|1||Use synchronous design practices. Pay attention to clock signals.|
In a synchronous design, a clock signal triggers all events. When all of the registers’ timing requirements are met, a synchronous design behaves in a predictable and reliable manner for all process, voltage, and temperature (PVT) conditions. You can easily target synchronous designs to different device families or speed grades.
Problems with asynchronous design techniques include reliance on propagation delays in a device, incomplete timing analysis, and possible glitches. Pay particular attention to your clock signals, because they have a large effect on your design’s timing accuracy, performance, and reliability. Problems with clock signals can cause functional and timing problems in your design. Use dedicated clock pins and clock routing for best results. For clock inversion, multiplication, and division, use the device PLLs. For clock multiplexing and gating, use the dedicated clock control block or PLL clock switchover feature instead of combinational logic. If you must use internally generated clock signals, register the output of any combinational logic used as a clock signal to reduce glitches. For example, if you divide a clock using combinational logic, clock the final stage with the clock signal that was used to clock the divider circuit.
For more information, refer to “PLL Board Design Guidelines”.
Cyclone® 10 GX devices do not support the Quartus Prime Design Assistant design-rule checking tool.
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