NSS-30012: Design Contains Latches
Description
Latches are structures where two sets of two-input combinational logic (which the compiler implements in logic cells) are cross-coupled using combinational loops. These combinational loops drive the output of one set of logic to an input of the other set of logic.
A latch can cause glitches and ambiguous timing in a design, which makes timing analysis of the design difficult. In addition, a latch can cause significant stability and reliability problems in a design. This is because the behavior of the combinational loops in the latch often depends on the relative propagation delays of the combinational loop's logic, causing the combinational loop to behave differently under different operation conditions.
Recommendation
Do not include latches in your design.
Severity
High
Stage
Analysis and Elaboration
Device Family
- Intel® Arria® 10
- Intel® Cyclone® 10 GX