Main --------------------------------------------------------------------------------------------

void main(void) {

spi_init();

spi_setMode(Master, FallingEdge, LeadingEdge, MSBfirst);

spi_selectChip(true,0);

BefehlsbufferErstellen(27);

spi_enableInterrupt(true);

for(;;)

{

__RESET_WATCHDOG();

}

// Interruptroutinen ---------------------------------------------------------------------------------

__interrupt VectorNumber_Vspi1 void ISR_SPI() {

if((SPI1S&(SPI1S_SPRF_MASK)) == 0) {

}

else{

SPI1S;

SPI1D;

}

if((SPI1S&(SPI1S_SPTEF_MASK)) == 0){

}

else{

spi_enableInterrupt(false);

if(sbufferpos > sizeof(buffer) - 1) {

sbufferpos = 0;

} else{

SendeBuffer(buffer[sbufferpos]);

sbufferpos++;

spi_enableInterrupt(true);

}

// Funktionen -----------------------------------------------------------------------------------------

void BefehlsbufferErstellen (int takt) {

if(takt== 27) {

buffer[0]= 0x9F; // Set Address

buffer[1]= 0x24; // 36d

buffer[2]= 0x40; // Write

buffer[3]= 0x4F; // 4Fh

buffer[4]= 0x9F; // Set Address

buffer[5]= 0x28; // 40d

buffer[6]= 0x40; // Write

buffer[7]= 0x00; // 00h

buffer[8]= 0x9F; // Set Address

buffer[9]= 0x29; // 41d

buffer[10]= 0x40; // Write

buffer[11]= 0x02; // 02h

buffer[12]= 0x9F; // Set Address

buffer[13]= 0x30; // 42d

buffer[14]= 0x40; // Write

buffer[15]= 0x9F; // 0x9Fh

buffer[16]= 0x9F; // Set Address

buffer[17]= 0x32; // 44d

buffer[18]= 0x40; // Write

buffer[19]= 0x00; // 00h

buffer[20]= 0x9F; // Set Address

buffer[21]= 0x33; // 45d

buffer[22]= 0x40; // Write

buffer[23]= 0x0D; // 0Dh

buffer[24]= 0x9F; // Set Address

buffer[25]= 0x35; // 47d

buffer[26]= 0x40; // Write

buffer[27]= 0x00; // 00h

buffer[28]= 0x9F; // Set Address

buffer[29]= 0x36; // 48d

buffer[30]= 0x40; // Write

buffer[31]= 0x0D; // 0Dh

}

else if(takt == 26){

buffer[0]= 0x9F; // Set Address

buffer[1]= 0x24; // 36d

buffer[2]= 0x40; // Write

buffer[3]= 0x3D; // 3Dh

buffer[4]= 0x9F; // Set Address

buffer[5]= 0x28; // 40d

buffer[6]= 0x40; // Write

buffer[7]= 0x20; // 20h

buffer[8]= 0x9F; // Set Address

buffer[9]= 0x29; // 41d

buffer[10]= 0x40; // Write

buffer[11]= 0x95; // 95h

buffer[12]= 0x9F; // Set Address

buffer[13]= 0x30; // 42d

buffer[14]= 0x40; // Write

buffer[15]= 0xFF; // FFh

buffer[16]= 0x9F; // Set Address

buffer[17]= 0x32; // 44d

buffer[18]= 0x40; // Write

buffer[19]= 0x03; // 03h

buffer[20]= 0x9F; // Set Address

buffer[21]= 0x33; // 45d

buffer[22]= 0x40; // Write

buffer[23]= 0xE8; // E8h

buffer[24]= 0x9F; // Set Address

buffer[25]= 0x35; // 47d

buffer[26]= 0x40; // Write

buffer[27]= 0x03; // 03h

buffer[28]= 0x9F; // Set Address

buffer[29]= 0x36; // 48d

buffer[30]= 0x40; // Write

buffer[31]= 0xE8; // E8h

}

else {

}

void SendeBuffer(byte b) {

__RESET_WATCHDOG();

spi_sendData(b);

}

Re: Overwritten memory; MC9S08AW60

weapon — Fri, 02 Aug 2013 08:26:49 GMT

I didn't see any problem in your code. could you provide the whole project to me? I'd like to check the PRM file and MAP file.

Best Regards

XWP

Re: Overwritten memory; MC9S08AW60

bigmac — Fri, 02 Aug 2013 14:25:00 GMT

Hello,

These symptoms would indicate a stack overflow problem. It may be possible that you have an unintended nested interrupt situation. The spi_enableInterrupt() function might be a possible cause, if it is globally enabling interrupts within the ISR function. The use of this function within the ISR would seem unnecessary, except for the final disable of the SPI interrupt when the data sequence is completed. I would also suspect that you have the SPTEF interrupt enabled, which will exacerbate the problem.

If you wish to use interrupts for SPI master operation, only the RDRF interrupt should be enabled - the SPTEF interrupt should remain disabled. When the RDRF flag becomes set, this means that the transfer of the last send byte has been completed, and the next byte may now be sent after the RDRF flag has been cleared. It is not necessary to test the SPTEF flag.

I assume that the spi_selectChip() function is simply enabling the CS signal to the external device. You do not appear to be disabling the signal after completion of the send sequence. Since the data sequence is loaded byte-by-byte into the array variable, this would seem very inefficient. An alternative method would be to create constant array variables directly within flash memory. The data can then be accessed using a pointer variable, without the need for using an array variable. The following code snippet shows this approach.

//-----------------------------------------------------------------------------
// Global variables:

volatile byte *pntr;
volatile byte buf_count;

//-----------------------------------------------------------------------------
// Data sequence tables:

const byte data_seq1[] = {
0x9F, 0x24, 0x40, 0x4F,
0x9F, 0x28, 0x40, 0x00,
0x9F, 0x29, 0x40, 0x02,
0x9F, 0x30, 0x40, 0x9F,
0x9F, 0x32, 0x40, 0x00,
0x9F, 0x33, 0x40, 0x0D,
0x9F, 0x35, 0x40, 0x00,
0x9F, 0x36, 0x40, 0x0D
};

const byte data_seq2[] = {
0x9F, 0x24, 0x40, 0x3D,
0x9F, 0x28, 0x40, 0x20,
0x9F, 0x29, 0x40, 0x95,
0x9F, 0x30, 0x40, 0xFF,
0x9F, 0x32, 0x40, 0x03,
0x9F, 0x33, 0x40, 0xE8,
0x9F, 0x35, 0x40, 0x03,
0x9F, 0x36, 0x40, 0xE8
};

//-----------------------------------------------------------------------------

void main(void)
{
SPI_init();
EnableInterrupts; // Globally enable interrupts

SPI_selectChip( true, 0);     // Enable SPI slave device
SPI_send_start( 27);          // Start send sequence
while (buf_count)             // Wait until send sequence completed
    __RESET_WATCHDOG();
SPI_selectChip( false, 0);    // Disable SPI slave device

for( ; ; ) {
    __RESET_WATCHDOG();

}
}

//-----------------------------------------------------------------------------
// Start SPI send sequence

void SPI_send_start( byte takt)
{
if (takt == 27) pntr = data_seq1;
if (takt == 26) pntr = data_seq2;
if (takt) {
    while (SPI1S_SPTEF == 0);
    SPI1D = *pntr++;            // Send first byte of sequence
    buf_count = 31;
    SPI_Interrupt( true);       // Enable SPRF interrupts
}
else buf_count = 0;
}

//-----------------------------------------------------------------------------
// Interrupt functions:

__interrupt VectorNumber_Vspi1
void ISR_SPI( void)
{
(void)SPI1S; // Clear SPRF flag
(void)SPI1D;

if (buf_count) {
    SPI1D = *pntr++;
    buf_count--;
}
else
    SPI_Interrupt( false);      // Disable SPI interrupts
}

Regards,

Mac