Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public
Document Table of Contents

3.7.3.4.1. DebugBlock

A DebugBlock is provided in the DSU that integrates an embedded cross trigger (ECT) with debugging registers and supports debug over powerdown. The DebugBlock is provided as a separate component to allow implementation in a separate power domain from the cluster. Having a separate debug power domain allows the connection to a debugger to be maintained while the cores and clusters are powered down.

The following diagram shows how the DebugBlock is connected to the cluster.
Figure 13. Debug APB Connections
The DebugBlock has three APB interfaces:
  • External Debug APB (DAP APB):
    • An APB completer interface allowing communication with an external debugger, for example, through a CoreSight Debug Access Port (DAP).
  • DebugBlock to cluster (DC APB):
    • An APB requester interface that is connected to the cluster. It sends all debug register read and write requests to the cluster.
  • Cluster to DebugBlock (CD APB):
    • An APB completer interface that is connected to the cluster. It receives CTI input trigger event requests from the cluster.
The main components of the DebugBlock are:
  • ECT
  • APB ROM
  • Event monitor
  • Event triggers
  • APB arbiter
  • DAP completer
Figure 14. DebugBlock Block Diagram
Table 56.  Main Components of the DebugBlock
Component Description
ECT The DebugBlock implements the embedded cross trigger (ECT). A cross trigger interface (CTI) is allocated to each PE in the cluster. The CTIs are interconnected through the cross trigger matrix (CTM).
APB ROM The APB ROM table holds the address decoding for each debug component in the DebugBlock and the cluster.
Event monitor The event monitor converts changes in CTI output triggers to APB write transactions.
Event triggers The event triggers convert APB write transactions to CTI input triggers.
APB arbiter The DC APB transfers both register accesses and CTI output trigger events. The APB arbiter multiplexes the two sources of transactions.
DAP completer The DAP completer holds copies of registers in the debug power domain.