Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 7/19/2024
Public
Document Table of Contents

5.1.6.1.4. Gate Control List Memory

The gate control list (GCL) memory is an external SPRAM and is used to store the gate control list. The GCL is the list in the controller memory that holds the gate controls and the associated time intervals in the 802.1Qbv Enhancements to Scheduled Traffic (EST) function.

The GCL memory depth is 256 and the memory is internally stored per the data width, which is 4 bytes (32 bits). The 512 x 4 B memory is physically stored as 2048 Bytes x 1 B (2 KB) memory which results in 9 bits of address width.
Note:
  • XGMAC’s internal operation with GCL requires a shadow memory allocation of the same size, hence the GCL memory depth must be doubled from 256 to 512.
  • The memory width is 24 which is the sum of the width of the time interval (ns) for the validity of a schedule. The number of traffic class is 8.

GCL memory is synchronous to the PTP clock (clk_ptp_ref_i).