SAS CRC check

[bassplyr647]

Forgive me if this has already been answered.  I am using the SASTest program from IGT and trying to verify the CRC.  I'm using the example code from the spec

Code: [Select]

unsigned short CRC (unsigned char *s, int len, unsigned short crcval)
{
   unsigned c,q;
   c = 0;
   q = 0;
 
   for(; len; len--)
   {
      c = *s++;
      q = (crcval ^ c) & 017;
      crcval = (crcval >> 4) ^ (q * 010201);
      q = (crcval ^ (c >> 4)) & 017;
      crcval = (crcval >> 4) ^ (q * 010201);
   }
   return (crcval);
}



 I am using this code on a 32-bit ARM processor.  Is the magic number different?  Does it matter?  Any advice/direction would be helpful.  FYI..I can read the full command, including the address-wakeup bit (this was verified using a logic analyzer).


Thanks in advance.

[iwalker]

Hi


My Arduino routine looks like this

Code: [Select]

void CalculateCRC(byte val[], int len)
{
  CRCH=0x00;
  CRCL=0x00;
 
  long crc;
  long q;
  byte c;
  crc = 0;
  for (int i = 0; i < len; i++)
  {
    c = val[i];
    q = (crc ^ c) & 0x0f;
    crc = (crc >> 4) ^ (q * 0x1081);
    q = (crc ^ (c >> 4)) & 0xf;
    crc = (crc >> 4) ^ (q * 0x1081);
  }
  CRCH =crc & 0xff;
  CRCL =crc >> 8;
}
 


Original Routine courtesy of Zarobhr on the old site - /nlg/index.php?topic=13799.0
Which Arm Micro / Dev environment are You working with ? As soon as I get a gap I want to try and migrate my project to the sparkCore.


Tx
Ian

[bassplyr647]

Thanks for the quick reply.  I found the problem...the seed value I was using was incorrect.  I'm using an NXP11xx (I'm testing with a NXP1115).  I'm going to be making my own boards. The "Host" system will be a Linux computer.