Creating Clock - 2020.2 English

Power Design Manager User Guide (UG1556)

Document ID
UG1556
Release Date
2021-11-19
Version
2020.2 English

When starting a manual estimation flow, it is recommended to create and generate the required clocks for the design. This will enable the clocks to be selected from the other resources tabs.

This clock creation can be performed using the Clock tab under the Estimation section.

Figure 1. Estimation Section

Fill in the details on the Clock tab to create a clock. Select if it is an external (coming from an I/O pin) or internal, from another block, such as the processing subsystem (PS) or a GT recovered clock for example.

Figure 2. Clock Tab

The fanout field for that clock will get populated automatically based on how many registers, block RAM, URAMs, and other resources are connected to that clock on their respective tabs.

Power Tip: Using this approach for the clock entry, PDM can more accurately estimate the clock power as the clock fanout is updated every time a clock is used in a Resources tab.

If power estimation is required for an MMCM or PLL, these can be specified in the Clock Managers table on the Clock tab.

Figure 3. Clock Managers

The reference clock is selected from one of the user-entered clocks in the Clock table. The multiply (M) and divide (D) can be specified as well as the output dividers. When this is entered, the output clock becomes available in the Clock table and is selectable on the other resource tabs such as Logic, DSP, URAM, block RAM, and I/O tabs to estimate the power of these blocks and the power of the clock network.