When my design contains a combinational feedback loop, a message similar to the following occurs:
This warning message reminds you to check for glitches or hazards. Hazard reduction circuitry is redundant in logic optimization.
To prevent the CPLD Fitter from optimizing this redundant logic away, add a NOREDUCE attribute to the equation to instruct the CPLD Fitter to not optimize this equation.
For more details on applying the NOREDUCE attribute, see the "Constraints Guide", which can be accessed at: