Category: I/O
Tool: Diamond
Device: MachXO2, MachXO3

Use the GPLL pin for clock input to the PLL. Dedicated wiring is used up to the CLKI port of the PLL, minimizing the delay time. Basically, it is possible to input the clock to the PLL from any input pin, but the input delay increases because it goes through the general wiring.

Use the PCLK pin for external clock input without PLL. Dedicated routing is used to get on the dedicated clock routing (Primary Clock), which minimizes the so-called injection delay time. Basically, any input pin can be assigned to the clock dedicated wiring, but the injection delay will increase because it goes through the general wiring in cases other than the PCLK pin.

When using differential signals such as LVDS, use the "T" (True = non-inverted) and "C" (Complementary = inverted) pair, but be sure to use the "T" side for single-ended signals. .
Also, for differential signals, there is no need to specify the inverting input in the RTL description. Similarly, it is not necessary to specify the reverse side for the pin arrangement. Specify only the non-inverted side for both the GPLL pin and PCLK pin. The tool will automatically take care of using the appropriate reverse side pin pairing.