Author: System on Chips

ARM Cortex-A9 L1 Data Cache Miss Rate Anomalies During Array Access When profiling the Level 1 data cache (L1d) on an ARM Cortex-A9 processor, particularly on a Zynq-7020 device, unexpected cache miss rates can occur during array iteration. The issue manifests when attempting to measure cache utilization using the Performance Monitoring Unit (PMU) counters. Specifically,…

ARM Cortex-M4 Immediate Value Encoding Limitations in MOV Instructions The ARM Cortex-M4 processor, as part of the ARMv7-M architecture, employs a specific instruction set that includes both Thumb and Thumb-2 instructions. One of the key features of this architecture is its ability to handle immediate values in data processing instructions, such as the MOV instruction….

Interrupt Vector Table Modification Challenges in 8051 Simulation The core issue revolves around the modification of the interrupt vector table for an 8051 CPU within the Keil debugger environment. The original interrupt vectors are predefined and hardcoded within the 8051 architecture, and the user aims to add custom interrupt vectors for simulation purposes. The challenge…

ARM Cortex-A53 Bootloader and Android Compatibility Issues The ARM Cortex-A53 is a highly efficient 64-bit processor core designed for a wide range of applications, from mobile devices to embedded systems. One of the common use cases for the Cortex-A53 is running Android, a popular operating system for mobile and embedded devices. However, installing Android on…

ARM Cortex-A53 MMU Section Mapping with Non-Identity Offset The core issue revolves around configuring the ARM Cortex-A53 Memory Management Unit (MMU) to map a virtual address range to a physical address range with a non-identity offset. Specifically, the goal is to map the virtual address range 0xFFFF000000000000 to 0xFFFF000040000000 to the physical address range 0x40000000…

ARM Cortex-A53 Core Block Diagram Requirements for FMEA Analysis The ARM Cortex-A53 is a highly efficient, low-power processor core that is widely used in embedded systems and mobile devices. It is part of the ARMv8-A architecture and is designed to deliver a balance between performance and power efficiency. However, when performing a Failure Modes and…

ARM64 Subroutine Call and Return Mechanism with BL, BLR, and BR Instructions The core issue revolves around the misuse of the ARM64 BL, BLR, and BR instructions in inline assembly, leading to incorrect subroutine calls and returns. The BL (Branch with Link) instruction is used to call a subroutine, storing the return address in the…

ARM Instruction Encoding: Decoding "sf" and "hw" Fields The ARM architecture, known for its efficiency and versatility, employs a highly structured instruction encoding scheme. Within this scheme, certain fields in the instruction encoding diagrams are abbreviated, such as "sf" and "hw". These abbreviations are critical for understanding how instructions are processed and executed by the…

Floating-Point Computation Consistency in ARM Cortex-A53 vs. Cortex-M4F When dealing with floating-point computations in embedded systems, especially across different ARM processor families, understanding the nuances of how floating-point operations are handled is crucial. The ARM Cortex-A53 and ARM Cortex-M4F both support single-precision floating-point operations (FP32) under the IEEE 754 standard, but there are several factors…

ARM CCA Realm VM Device Assignment Limitations in Current RME Architecture The ARM Confidential Compute Architecture (CCA) and its Realm Management Extension (RME) introduce a robust framework for secure virtualization, enabling the creation of isolated execution environments known as Realms. These Realms are designed to protect sensitive workloads from both the hypervisor and the non-secure…