Is the checksum provided by Altera® tools a good way to represent a unique signature of the programming data in an Altera device?

Description

No. Checksum is a simple sum of the number of programmed bits in the pattern. It is a concept that had moderate value for simple programmable logic devices (PLDs) with less than 16 logic cells. However, even with those smaller devices, the value was far from unique. As devices have gotten larger, this summing of the number of bits is of less value.

Altera does not recommend using checksums as a means of uniquely representing a pattern in a device. Altera recommends using a verify operation to confirm that a device has been programmed with the correct pattern.

The Joint Test Action Group (JTAG) IEEE 1149.1 specification also provides a better mechanism for providing a unique signature for the pattern, called the USERCODE instruction. APEX^TM 20K, APEX 20KE, ACEX^TM 1K, FLEX^® 10K, FLEX 10KA, FLEX 10KE, MAX^® 7000AE, MAX 7000B, MAX 3000A, and EPC devices support the optional USERCODE instruction.

Related Articles

• Why is the checksum value generated by the Quartus II software programmer different than the checksum value generated by the Tcl checksum command?