Cortex-M4F FPU Hard Fault During Float Literal Multiplication The Cortex-M4F processor, equipped with a Floating Point Unit (FPU), is designed to accelerate floating-point computations, making it ideal for applications requiring high-performance mathematical operations. However, a common issue arises when attempting to multiply a float variable by a float literal, resulting in a system crash. This…
ARM Cortex-M Timers and the Prevalence of Down-Counters In ARM Cortex-M microcontrollers, timers are a critical component for real-time operations, task scheduling, and peripheral control. A notable design choice in these systems is the use of down-counters rather than up-counters. This preference is rooted in both software efficiency and hardware optimization. Down-counters, which decrement from…
Core 1 Fails to Execute from QSPI Flash with Incorrect Program Counter Jump When attempting to run bare-metal code on both cores of an ARM Cortex-A9 dual-core processor within an Intel Cyclone V SoC, Core 0 executes successfully from QSPI flash, while Core 1 fails to start correctly. Instead of jumping to its designated entry…
ARM Cortex-A53 Exception Handling and Mode Switching Fundamentals The ARM Cortex-A53 processor, part of the ARMv8-A architecture, supports multiple exception levels (ELs) and execution states (aarch32 and aarch64). Exception levels provide a hierarchical privilege model, with EL3 being the highest privilege level typically used for secure monitor code, EL2 for hypervisor functionality, and EL1 for…
Core 1 Program Counter Misdirection to 0xFEBAF5E8 The issue at hand involves the failure of Core 1 to execute its designated code when booting from QSPI flash on an Intel Cyclone V SoC with an ARM Cortex-A9 dual-core processor. While Core 0 operates as expected, Core 1’s program counter (PC) incorrectly jumps to the address…
ARM Cortex-M4 FPU Usage Verification Challenges When working with ARM Cortex-M4 processors that include a Floating-Point Unit (FPU), ensuring that all floating-point computations are performed using the hardware FPU rather than software libraries is critical for performance optimization. The Cortex-M4 FPU supports single-precision floating-point operations, and leveraging this hardware capability can significantly enhance the efficiency…
ARM Cortex-M4 Post-Silicon Compliance Testing Challenges Post-silicon compliance testing for ARM Cortex-M4 processors is a critical phase in the development lifecycle of embedded systems. This phase ensures that the silicon implementation of the Cortex-M4 core adheres to the architectural specifications and performs as expected under real-world conditions. The Cortex-M4, being a highly optimized processor for…
ARMv9 NEON Instruction Cycle Timing Documentation Gaps The ARMv9 architecture represents a significant evolution in ARM’s processor designs, introducing advanced features such as Scalable Vector Extension 2 (SVE2) and enhanced security capabilities. However, one area where developers face challenges is obtaining detailed cycle timing information for NEON instructions in ARMv9 processors. NEON, ARM’s advanced SIMD…
Cortex-M7 DWT Watchpoint Configuration and Debug Event Issues The Cortex-M7 processor’s Data Watchpoint and Trace (DWT) unit is a powerful tool for debugging complex issues such as race conditions, memory corruption, and unexpected behavior in embedded systems. The DWT allows developers to set watchpoints on specific memory addresses, triggering debug events when those addresses are…
ARM DSU Performance Evaluation Challenges and Goals The DynamIQ Shared Unit (DSU) is a critical component in modern ARM-based systems, responsible for managing shared resources such as L2 and L3 caches, power management, and core coordination in multi-core ARM Cortex-A and Cortex-R processors. Evaluating the performance of the DSU is essential for system architects and…