ARM Cortex-M Exception Handling: Timing, Interruptibility, and Memory Access Behavior

ARM Cortex-M Exception Handling: Timing, Interruptibility, and Memory Access Behavior

ARM Cortex-M Exception Handling and Instruction Interruptibility The ARM Cortex-M series of processors, particularly the Cortex-M3, Cortex-M4, and Cortex-M7, are widely used in embedded systems due to their efficient exception handling mechanisms. However, understanding when and how exceptions are taken into account, especially in the context of instruction execution and memory access, is critical for…

DynamIQ Cluster Fabric Topology: Crossbar vs. Ring/Mesh Interconnect

DynamIQ Cluster Fabric Topology: Crossbar vs. Ring/Mesh Interconnect

ARM DynamIQ Cluster Fabric Topology Overview The ARM DynamIQ cluster represents a significant evolution in ARM’s multi-core processor architecture, particularly in how cores communicate and share resources. At the heart of this architecture lies the fabric topology, which determines the efficiency and scalability of data transfer between cores, caches, and other system components. The fabric…

Non-Secure Callable (NSC) Functions in ARM TrustZone for Secure and Non-Secure Code Interaction

Non-Secure Callable (NSC) Functions in ARM TrustZone for Secure and Non-Secure Code Interaction

Non-Secure Callable (NSC) Functions in ARM TrustZone: Bridging Secure and Non-Secure Worlds The ARM TrustZone technology provides a robust security framework for embedded systems by partitioning the system into secure and non-secure worlds. This partitioning ensures that sensitive code and data are isolated from non-secure applications, thereby protecting critical system resources from unauthorized access. However,…

ARM Cortex-M23 Secure to Non-Secure Interrupt Handling HardFault Analysis

ARM Cortex-M23 Secure to Non-Secure Interrupt Handling HardFault Analysis

ARM Cortex-M23 Interrupt Target Configuration and HardFault During Secure-to-Non-Secure Transition The ARM Cortex-M23 processor, with its TrustZone security extension, introduces a robust mechanism for separating secure and non-secure worlds. However, this separation adds complexity to interrupt handling, especially when transitioning interrupts from the secure world to the non-secure world. A common issue arises when configuring…

ARM Cortex-M7 MIPS Calculation and Performance Benchmarks

ARM Cortex-M7 MIPS Calculation and Performance Benchmarks

ARM Cortex-M7 Peak MIPS and Real-World Performance Discrepancies The ARM Cortex-M7 is a high-performance microcontroller core designed for embedded applications requiring significant computational power. One of the key metrics often used to evaluate the performance of such processors is MIPS (Million Instructions Per Second). However, calculating MIPS for the Cortex-M7 is not straightforward due to…

Probing Power Measurement on ARM Cortex-A9 Using PAPI Tool

Probing Power Measurement on ARM Cortex-A9 Using PAPI Tool

ARM Cortex-A9 Power Measurement Challenges with PAPI The ARM Cortex-A9 processor, part of the ARMv7-A architecture, is widely used in embedded systems for its balance of performance and power efficiency. However, measuring power consumption on such processors, especially when running cryptographic algorithms or other compute-intensive tasks, can be challenging. The Performance Application Programming Interface (PAPI)…

AArch64 TLB Maintenance: Break-Before-Make Requirements for Block Demotion

AArch64 TLB Maintenance: Break-Before-Make Requirements for Block Demotion

ARM Cortex-A53 TLB Coherency Issues During Block-to-Table Demotion In ARMv8-A architectures, particularly when dealing with AArch64, the Translation Lookaside Buffer (TLB) plays a critical role in managing virtual-to-physical address translations. One of the more nuanced challenges arises when transitioning from a block mapping to a table mapping, especially in a multi-processing element (PE) environment. This…

ARMv7-A STR Instruction Behavior and Cache Write-Back Granule Analysis

ARMv7-A STR Instruction Behavior and Cache Write-Back Granule Analysis

ARM Cortex-A9 Cache Write-Back Granule and STR Instruction Impact The ARMv7-A architecture, particularly when implemented in processors like the Cortex-A9, introduces nuanced behaviors when executing store instructions such as STR. The STR r1, [r0] instruction writes the contents of register r1 to the memory address specified by register r0. However, the interaction between this instruction…

ARMv8.2-A Full Implementation and SVE Support in ARM Cortex-A75

ARMv8.2-A Full Implementation and SVE Support in ARM Cortex-A75

ARMv8.2-A Architecture: Mandatory Features and Optional Extensions The ARMv8.2-A architecture is an extension of the ARMv8-A architecture, introducing several mandatory features and optional extensions that enhance the capabilities of ARM processors. A full implementation of ARMv8.2-A requires compliance with both the mandatory architectural features and any additional requirements specified in the ARM Architecture Reference Manual….

Extra Cycle in Cortex-M4 DWT Cycle Count Measurement Due to Pipeline Effects and Memory Access

Extra Cycle in Cortex-M4 DWT Cycle Count Measurement Due to Pipeline Effects and Memory Access

Cortex-M4 Pipeline Behavior and DWT Cycle Counter Measurement Anomaly The Cortex-M4 processor, like many modern microprocessors, employs a pipelined architecture to enhance performance. This architecture allows multiple instructions to be processed simultaneously, albeit at different stages of execution. While this design significantly boosts throughput, it introduces complexities when measuring precise instruction cycle counts, especially when…