ARM Neoverse N2 SVE Vector Length Configuration Mismatch at EL0 The ARM Neoverse N2 processor, a high-performance core designed for infrastructure and cloud workloads, implements the Scalable Vector Extension (SVE) as part of its architecture. SVE allows for variable vector lengths, which can be configured through system registers such as ZCR_EL3, ZCR_EL2, and ZCR_EL1. However,…
ARM Cortex-A53 Core Shutdown During AT S12E1R Instruction Execution The ARM Cortex-A53 processor is a widely used 64-bit core in embedded systems, known for its efficiency and performance. However, when implementing a bare-metal hypervisor, developers may encounter a critical issue where the core shuts down or becomes unresponsive during the execution of the AT S12E1R…
PHP 5.6 and Xalan: Criticality in Corstone-201 RTL Generation The generation of the top-level RTL for the Corstone-201 subsystem is a complex process that relies on a variety of tools and dependencies. Among these, PHP 5.6 and Xalan have been identified as potential bottlenecks due to installation challenges on RHEL 8.4. PHP 5.6 is a…
DMA330 Microcode Limitations for Linked-List DMA Transfers The DMA330, also known as the PL330, is a highly configurable DMA controller widely used in ARM-based systems. It is designed to handle complex data transfer tasks with minimal CPU intervention. However, programming the DMA330 to perform linked-list-style DMA transfers, particularly for circular buffer implementations, presents unique challenges…
SWD Communication Random Read Values Under High Hardware Memory Contention When using Serial Wire Debug (SWD) to read memory locations that are also heavily accessed by hardware, a common issue arises where the SWD interface occasionally returns random or incorrect values. This problem is particularly pronounced in systems where hardware (HW) memory access is given…
ARMv8 Weak Consistency and Address-Data Dependency in Memory Operations ARMv8 architecture employs a weakly consistent memory model, which allows for out-of-order execution of memory operations to optimize performance. This means that the processor may reorder memory accesses unless explicit synchronization instructions, such as Data Synchronization Barrier (DSB) or Data Memory Barrier (DMB), are used to…
ARM AXI4 Protocol: WVALID and AWREADY Timing Dependencies The ARM AXI4 protocol is a widely used on-chip communication standard for high-performance embedded systems. It defines a set of rules and signaling mechanisms for data transfers between managers (masters) and subordinates (slaves). One of the critical aspects of the AXI4 protocol is the timing relationship between…
ARM CHI TXLINK and RXLINK State Transition Deadlock Scenario The issue at hand involves a potential deadlock scenario in the ARM AMBA CHI (Coherent Hub Interface) protocol, specifically concerning the state transitions of the TXLINK and RXLINK during a sequence of transactions involving CompAck, Snoop Request, and Snoop Response. The deadlock arises when the Requester…
ARM Cortex-R52 ECC Implementation for TCMs and Cache Memories The ARM Cortex-R52 processor is widely used in safety-critical applications where error detection and correction are paramount. One of the key features enabling this reliability is Error Correction Code (ECC) for Tightly Coupled Memories (TCMs) and cache memories. ECC is a mechanism that detects and corrects…
SACTIVE Signal Synchronization and Timing Requirements in AMBA CHI The SACTIVE signal in the AMBA CHI (Coherent Hub Interface) protocol plays a critical role in ensuring proper transaction handling and synchronization between components in a system-on-chip (SoC). According to the AMBA CHI Architecture Specification (IHI0050), the SACTIVE signal must be synchronous to the clock (CLK)…