Configuration memory cells in an integrated circuit (IC) may be corrupted
by cosmic radiation and other sources, causing improper operation of the
IC. Reliability of an IC is improved by refreshing subsets, such as
frames, of the configuration data according to a schedule that has one
subset being refreshed more frequently than another subset. For each
subset of the configuration data, a respective indicator is determined
that indicates whether a subset of configuration memory of the IC
requires refreshing with the subset of configuration data. The indicator
may be a probability that corruption of the subset of configuration
memory results in improper operation. A schedule for refreshing the
subsets of configuration memory is generated from the indicators. The
subsets of configuration memory are refreshed according to the schedule,
with one subset being refreshed more frequently than another subset.