Architectures and Processors

ARM Cortex-A720 and DSU-120 Core Grouping for Virtualization and ASIL-B Compliance The ARM Cortex-A720, coupled with the DynamIQ Shared Unit (DSU-120), offers a highly configurable multi-core architecture that can be tailored for various use cases, including virtualization and safety-critical applications like ASIL-B compliance. A key question arises: can the cores be logically or physically partitioned…

TCM Memory MPU Configuration and Execute-Never (XN) Permissions Conflict The Cortex-R5 processor, a member of ARM’s real-time processor family, is widely used in embedded systems for its deterministic performance and low-latency response. One of its key features is the Tightly Coupled Memory (TCM), which provides fast, predictable access to critical code and data. However, configuring…

ARM Processor Identification Mechanisms in Multi-Core Architectures In multi-core ARM systems, identifying individual processors is a critical task for ensuring proper system initialization, task allocation, and runtime management. The ARM architecture provides several mechanisms for processor identification, each tailored to specific use cases and architectural variants. The primary registers involved in this process are the…

ARM Cortex-A53 Exception Level Transition Issues During BSP Development When developing a Board Support Package (BSP) for the NXP i.MX8M Mini, which utilizes the ARM Cortex-A53 processor, transitioning from Exception Level 3 (EL3) to Exception Level 1 (EL1) can be a complex task. The Cortex-A53 processor, being part of the ARMv8-A architecture, supports multiple exception…

ARM Cortex-A53 Cache Invalidation Blocking Issue During DC IVAC Operation The ARM Cortex-A53 processor, a widely used 64-bit ARMv8-A core, is known for its efficiency and performance in embedded systems. However, a specific issue has been observed when performing cache invalidation operations using the DC IVAC (Data Cache Invalidate by Virtual Address to PoC) instruction….

Understanding Cortex-R52 CoreMark and DMIPS Performance Metrics The ARM Cortex-R52 is a high-performance real-time processor designed for safety-critical applications, offering features like dual-core lockstep, error correction, and advanced fault tolerance. Its performance is often measured using industry-standard benchmarks such as CoreMark and DMIPS (Dhrystone MIPS). CoreMark is a modern benchmark that evaluates the efficiency of…

Cortex-R5 L1 Cache Write-Streaming Mode and Cache Miss Anomalies The ARM Cortex-R5 processor is widely used in real-time embedded systems due to its deterministic performance and robust feature set. One of the key features of the Cortex-R5 is its L1 cache subsystem, which includes separate instruction and data caches. However, there is some ambiguity regarding…

ARM Cortex-R5 Link Register Offsets in Exception Modes The ARM Cortex-R5 processor, like other ARM cores, handles exceptions by saving the return address in the Link Register (LR) of the respective exception mode. However, the value stored in the LR can vary depending on the processor mode (ARM or Thumb) and the type of exception….

Understanding the Cortex-X4 Transistor Count and Physical Implementation The Cortex-X4, as part of Arm’s high-performance CPU lineup, is designed to deliver exceptional performance for advanced computing tasks. However, determining the exact transistor count or physical size of the Cortex-X4 core is not straightforward due to the nature of Arm’s business model and the flexibility it…

Cortex-A15 Deadlock Due to Shared L2 Cache State in ACE Systems The Cortex-A15 processor, particularly in revision r2p4, is susceptible to a rare but critical deadlock condition when operating in an ACE (AXI Coherency Extensions) system. This deadlock arises under specific conditions involving shared L2 cache states, multiple caching masters, and the interplay between readUnique…