Author: System on Chips

ARM AXI Protocol Support for Unaligned Transfers The ARM AXI (Advanced eXtensible Interface) protocol is designed to support high-performance, high-frequency system-on-chip (SoC) designs. One of its key features is the ability to handle unaligned transfers, which are memory accesses that do not align with the natural boundaries of the data bus width. For example, a…

APB PADDR: Addressing Peripheral Registers in AMBA Protocol The Advanced Peripheral Bus (APB) is a key component of the ARM Advanced Microcontroller Bus Architecture (AMBA) protocol family, designed for low-power, low-complexity peripheral communication. At the heart of APB lies the PADDR signal, which serves as the address bus for selecting specific registers within a peripheral….

Application-Triggered Simulation Stop Requirement in Corstone-300 MPS3 FVP In the context of ARM-based SoC verification, particularly when using the Corstone-300 MPS3 Fixed Virtual Platform (FVP), a common challenge arises when attempting to trigger a simulation stop directly from the application code. This requirement is critical for automating test suites, ensuring that the simulation terminates cleanly…

Secure State Verification in ARMv8 AArch64: The Challenge of Proving Secure EL1 Execution In ARMv8 AArch64 architectures, the distinction between secure and non-secure states is fundamental to the TrustZone security model. The secure state is designed to provide a trusted execution environment (TEE) for sensitive operations, while the non-secure state handles general-purpose tasks. However, verifying…

CoreSight Debug and Trace Support for ThunderX2 Server Architecture The integration of ARM CoreSight debug and trace technology with the ThunderX2 server architecture presents a complex challenge due to the differences in architectural paradigms and the specific requirements of the ThunderX2 platform. CoreSight, a sophisticated debug and trace solution, is designed primarily for ARM-based systems,…

ARM Cortex-M55 Freeze at main() with -O0 Optimization The issue described involves the Corstone SSE-300 FVP (Fixed Virtual Platform) simulator, where the system freezes upon entering the main() function when compiled with -O0 optimization, but operates correctly with -O3 optimization. This behavior suggests a critical dependency on compiler optimizations, which may mask underlying issues in…

ARM Cortex-M4 Zero-Initialized Data Allocation in Minimal Keil Project When compiling an empty main function for the STM32F103C8 microcontroller using Keil ARM, the program size report indicates a surprisingly large Zero-Initialized (ZI) data section. Specifically, the output shows: Code: 648 bytes RO-data: 252 bytes RW-data: 0 bytes ZI-data: 1632 bytes The ZI-data section, which represents…

AHB Slave HREADY Signal Role in Address and Data Phases The HREADY signal in AHB (Advanced High-performance Bus) protocols plays a critical role in managing the timing and flow of data transfers between masters and slaves. In a multi-master system, understanding the behavior of HREADY during both the address and data phases is essential for…

AHB ERROR Response and Transfer Continuation Scenarios In the ARM AMBA AHB protocol, the handling of ERROR responses during burst transfers is a critical aspect of ensuring robust communication between masters and slaves. When a slave responds with an ERROR, the master has the option to either cancel the remaining transfers in the burst or…

AHB Pipelined Transfers: Address and Data Phase Overlap in Multi-Slave Systems In Advanced High-performance Bus (AHB) systems, pipelining is a fundamental feature that allows for efficient data transfer between masters and slaves. The scenario described involves a single AHB master initiating back-to-back transactions to two different slaves, Slave1 and Slave2. The first transaction targets address…