Cortex-A9 Freezing and JTAG Inaccessibility During System Lockup The Cortex-A9 processor, particularly in the Zynq 7000 series, can occasionally experience a critical failure where the system freezes to the point that JTAG debugging becomes inaccessible. This issue is characterized by the inability to halt the processor, extract debug information, or obtain a coherent stack trace….
LPC1800 SPIFI Interface and S25FL256SA Flash Memory Performance Issues The LPC1800 microcontroller, when interfaced with the S25FL256SA flash memory via the SPIFI (Serial Peripheral Interface Flash Interface), exhibits significant performance degradation compared to its operation with the older S25FL064P flash memory. The primary issue is the reduction in code execution speed when using the S25FL256SA…
ARM AXI Master-Slave Transaction Stalls Due to DRAM Clock Failure In ARM-based systems utilizing the AXI (Advanced eXtensible Interface) protocol, a critical issue arises when a master device attempts to initiate a transaction with a DRAM (Dynamic Random-Access Memory) slave, but the DRAM clock is not running. This scenario can lead to system stalls, undefined…
ARM Cortex-M4 FFT Frequency Resolution Limitations in Noisy Environments When working with noisy or distorted signals, accurately determining the dominant frequency using Fast Fourier Transform (FFT) on ARM Cortex-M4 processors can be challenging. The primary issue arises from the inherent limitations of FFT frequency resolution, which is determined by the sampling rate and the number…
ARM MMU Page Table Linking Constraints with Absolute Addressing The ARM Memory Management Unit (MMU) is a critical component in modern ARM architectures, responsible for translating virtual addresses to physical addresses. This translation is facilitated through a hierarchical page table structure, where Level 1 (L1) page table entries point to Level 2 (L2) page tables….
ARM Cortex CPU Known State in Power State Coordination Interface (PSCI) The concept of a "known state" in ARM architectures, particularly within the context of the Power State Coordination Interface (PSCI), is a critical aspect of system power management and reliability. The PSCI specification defines a set of standard interfaces for power management in ARM-based…
ARM CHI Protocol: ReadNoSnpSep and DataSepResp in IHI0050C and IHI0050D The ARM Coherent Hub Interface (CHI) protocol is a critical component in modern ARM-based systems, enabling efficient communication between various system components such as Request Nodes (RN), Slave Nodes (SN), and Integrated Coherent Network (ICN) components. One of the key transactions in the CHI protocol…
CoreSight TMC Buffer Level Mismatch During Trace Capture The CoreSight Trace Memory Controller (TMC) is a critical component in ARM-based systems for capturing and managing trace data, which is essential for debugging and performance analysis. One of the key registers in the TMC is the Current Buffer Level (CBUFLEVEL), which indicates the amount of trace…
ARM Cortex-A55 Retention Mode Transition Challenges in Vmin The ARM Cortex-A55 is a highly efficient mid-range processor core designed for power-sensitive applications, often operating in scenarios where minimizing voltage (Vmin) is critical for power savings. One of the key features of the Cortex-A55 is its ability to transition into retention mode, a low-power state where…
ARM Cortex-A53 Write-Back Cache Behavior and External Memory Access The ARM Cortex-A53 processor, part of the ARMv8-A architecture, is widely used in embedded systems due to its balance of performance and power efficiency. One of its key features is the support for configurable memory attributes, including write-back caching. Write-back caching is a memory optimization technique…