Intel® Quartus® Prime Standard Edition User Guide: Timing Analyzer

ID 683068
Date 2/21/2024
Public
Document Table of Contents

2.3.7.5.2. End Multicycle Setup = 2 and End Multicycle Hold = 0

In this example, the end multicycle setup assignment value is two, and the end multicycle hold assignment value is zero.

Multicycle Constraint

set_multicycle_path -from [get_clocks clk_src] -to [get_clocks clk_dst] \
    -setup -end 2
Note:

The Timing Analyzer does not require an end multicycle hold value because the default end multicycle hold value is zero.

In this example, the setup relationship relaxes by a full clock period by moving the latch edge to the next latch edge. The hold analysis is does not change from the default settings.

The following shows the setup timing diagram for the analysis that the Timing Analyzer performs. The latch edge is a clock cycle later than in the default single-cycle analysis.

Figure 67. Setup Timing Diagram
Figure 68. Setup Check Calculation

The most restrictive setup relationship with an end multicycle setup assignment of two is 20 ns.

The following shows the setup report in the Timing Analyzer and highlights the launch and latch edges.

Figure 69. Setup Report

Because the multicycle hold latch and launch edges are the same as the results of hold analysis with the default settings, the multicycle hold analysis in this example is equivalent to the single-cycle hold analysis. The hold checks are relative to the setup check. Normally, the Timing Analyzer performs hold checks on every possible setup check, not only on the most restrictive setup check edges.

Figure 70. Hold Timing Diagram
Figure 71. Hold Check Calculation

This is the most restrictive hold relationship with an end multicycle setup assignment value of two and an end multicycle hold assignment value of zero is 10 ns.

Figure 72. Hold Report