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AR# 124

FPGA Configuration - init goes Low, addresses keep incrementing (master parallel)


An XC4000 family device configured in master parallel mode appears to never finish configuration because the address lines

continue changing for long periods of time without the part ever configuring.


What is most likely occuring is that the INIT signal has gone Low, indicating that a configuration error has occurred. This means the checksum at the end of a data frame did not correlate with the data received. When this happens, the configuration of the device is halted, but the address lines will continue to toggle.

Causes for the INIT signal to go Low include: noise, swapped address/data bits, and the most common of all is the design has

been compiled for the wrong part type (and therefore, the frames are different sizes).

AR# 124
Date Created 08/21/2007
Last Updated 05/08/2014
Status Archive
Type General Article