Quartus® Prime Pro Edition User Guide: Design Optimization

ID 683641
Date 4/01/2024
Public

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5.1. Optimize Multi Corner Timing

Process variations and changes in operating conditions can result in path delays that are significantly smaller than those in the slow corner timing model. As a consequence, the design can present hold time violations on those paths, and in rare cases, additional setup time violations.

In addition, designs targeting newer device families (with smaller process geometry) do not always present the slowest circuit performance at the highest operating temperature. The temperature at which the circuit is slowest depends on the selected device, the design, and the compilation results. The Quartus® Prime software manages this new dependency by providing newer device families with three different timing corners—Slow 85°C corner, Slow 0°C corner, and Fast 0°C corner. For other device families, two timing corners are available—Fast 0°C and Slow 85°C corner.

The Optimize multi-corner timing option directs the Fitter to meet timing requirements at all process corners and operating conditions. The resulting design implementation is more robust across process, temperature, and voltage variations. This option is on by default, and increases compilation time by approximately 10%.

When this option is off, the Fitter optimizes designs considering only slow-corner delays from the slow-corner timing model (slowest manufactured device for a given speed grade, operating in low-voltage conditions).