Restricted Fmax due to minimum period

Thank you for the question.

Regarding the first point — the maximum frequency specifications for other I/O standards (besides LVDS) — I don't believe there is a single table that explicitly lists them.

That said, while datasheets provide general electrical limits and guidance, the most accurate way to determine the maximum supported frequency for a specific I/O standard is to evaluate it directly in Quartus.

This is because Quartus incorporates key factors unique to your design, such as:

• Actual placement and routing
• I/O bank characteristics and configurations
• Drive strength, slew rate, and capacitive loading
• The realistic timing behavior of your chosen I/O standard in context

For example, TimeQuest Timing Analyzer in Quartus reports Fmax and I/O timing margins based on your real design constraints. This offers far more design-specific, accurate insight than static datasheet numbers.

Regarding Table 19: yes, for LVDS and LVPECL, a larger differential voltage swing can help support frequencies above 500 Mbps — but whether your implementation can actually achieve that depends on the routing quality, board-level signal integrity, and internal FPGA timing, all of which Quartus can evaluate directly.

So instead of relying solely on theoretical values, we highly recommend validating your desired frequency in Quartus. This gives you results that are:

• Specific to your implementation
• Validated by actual timing analysis
• Reliable for real-world use cases