ARM AArch64 Exception Vector Table Structure and IRQ Handler Placement The ARM AArch64 architecture defines a fixed exception vector table with specific offsets for different exception types, including IRQ (Interrupt Request) and FIQ (Fast Interrupt Request). Each vector in the table is 0x80 bytes in size, providing a limited space for the handler code. The…
NEON Intrinsics vs. Plain C XOR Performance on Cortex-A72 The performance discrepancy between NEON intrinsics and plain C code for XOR operations on the ARM Cortex-A72 processor is a nuanced issue that requires a deep dive into the architecture, instruction latency, and throughput characteristics. The Cortex-A72, found in the Raspberry Pi 4, is a high-performance…
Complex Number Operations and ARM NEON Intrinsics: Performance Challenges Complex number operations are a cornerstone of many signal processing algorithms, including Fast Fourier Transforms (FFT), digital filters, and matrix operations. ARM NEON intrinsics provide a powerful way to accelerate these operations on ARM Cortex-A and Cortex-M processors. However, leveraging NEON intrinsics for complex number operations,…
ARM Cortex-M33 DWT Watchpoint Configuration and DebugMon_Handler Challenges The ARM Cortex-M33 processor provides a powerful Debug Watchpoint and Trace (DWT) unit, which can be used to monitor memory accesses and trigger debug events. However, configuring the DWT watchpoints to accurately capture the instruction and memory address that triggered a debug event can be challenging. The…
Cortex-M7 Hardfaults Triggered by Unaligned Memory Access and Fault Status Register Analysis The Cortex-M7 microcontroller, specifically the STM32F722 variant, is experiencing random HardFaults that occur at various points in the code execution, including during stack initialization and within the main loop. The HardFaults are characterized by the FORCED bit in the HardFault Status Register (HFSR)…
ARM Cortex-M4 Debug Interface Initialization Failure The error message "Stellaris ICDI Error: Could not initialize target device! Please power cycle the board and try again" is a common issue encountered when working with the TM4C1294XL evaluation board using the Keil IDE and the onboard Stellaris In-Circuit Debug Interface (ICDI). This error typically occurs during the…
Cortex-R Longer Pipelines and Real-Time Interrupt Latency Challenges The ARM Cortex-R series, designed for real-time applications, features longer pipelines compared to the Cortex-M series. While Cortex-M processors typically employ a 3-stage pipeline, Cortex-R processors, such as the R4 and R7, utilize 8-stage and 11-stage pipelines, respectively. This architectural difference raises questions about the impact of…
ARMv7l PyArmNN Backend Support Error on 32-bit Debian Stretch The issue at hand revolves around the inability of PyArmNN to utilize supported backends (CpuACC and CpuRef) on a 32-bit ARMv7l architecture running Debian Stretch 9. The error message indicates that none of the backends are supported, which prevents the execution of a Python-based fire detection…
ARM Cortex-M55 Freeze on Entry to main() at -O0 Optimization Level The issue at hand involves the ARM Corstone SSE-300 MPS3 simulator freezing upon entry to the main() function when the code is compiled with the -O0 optimization level. This behavior is particularly perplexing because the same code executes without issues when compiled with -O3…
Standard C Library Functions Execution in External Flash Causing Performance Bottlenecks In ARM-based SoC designs, the execution of standard C library functions such as memcpy, sin, and others in external flash memory can lead to significant performance degradation. This is primarily due to the slower access times and higher latency associated with external flash compared…