Good afternoon,
This has got me completely baffled. When I run my test code that reads and writes to the SDRAM looking for errors is gets thousands of errors in debug mode because it appears data bit 9 is always high. However when I run the same code from the flash it doesn't find any errors with the SDRAM.
I am using a C6713B DSP on a custom board and with a XDS510 USB emulator and CCS v5.1.0.09000
Can anybody offer a logical explanation to this and tel me what the problem might be? Here is my test code
while(0){
unsigned int temp = 0xFFFF;
unsigned int count = 0;
unsigned int error = 0;
unsigned int buffer;
int i = 0;
char buf [100];
ComPuts(" \r\nTesting SDRAM\r\n");
temp = 0xFFFF;
count = 0;
error = 0;
while (count < 0x10000)
{
*((unsigned short *)(0x80000000 | count)) = (unsigned short) temp;
count += 2;
temp -= 1;
if(temp == 0xFFFFFFFF)
temp = 0xFFFF;
}
count = 0;
temp = 0xFFFF;
while (count < 0x10000)
{
buffer = *((unsigned short *)(0x80000000 | count)) & 0xFFFF;
if(buffer != temp)
{
error++;
while(1)
{
// *((unsigned int *)(0x80000000 | count)) = temp - 2;
// buffer = *((unsigned int *)(0x80000000 | count)) & 0xFFFF;
// if((buffer + 2) == temp)
break;
}
}
else if (buffer == temp)
while(1)
break;
if (buffer != 0xFFFFFFFF)
while(1)
break;
else if (buffer == 0xFFFFFFFF)
while(1)
break;
count += 2;
temp -= 1;
if(temp == 0xFFFFFFFF)
temp = 0xFFFF;
}
sprintf(buf, "SDRAM errors %d\r\n", error);
ComPuts( buf );
if(error)
error = 0;
temp = 0x0FFFFFFF;
while(temp-- != 0);
}
Kind regards
Sean
