
MVME5100 VPD Reference Information
MVME5100 Single Board Computer Programmer’s Reference (6806800H17B
)
306
* 0xXX = checksum
*/
UCHAR
cssect(nvram_ptr, count)
register UCHAR *nvram_ptr; /* NVRAM buffer pointer */
register UINT count; /* count, number of bytes */
{
register UCHAR y, isum, sum;
for (sum = 0; count; count--) {
y = *nv+;
isum = sum + y;
if ((isum < y) || (isum < sum)) isum += 1;
sum = isum;
}
return (sum); /* return calculated checksum */
}
A.1.11.3 Serial Presence Detect (SPD) Checksum Calculation
The checksum field (Byte 63) designates the checksum for checking data integrity (similar to
parity) for bytes 0-62. It is written during board production and can be used to verify the data
integrity for these bytes.
Calculating the Checksum
To calculate the checksum, perform the following:
1.
Convert the binary information in byte locations 0-62 to decimal.
2. Add together (sum) all decimal values for addresses 0-62.
3. Divide the sum by 256.
4.
Convert the remainder to binary (will be less than 256).
Summary of Contents for MVME5100
Page 1: ...MVME5100 Single Board Computer Programmer s Reference P N 6806800H17B July 2014...
Page 8: ...MVME5100 Single Board Computer Programmer s Reference 6806800H17B Contents 8 Contents Contents...
Page 16: ...MVME5100 Single Board Computer Programmer s Reference 6806800H17B 16 List of Figures...
Page 292: ...Hawk Programming Details MVME5100 Single Board Computer Programmer s Reference 6806800H17B 292...
Page 312: ...VMEbus Mapping Example MVME5100 Single Board Computer Programmer s Reference 6806800H17B 312...
Page 316: ...Related Documentation MVME5100 Single Board Computer Programmer s Reference 6806800H17B 316...
Page 317: ......