Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public

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15.3.2.1. System Trace Macrocell

The STM-500 is a trace source that is integrated into a CoreSight* system, and is designed primarily for high-bandwidth trace of instrumentation embedded into software. Instrumentation trace is an easy way to output printf-style debugging. STM-500 trace have:

  • A dedicated AXI subordinate interface for receiving the instrumentation information.
  • Multiple processors and processes can share and directly access the STM without being aware of each other, by being allocated different pages in the STM stimulus space. 128 managers, each supporting 65,536 stimulus ports. Each 4KB page of the STM stimulus space provides 16 channels.
  • The STM can optionally stall the AXI when its FIFO becomes full, ensuring that no data is lost because of overflow, without having to poll the FIFO status in software.
  • Timestamping can be requested for each write independently, based on the address written to. You can also optimize the bandwidth by requesting a timestamp for only one write transaction in a message made up of several writes.

In addition to the AXI subordinate, the STM provides a hardware event tracing utilized for hardware validation by connecting signals of interest to the STM’s hardware event interface. The STM generates trace when signals are asserted on this interface.