External Memory Interface Handbook Volume 3: Reference Material: For UniPHY-based Device Families

ID 683841
Date 3/06/2023
Document Table of Contents

5.5.2. Clock Domains

The hard PHY contains circuitry that uses the following clock domains:

AFI clock domain (pll_afi_clk) —The main full-rate clock signal that synchronizes most of the circuit logic.

Avalon clock domain (pll_avl_clk) —Synchronizes data on the internal Avalon bus, namely the Read/Write Manager, PHY Manager, and Data Manager data. The data is then transferred to the AFI clock domain. To ensure reliable data transfer between clock domains, the Avalon clock period must be an integer multiple of the AFI clock period, and the phases of the two clocks must be aligned.

Address and Command clock domain (pll_addr_cmd_clk) —Synchronizes the global asychronous reset signal, used by the I/Os in this clock domain.