Understanding the Challenge of Exception Level Transition from EL1 to EL0 Transitioning between Exception Levels (ELs) in ARM64 architectures, particularly from EL1 to EL0, is a critical operation in bare-metal environments. This transition is essential for scenarios such as running user-space applications (EL0) from a kernel or hypervisor (EL1). The process involves manipulating specific system…
Cortex-A53 WFE Exit Latency and Its Impact on Spinlock Performance The Cortex-A53 processor, a popular choice for energy-efficient applications, implements the ARMv8-A architecture and is widely used in embedded systems and mobile devices. One of its key features is the ability to enter low-power states using the Wait For Event (WFE) instruction. This instruction allows…
ARM Cortex-A75 Neon Engine Performance Compared to Intel SSE The performance discrepancy between ARM Neon and Intel SSE intrinsics for 16-bit array addition operations is a multifaceted issue that requires a deep dive into the architectural differences, instruction set capabilities, and execution environments of both platforms. The observed speed-up of approximately 6x for Intel SSE…
Cortex-A35 Parameter Reconfiguration Challenges in System Builder and Socrates Tool Reconfiguring parameters for the ARM Cortex-A35 processor within a System-on-Chip (SoC) design using tools like System Builder and Socrates can be a complex task, especially when documentation is sparse or unclear. The Cortex-A35 is a highly configurable processor, and its parameters—such as cache sizes, memory…
Understanding Cortex-M33 Tracing: ETM, ETB, and MTB Interactions The Cortex-M33 processor, part of ARM’s Cortex-M series, is designed for embedded systems requiring high performance and security. One of its advanced features is its tracing capabilities, which are critical for debugging and performance analysis. The Embedded Trace Macrocell (ETM), Embedded Trace Buffer (ETB), and Micro Trace…
ARM Cortex-M4 System Reset Failure via NVIC_SystemReset Function The ARM Cortex-M4 microcontroller is designed to provide a reliable and efficient platform for embedded systems. One of its critical features is the ability to perform a system reset, which is often required during firmware updates, error recovery, or system reinitialization. However, in some cases, the NVIC_SystemReset…
External Flash Selection and Integration with Cortex-M0 When integrating an ARM Cortex-M0 processor with external flash memory, the first step is selecting a compatible flash device. The Cortex-M0, being a low-power, 32-bit RISC processor, is often used in embedded systems where external flash memory is required for storing firmware or data. Commercial external flash memories,…
SPI Receiver Fails to Enable with SYNCBUSY.CTRLB Stuck High The issue at hand involves the SPI receiver on an ATSAMD21G18A (Cortex-M0) microcontroller failing to enable, with the SYNCBUSY.CTRLB bit persistently set to one. This prevents the receiver from being enabled, as indicated by the CTRLB.RXEN bit not being set correctly. The problem manifests after enabling…
UART Data Corruption with Dummy Characters in Nuvoton MS51FB9AE The issue described involves the reception of corrupted UART data on the Nuvoton MS51FB9AE microcontroller, which is based on the ARM Cortex-M architecture. The user reports that while testing a UART loopback program, dummy characters (e.g., "⸮") appear intermittently in the received data stream. For example,…
Synchronous Data Abort and FIQ Timing in Cortex-R5F Memory Access In the ARM Cortex-R5F processor, a scenario can arise where a memory access operation, such as a read from L2 memory, triggers both a synchronous data abort and a Fast Interrupt Request (FIQ) nearly simultaneously. This situation is particularly observed when the memory subsystem is…