ARM Cortex-A53 Tarmac Trace Generation in Gate-Level Simulation The generation of Tarmac traces during gate-level simulation for ARM Cortex-A53 processors is a complex but critical task for debugging and performance analysis. Tarmac traces provide a detailed log of the processor’s execution, including instruction flow, register updates, and memory accesses. While Tarmac traces are typically generated…
Synchronous Exception SPx During MMU Enable in BL1 Stage The issue described involves a failure during the reboot process on an ARM Fixed Virtual Platform (FVP) RDV2 platform. Specifically, the failure occurs in the BL1 stage when attempting to enable the Memory Management Unit (MMU) in EL3 mode. The failure manifests as a Synchronous Exception…
AXI-5 Write Transaction Response Timing Constraints The AMBA AXI-5 protocol defines strict timing requirements for write transactions, particularly concerning the assertion of the BVALID signal relative to WLAST. The core issue revolves around whether BVALID can be asserted in the same clock cycle as WLAST during a write transaction. According to the AXI-5 specification (version…
PSTATE Capture During Denied Power State Transitions In the AMBA Low Power Interface (LPI) specification, the capture of PSTATE (Power State) during specific conditions involving PREQ (Power Request) and PDENY (Power Deny) signals is a critical aspect of power management. The specification outlines that PSTATE can be captured when a request is denied, specifically when…
HRDATA, HREADY, and HRESP Sampling Timing in AMBA AHB The AMBA AHB protocol is a widely used on-chip bus standard for high-performance systems, particularly in ARM-based SoCs. One of the most critical aspects of AHB is the timing of signal sampling, especially for HRDATA, HREADY, and HRESP. These signals are essential for ensuring correct data…
AXI4 Narrow Transfer Misalignment in 64-bit to 32-bit Bus Conversion The core issue revolves around the misalignment and incorrect handling of the AXI4 WSTRB (Write Strobe) signal during narrow transfers from a 64-bit master to a 32-bit slave. The master is configured to perform a burst transfer with specific AWLEN, AWSIZE, and AWBURST settings, but…
AHB Burst Transaction Last Transfer Error Scenarios and Protocol Implications In Advanced High-performance Bus (AHB) protocols, burst transactions are a fundamental mechanism for efficient data transfer between masters and slaves. However, handling errors during the last transfer of a burst transaction introduces complexities due to the pipelined nature of the AHB protocol. The core issue…
WriteUnique Issuance During Cache Line Eviction in ARM CHI Protocol The ARM Coherent Hub Interface (CHI) protocol is designed to ensure cache coherency and efficient data transfers between Request Nodes (RNs) and Home Nodes (HNs). A critical scenario arises when a cache line is being evicted, and a WriteUnique transaction is issued by an RN…
AHB-to-APB Bridge Narrow Burst Transfer Behavior with HSIZE=0 The core issue revolves around the behavior of an AHB-to-APB bridge during narrow burst transfers, specifically when the AHB master initiates a read burst incremental transfer with HSIZE=0 (byte transfer) to an APB slave that is word-addressable. The AHB master expects byte-level granularity in its transactions, while…
GIC400 nIRQ Output Failure and GICD_ISENABLER Address Misconfiguration The issue revolves around the incorrect configuration of the GICD_ISENABLER register address in the ARM GIC400, leading to the failure of nIRQ and nFIQ signal generation. The user has configured the GIC400 to handle two IRQ signals (IRQ0 and IRQ1) and expects the GIC400 to output nIRQ…