AXI Slave Behavior with WR_STRB=0 and WVALID=1 The Advanced eXtensible Interface (AXI) protocol is a widely used on-chip communication standard for high-performance embedded systems. It defines a set of rules for data transfer between masters and slaves, ensuring efficient and reliable communication. One of the key signals in the AXI write data channel is WR_STRB…
ARM Cortex-M0+ Core Generality and Vendor-Specific Implementations The ARM Cortex-M0+ is a widely adopted 32-bit RISC processor core designed for embedded applications requiring low power consumption and high efficiency. While the Cortex-M0+ core itself is standardized by ARM, its implementation across different vendors introduces variability due to optional features, proprietary peripherals, and vendor-specific tooling. This…
ARM Cortex-M0+ Watchdog Timer Interrupt Handling Failure The issue at hand involves the Watchdog Timer (WDT) interrupt handler (WDT_IRQHandler) not being executed on an nRF51 microcontroller, which is based on the ARM Cortex-M0+ architecture. The user has configured the WDT to trigger an interrupt after a timeout period, but the interrupt handler is not being…
Identifying PMU Version and Features in ARM Cortex-A73 Processors The Performance Monitoring Unit (PMU) in ARMv8 architectures is a critical component for profiling and debugging system performance. However, determining the specific PMU version and features implemented in a particular ARM Cortex-A73 processor can be challenging due to the variability in ARMv8 implementations. The ARM Architecture…
VFMA Instruction Execution and Pipeline Behavior on ARM Cortex-M4 The ARM Cortex-M4 processor is a widely used microcontroller core that features a single-precision floating-point unit (FPU) and supports advanced SIMD instructions, including the Vector Fused Multiply-Accumulate (VFMA) instruction. The VFMA instruction is critical for high-performance signal processing, machine learning, and other compute-intensive tasks. However, understanding…
ARM Cortex-A53 NEON and FPU Optimization Challenges with GCC The ARM Cortex-A53 is a widely used 64-bit processor core that is part of the ARMv8-A architecture. It is commonly employed in embedded systems and applications requiring high efficiency and performance. One of the key features of the Cortex-A53 is its support for Advanced SIMD (NEON)…
BusFault Triggered by Invalid Pointer Dereference During System Initialization The core issue revolves around a BusFault occurring during system power-up, specifically when dereferencing a pointer (*pp_data) in the function uarte_get_async_data. The fault manifests as an access to an invalid memory address (0x0601235d), which is not a valid memory location for the system. This fault is…
ARM Cortex-M Linux Kernel Boot Failure in STM32MP157 The core issue revolves around attempting to run a Linux kernel on a Cortex-M microcontroller within the STM32MP157 evaluation board, specifically encountering a failure in the __free_pages_bootmem function during kernel initialization. This function is part of the Linux kernel’s memory management subsystem, responsible for freeing pages allocated…
ARM Cortex-M4 Cross-Compiler Memory Allocation Error During Large File Compilation When working with embedded systems, particularly those based on ARM Cortex-M4 processors, developers often rely on cross-compilers to translate high-level code into machine code that can be executed on the target hardware. One common issue that arises during this process is the "out of memory"…
Cortex-A53 FIQ Exception During Bare Metal Boot in init_libc When booting a Cortex-A53 processor in bare metal mode, a Fast Interrupt Request (FIQ) exception can occur during the execution of the init_libc function. This issue is particularly prevalent when using the GCC Linaro 4.9 toolchain with glibc 2.14. The FIQ exception is triggered unexpectedly, leading…