AR# 53393

iMPACT - Checksum read from SPI Flash does not match value in the .prm file

Description

When I read the checksum in iMPACT from an SPI Flash, it does not match the value listed in the .prm file.

Why is this?

Solution

iMPACT uses a different algorithm for SPI Checksum calculation.

iMPACT will byte swap data before carrying out the byte addition.

PROM Generator does not do this.

iMPACT will consistently read the checksum, so a "Golden" version of the Checksum from a known good programming attempt can be used to compare iMPACT programming attempts.

Where programming is carried out by a non-Xilinx tool, the Checksum generated by the PROM Generator in the .prm file will be a better fit for comparison.

See (Xilinx Answer 18884) for details on how PROM Generator calculates a checksum and considerations when matching this checksum to one read from a device.

This issues is resolved in the Vivado Device Programmer 2014.3/2014.4.

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
47890 14.x iMPACT - Known Issues for the iMPACT 14.x tools N/A N/A
AR# 53393
Date 03/30/2015
Status Active
Type General Article
Devices
Tools More Less