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Problems with Passing Pointers as Parameters

Chris Beattie

Okay, I'm trying to pass a pointer to a char buffer to a function. It works fine in the Keil simulator/debugger, but not on the target hardware.

// Variable Declaration
#define MAX_RX_SIZE 100
static char xdata cmdBuffer[MAX_RX_SIZE];

// Calling function
void CallingFunc(void) {
// cmdBuffer is read in from serial
// port and contains "EF"
printf("\r\nP2_CMDFOUND\r\n");
printf(cmdBuffer);

if (!process_EraseFlash(cmdBuffer)) {
printf("\r\nP2_INVALARG\r\n");
printf(cmdBuffer);
printf("\n**invalid arguments");
}
else {
printf("\r\nFcn Success\r\n");
printf(cmdBuffer);
}
}

// Called Function
BYTE process_EraseFlash(char *cmdBuffer) reentrant
{
printf("\r\nP2_CMDEF\r\n");
printf(cmdBuffer);
if (strcmp(cmdBuffer, "EF"))
return FALSE;

if (flash_ChipErase())
printf("\r\nOK");
else
printf("\r\n**Error>\r\n");
return TRUE;
}

Okay, here's the output from the simulator:
P2_CMDFOUND
EF
P2_CMDEF
EF
OK
Fcn Success
EF

And here's the output from the target hardware:
P2_CMDFOUND
EF
P2_CMDEF

P2_INVALARG
EF
**invalid arguments

Looks like the pointer is not being passed to the process function properly, as the process function thinks the buffer is empty.

Any ideas? I'm stuck here.

Thanks,
Chris Beattie

Parents
  • 0

    Okay, I'm trying to pass a pointer to a char buffer to a function. It works fine in the Keil simulator/debugger, but not on the target hardware.

    // Variable Declaration
#define MAX_RX_SIZE 100
static char xdata cmdBuffer[MAX_RX_SIZE];

// Calling function
void CallingFunc(void) {
  // cmdBuffer is read in from serial
  // port and contains "EF"
  printf("\r\nP2_CMDFOUND\r\n");
  printf(cmdBuffer);

  if (!process_EraseFlash(cmdBuffer)) {
    printf("\r\nP2_INVALARG\r\n");
    printf(cmdBuffer);
    printf("\n**invalid arguments");
  }
  else {
    printf("\r\nFcn Success\r\n");
    printf(cmdBuffer);
  }
}

// Called Function
BYTE process_EraseFlash(char *cmdBuffer) reentrant
{
  printf("\r\nP2_CMDEF\r\n");
  printf(cmdBuffer);
  if (strcmp(cmdBuffer, "EF"))
    return FALSE;

  if (flash_ChipErase()) 
    printf("\r\nOK");
  else 
    printf("\r\n**Error>\r\n");
  return TRUE;
}
    Okay, here's the output from the simulator:
    P2_CMDFOUND
EF
P2_CMDEF
EF
OK
Fcn Success
EF
    And here's the output from the target hardware:
    P2_CMDFOUND
EF
P2_CMDEF

P2_INVALARG
EF
**invalid arguments
    Looks like the pointer is not being passed to the process function properly, as the process function thinks the buffer is empty.

    Any ideas? I'm stuck here.

    Thanks,
    Chris Beattie

Reply
  • 0

    Okay, I'm trying to pass a pointer to a char buffer to a function. It works fine in the Keil simulator/debugger, but not on the target hardware.

    // Variable Declaration
#define MAX_RX_SIZE 100
static char xdata cmdBuffer[MAX_RX_SIZE];

// Calling function
void CallingFunc(void) {
  // cmdBuffer is read in from serial
  // port and contains "EF"
  printf("\r\nP2_CMDFOUND\r\n");
  printf(cmdBuffer);

  if (!process_EraseFlash(cmdBuffer)) {
    printf("\r\nP2_INVALARG\r\n");
    printf(cmdBuffer);
    printf("\n**invalid arguments");
  }
  else {
    printf("\r\nFcn Success\r\n");
    printf(cmdBuffer);
  }
}

// Called Function
BYTE process_EraseFlash(char *cmdBuffer) reentrant
{
  printf("\r\nP2_CMDEF\r\n");
  printf(cmdBuffer);
  if (strcmp(cmdBuffer, "EF"))
    return FALSE;

  if (flash_ChipErase()) 
    printf("\r\nOK");
  else 
    printf("\r\n**Error>\r\n");
  return TRUE;
}
    Okay, here's the output from the simulator:
    P2_CMDFOUND
EF
P2_CMDEF
EF
OK
Fcn Success
EF
    And here's the output from the target hardware:
    P2_CMDFOUND
EF
P2_CMDEF

P2_INVALARG
EF
**invalid arguments
    Looks like the pointer is not being passed to the process function properly, as the process function thinks the buffer is empty.

    Any ideas? I'm stuck here.

    Thanks,
    Chris Beattie

Children
  • 0 in reply to Chris Beattie

    Hi Erik,<br>
    <br>
    well, just looked it up again... you can sure use the internal clock too. I just remembered an old application of mine, where I used a variable external clock to meassure the length of something moving through a light barrier. The external clock was relative to the speed of the movement. So I was not sure, if the c51 would be able to use the internal clock for the capture mode... just too long ago :))<br>
    <br>
    Take care<br>
    Sven