GIC Interrupt State Transitions and Linux Handling Flow The Generic Interrupt Controller (GIC) in ARM architectures plays a pivotal role in managing interrupts for multi-core systems. The GIC operates with a state machine that transitions interrupts through several states: Inactive, Pending, Active, and Active & Pending. Understanding these states is critical for diagnosing issues in…
ETM FIFOFULL Overload in High-Speed Cortex-M7 and M4 Systems The Embedded Trace Macrocell (ETM) is a critical component for real-time debugging and performance analysis in ARM Cortex-M processors. However, in high-speed systems such as those utilizing Cortex-M7 cores running at 1GHz or Cortex-M4 cores at 400MHz, the ETM can become overwhelmed, leading to FIFOFULL events….
Cortex-M7 vs. Cortex-M3 FIR Filter Performance Discrepancy Overview The performance discrepancy between the Cortex-M7 and Cortex-M3 processors when executing a 128-tap FIR filter implementation has raised significant questions. The Cortex-M7, clocked at 600 MHz, demonstrates a runtime of 1260 microseconds for the FIR filter, while the Cortex-M3, clocked at 84 MHz, takes 44028 microseconds. This…
Cortex-R52+ Interrupt Latency: Key Factors and Realistic Benchmarks Interrupt latency is a critical performance metric in real-time embedded systems, particularly when using high-performance processors like the ARM Cortex-R52+. The Cortex-R52+ is designed for safety-critical applications, such as automotive and industrial systems, where deterministic and low-latency interrupt handling is paramount. Understanding the typical interrupt latency figures…
Cortex-A53 STL Accessibility for Independent Developers The ARM Cortex-A53 Safety Test Library (STL) is a critical resource for developers working on safety-critical applications, particularly in industries such as automotive, industrial automation, and medical devices. The STL provides a suite of tests designed to validate the functional safety of Cortex-A53-based systems, ensuring compliance with industry standards…
Cacheable and Shareable Attributes in ARM Cortex-R5F: A Deep Dive The ARM Cortex-R5F processor, based on the ARMv7 architecture, is widely used in real-time embedded systems due to its deterministic performance and efficient memory management capabilities. One of the critical aspects of memory management in ARM processors is the configuration of memory attributes, specifically the…
GICv3 Interrupt Priority Change Challenges with Pending Interrupts The ARM Generic Interrupt Controller (GIC) version 3 (GICv3) is a sophisticated interrupt management system designed to handle a wide range of interrupt scenarios in modern ARM-based systems. One of the more nuanced challenges when working with GICv3 is dynamically changing the priority of an interrupt that…
ARM Cortex-M85 ETM Data Trace Unsupported: Understanding the Limitation The ARM Cortex-M85 processor, a high-performance embedded processor designed for AI and machine learning applications, integrates the Arm CoreSight ETM-M85 (Embedded Trace Macrocell) for instruction tracing. However, a critical limitation arises when attempting to perform data tracing. The ETM-M85, as documented in the "Arm CoreSight ETM-M85…
Cortex-R52 Memory Map Flexibility and Design Philosophy The Cortex-R52 processor, unlike its Cortex-M series counterparts, does not come with a predefined default memory map. This design choice is intentional and stems from the need to provide system designers with maximum flexibility when integrating the Cortex-R52 into System-on-Chip (SoC) designs. The Cortex-R52 is often used in…
ARM Cortex-A9 MMU Setup for Multi-Core Data Sharing and Cache Coherency When working with the ARM Cortex-A9 MPcore processor, particularly in a multi-core bare-metal environment, configuring the Memory Management Unit (MMU) correctly is critical to ensure proper data sharing, cache coherency, and overall system performance. The Cortex-A9 MMU provides a flexible mechanism to define memory…