Interrupt Handling

Embedded Programming: Fast Context Switching Based on cpost with Code Link at the End

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Embedded Programming: Fast Context Switching Based on cpost with Code Link at the End

The demands of embedded development programming are ever-changing. To achieve system stability and code reusability, high cohesion and low coupling must be maintained.It is generally believed that time-consuming operations cannot be executed within interrupts, as this would affect system stability. For programs with an operating system, interrupt handling can be divided into two parts through … Read more

ESP32 Multicore Programming Techniques: Interrupt Handling Mechanism

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ESP32 Multicore Programming Techniques: Interrupt Handling Mechanism

In the dual-core architecture of the ESP32, the interrupt handling mechanism is key to achieving efficient real-time response. The ESP32 supports multicore interrupt handling (Core 0 and Core 1), but it needs to be combined with FreeRTOS task scheduling and synchronization mechanisms to fully leverage its performance. Below are the core technologies, configuration methods, and … Read more

Design Framework for Thread Prioritization in Embedded Systems

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Design Framework for Thread Prioritization in Embedded Systems

Abstract Real-Time Operating Systems (RTOS) and Operating Systems (OS) both provide the capability to set thread priorities. We assign a unique priority to each thread based on the software functional architecture, thereby creating a hierarchy of threads within the system. However, this principle of assigning unique priorities can lead to issues, as assigning a unique … Read more

Network Troubleshooting in Linux

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Network Troubleshooting in Linux

The packet reception process of the Linux network card is as follows: The network card receives the data packet. The data packet is moved from the network card hardware buffer to the server memory (using DMA, without going through the CPU). A hardware interrupt notifies the CPU to process it. The CPU notifies the kernel … Read more

Windows PCI Device Driver Development Guide: Two Options for Interrupt Handling – DPC vs WorkItem

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Windows PCI Device Driver Development Guide: Two Options for Interrupt Handling - DPC vs WorkItem

In this article (How to Trigger User-Mode Events from Interrupt Handling Functions), we mentioned notifying a user-mode event in the WDF driver’s interrupt handling function using the KeSetEvent function, waking up the user-mode program to read the Timer’s count value. However, since the kernel function KeSetEvent is required to run at an IRQL less than … Read more

Windows PCI Device Driver Development Guide: How to Trigger User-Space Events from Interrupt Handlers

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Windows PCI Device Driver Development Guide: How to Trigger User-Space Events from Interrupt Handlers

In the article on interrupt handling in drivers, we introduced how to add logic for handling periodic Timer interrupts in the driver for our simulated PCIe device. To test the Timer counting functionality, we also created a user-space test program that reads the Timer’s count register every second. While this approach can test whether the … Read more

Guide to Windows PCI Device Driver Development: Interrupt Handling

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Guide to Windows PCI Device Driver Development: Interrupt Handling

In this article, we add a periodic Timer to the PCIe device previously simulated in Qemu. Once this Timer is enabled, it will trigger an MSI interrupt to the Qemu virtual machine every second. To verify that this interrupt function works correctly, we need to add interrupt handling capabilities to the driver for this PCIe … Read more

An Analysis of the Implementation Principles of MSI-X: A Study Based on the Linux Kernel Source Code

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An Analysis of the Implementation Principles of MSI-X: A Study Based on the Linux Kernel Source Code

Recently, while simulating MSI-X interrupts using QEMU, I found that many people do not fully understand MSI-X interrupts. Below, I will analyze this based on the Linux kernel version 6.1.26 source code. 1. MSI-X Specification in the PCIe Protocol 1.1 MSI-X Capability in PCIe Configuration Space Capability According to the PCIe 3.0 specification, the MSI-X … Read more

Detailed Explanation of CPU I/O Capabilities and Peripheral Control Techniques in Assembly Language

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Detailed Explanation of CPU I/O Capabilities and Peripheral Control Techniques in Assembly Language

1. Overview of CPU I/O Capabilities The CPU not only has computational capabilities but also needs to exchange data with external devices, a capability known as I/O (Input/Output) capability. Typical I/O operations in a computer system include: Keyboard input Display output Disk read/write Network communication, etc. 2. Two Core Issues in Peripheral Interaction 1. Peripheral … Read more

Advantages of Cortex-R5F: Low Latency Interrupt Handling

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Advantages of Cortex-R5F: Low Latency Interrupt Handling

The Cortex-R5F is a real-time processor core based on the ARMv7-R architecture, designed for embedded systems that require high reliability and low latency. It is widely used in industrial automation, automotive electronics, and intelligent control.The core advantage of the Cortex-R5F lies in its low latency interrupt handling capability, enabling rapid response to external events while … Read more