Architectures and Processors

AXI4 Write Data Arriving Before Write Address Due to Register Stage Imbalance In the AXI4 protocol, the relationship between the write address (AW) channel and the write data (W) channel is critical for ensuring correct data transfer and system functionality. A unique characteristic of the AXI4 protocol is that the write data can arrive at…

AHB Master BUSY Transfer Timing Conflict in INCR4 Burst In Advanced High-performance Bus (AHB) systems, the timing of BUSY transfers during burst operations can lead to critical arbitration conflicts, particularly when a BUSY transfer is inserted just before the final transfer in a burst sequence. This issue is especially pronounced in INCR4 bursts, where the…

SMMUv3 Integration and Testing Challenges in Armv8-A Base Platform FVP The System Memory Management Unit version 3 (SMMUv3) is a critical component in modern ARM-based System-on-Chip (SoC) designs, enabling virtualization and secure memory management for peripheral devices. However, integrating and testing an SMMUv3 driver on the Armv8-A Base Platform Fixed Virtual Platform (FVP) presents several…

ARM Keil C Compiler Warning: Incompatible Argument Types in sprintf Function The issue at hand revolves around a specific compiler warning (#167-D) generated by the ARM Keil C compiler when using the sprintf function. The warning indicates that the argument of type BYTE * is incompatible with the parameter of type char *restrict. This warning…

Cortex-A5x4 FVP Missing in DS-5 Debug Configuration Interface The Cortex-A5x4 Fixed Virtual Platform (FVP) is a critical tool for simulating and debugging ARM-based SoC designs. However, after installation, users may encounter an issue where the Cortex-A5x4 FVP does not appear in the DS-5 Debug Configuration interface. This problem can halt development workflows, as the FVP…

SRAM as Flash Substitute in ARM SoC Design In the context of ARM-based System-on-Chip (SoC) design, the decision to replace flash memory with SRAM is driven by several factors, including process limitations, design complexity, and power management constraints. Flash memory typically requires additional on-chip modules such as DC-to-DC converters and power management control features, which…

ARM and eFPGA Synchronization Complexity in DC/DC Control Applications The integration of ARM-based microcontrollers (MCUs) with embedded FPGA (eFPGA) fabrics in DC/DC controller SoCs presents a unique set of challenges, particularly in achieving synchronization between the high-speed ARM MCU and the eFPGA fabric. DC/DC controllers require precise timing and control to regulate voltage conversion efficiently,…

AMBA 5 CHI Multi-Flit Message Interleaving Constraints The AMBA 5 CHI (Coherent Hub Interface) protocol is designed to facilitate high-performance, scalable communication between components in a system-on-chip (SoC). One of the key aspects of the protocol is the handling of multi-flit messages, which are messages that span multiple flits (flow control units). A critical question…

MPAM Cache Partitioning Configuration and FVP Model Discrepancy The Memory Partitioning and Monitoring (MPAM) feature in ARM-based systems is designed to provide fine-grained control over cache and memory bandwidth partitioning. This is particularly useful in multi-tenant systems where different applications or virtual machines require isolated and guaranteed access to shared resources. The MPAM architecture defines…

APB Protocol PENABLE Signal Usage and Its Necessity The Advanced Peripheral Bus (APB) is part of the ARM AMBA protocol family, designed for low-power, low-complexity peripheral interfacing. One of the key signals in the APB protocol is PENABLE, which plays a critical role in the two-cycle transfer mechanism of APB. The PENABLE signal is used…