Author: System on Chips

ARM Cortex-M Privilege Mode Challenges in Driver Implementation Running driver code in privileged mode on ARM Cortex-M processors is a common requirement for ensuring secure and reliable access to hardware peripherals. However, the transition between user mode and privileged mode introduces complexities, particularly when developers aim to abstract this process for ease of use. The…

Cortex-M MPU Privileged Code Access Violation Behavior When working with the Cortex-M Memory Protection Unit (MPU), one of the critical scenarios to understand is how the processor handles user-mode attempts to access privileged code regions. In this case, the privileged code is stored in a memory region configured as privileged-read-only, user-denied, and executable. When a…

ARMv8-A Architecture and SVE Instruction Set Compatibility in Qualcomm Centriq 2400 The Qualcomm Centriq 2400 is a server-grade processor based on the ARMv8-A architecture, which is widely used in high-performance computing and embedded systems. The Scalable Vector Extension (SVE) is an optional feature within the ARMv8-A architecture, designed to enhance vector processing capabilities for workloads…

Cortex-A53 MIPS Calculation and Its Limitations The Cortex-A53 is a highly efficient ARMv8-A processor core designed for low-power applications, often found in mobile devices and embedded systems. One of the key metrics used to evaluate processor performance is MIPS (Millions of Instructions Per Second), which provides a theoretical upper bound on the number of instructions…

ARMv8 PMU Cycle Counter Instability During Secure-EL1 Code Execution The Performance Monitoring Unit (PMU) in ARMv8 architectures is a critical tool for measuring the performance of code execution, particularly in low-level environments such as Secure-EL1. However, when attempting to measure the cycle count of a simple loop in Secure-EL1 on an ARMv8 big.LITTLE system, unstable…

ARM Cortex-M Thumb-2 Instruction Set and Function Pointer Misalignment The issue at hand involves a Hardfault error occurring during the execution of a callback function in an ARM Cortex-M-based system. The fault manifests when the program attempts to branch to a function pointer stored in register r3. The function pointer value in r3 is 0x00422091,…

ARM Cortex-M0+ Hard Fault During Interrupt Handling and EEPROM Access The issue at hand involves a hard fault occurring on an ARM Cortex-M0+ microcontroller (specifically the STM32L0x1 series) during an interrupt service routine (ISR) that attempts to copy data to EEPROM. The hard fault persists even when the EEPROM write operation is removed, suggesting a…

ARM Cortex-A9 Compilation Issues with Ne10 Library and ARM Compiler 5 The Ne10 library, a popular open-source library optimized for ARM architectures, is designed to leverage the capabilities of ARM processors, particularly for signal processing, matrix operations, and other computationally intensive tasks. However, integrating the Ne10 library into projects using ARM Compiler 5 (also known…

ARM Cortex-R5 and Cortex-A53 Architectural Differences and Compatibility Challenges The coexistence of ARM Cortex-R5 and Cortex-A53 cores in a single system presents several architectural and compatibility challenges. The Cortex-R5 is based on the ARMv7-R architecture, which is designed for real-time applications, while the Cortex-A53 is based on the ARMv8-A architecture, targeting general-purpose and mobile applications….

ARM Cortex-M0/M3 DesignStart Pro Licensing and GDSII File Access The ARM Cortex-M0 and Cortex-M3 processors are widely used in embedded systems due to their low power consumption, high performance, and ease of integration. For students and professionals looking to tape out a System-on-Chip (SoC) using these processors, understanding the licensing options and the availability of…