Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

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

3.7.2. System Integration of the Arm* DynamIQ Shared Unit

A DynamIQ cluster system comprises of two top-level modules:
  • A module which includes the core and the DSU
  • The DebugBlock
Separating the debug components from the cluster allows the debug components to be implemented in a separate power domain, allowing debug over power down.
The main components of the DSU are:
  • CPU bridges
  • Snoop control unit (SCU)
  • Clock and power management
  • L3 memory system
  • DSU system control registers
  • Debug and trace
Figure 9. DynamIQ Cluster Block Diagram
Table 54.  Main Components of the DSU
Component Description
CPU bridges The CPU bridges control buffering and synchronization between the cores and DSU.
Snoop Control Unit (SCU) The SCU maintains coherency between all the data caches in the cluster. The SCU contains buffers that can handle direct cache-to-cache transfers between cores without having to read or write data to the L3 cache. Cache line migration enables dirty cache lines to be moved between cores.
Clock and power management The cluster supports a set of power saving modes that are controlled by an external power controller.
L3 memory system

Main memory requester - The main memory interface supports 256-bit AMBA 5 CHI requester interface.

Peripheral port - The peripheral port is an optional manager interface and provides device access to tightly coupled accelerators. The port implements a 64-bit AXI 4 manager interface protocol. The peripheral port can be used for low-latency access to peripherals local to the cluster. It has the same latency as the main requester port. However, the overall system latency to devices that are connected to the main requester port is greater because of the higher latency of the system interconnect

L3 cache is implemented as 2MB.

DSU system control registers

The DSU implements a set of system control registers that provide:

  • Control for power management of the cluster
  • L3 cache partitioning control
  • CHI QoS bus control and scheme ID assignment
  • Information about the hardware configuration of the DSU
  • L3 cache hit and miss count information
Debug and trace Each core includes an Embedded Trace Macrocell (ETM) to allow program tracing while debugging. Trigger events from the cores are combined and output to the Debug APB requester. Trigger events to the cores, and debug register accesses, are received on the Debug APB completer.