Using the NicheStack TCP/IP Stack - Nios II Edition Tutorial

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ID 683574
Date 10/04/2021
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Document Table of Contents
Document Table of Contents x
1. Using the NicheStack TCP/IP Stack - Nios II Edition Tutorial
1. Using the NicheStack TCP/IP Stack - Nios II Edition Tutorial x
1.1. Introduction 1.2. Nichestack Support and Licensing 1.3. Hardware and Software Requirements 1.4. Tutorial Files 1.5. Software Development Flow 1.6. Nios II Simple Socket Server Overview 1.7. Important NicheStack TCP/IP Stack Concepts 1.8. Where to Go Next 1.9. Hardware Setup Details 1.10. Document Revision History for the Using the NicheStack TCP/IP Stack - Nios II Edition Tutorial
1.4. Tutorial Files x
1.4.1. Hardware Design Files 1.4.2. Software Files
1.5. Software Development Flow x
1.5.1. Creating a New Nios II Project 1.5.2. Configuring the BSP 1.5.3. Examining the Nios II Simple Socket Server Project Files 1.5.4. Building and Running the Nios II Simple Socket Server Project 1.5.5. Interacting with the Nios II Simple Socket Server
1.6. Nios II Simple Socket Server Overview x
1.6.1. Software Naming Conventions 1.6.2. Software Architecture 1.6.3. MicroC-OS/II Resources
1.6.3. MicroC-OS/II Resources x
1.6.3.1. Tasks 1.6.3.2. Inter-Task Communication Resources
1.7. Important NicheStack TCP/IP Stack Concepts x
1.7.1. Error Handling 1.7.2. NicheStack TCP/IP Stack Default Task Creation 1.7.3. Creating Tasks that Use the NicheStack TCP/IP Stack Sockets Interface 1.7.4. Task Priorities in the Nios II Simple Socket Server Design 1.7.5. Task Stack Size
1.7.4. Task Priorities in the Nios II Simple Socket Server Design x
1.7.4.1. MicroC/OS-II Internal Tasks 1.7.4.2. NicheStack TCP/IP Stack Internal Tasks 1.7.4.3. Networking Initialization Task 1.7.4.4. User Networking Tasks 1.7.4.5. User Non-Networking Tasks
1.9. Hardware Setup Details x
1.9.1. Network Connection
1. Using the NicheStack TCP/IP Stack - Nios II Edition Tutorial

1.6.2. Software Architecture

The onion diagram shows the architectural layers of a Nios II MicroC/OS-II software application.

Figure 9. Layered Software Model

Each layer encapsulates the specific implementation details of that layer, abstracting the data for the next outer layer. The following list describes each layer:

  • Nios II processor system hardware—The core of the onion diagram represents the Nios II soft core processor and hardware peripherals implemented in the FPGA.
  • Software device drivers—The software device drivers layer contains the software functions that manipulate the Ethernet and hardware peripherals. These drivers know the physical details of the peripheral devices, abstracting those details from the outer layers.
  • HAL API—The Hardware Abstraction Layer (HAL) application programming interface (API) provides a standardized interface to the software device drivers, presenting a POSIX-like API to the outer layers.
  • MicroC/OS-II—The MicroC/OS-II RTOS layer provides multitasking and intertask communication services to the NicheStack TCP/IP Networking Stack and the Nios II Simple Socket Server.
  • NicheStack TCP/IP Stack software component—The NicheStack TCP/IP Stack software component layer provides networking services to the application layer and application-specific system initialization layer through the sockets API.
  • Application-specific system initialization—The application-specific system initialization layer includes the MicroC/OS-II and NicheStack TCP/IP Stack software component initialization functions invoked from main(), as well as creates all application tasks, and all the semaphores, queue, and event flag RTOS inter-task communication resources.
  • Application—The outermost application layer contains the Nios II Simple Socket Server task and LED management tasks.

The "Nios II Simple Socket Server Data Flow Diagram" shows the structure of the design example described in the “Introduction” section. The sections following the figure describe the tasks in the figure.

Figure 10. Nios II Simple Socket Server Data Flow Diagram

The figure shows the state of the system after initialization. When the NicheStack TCP/IP Stack software component receives an Ethernet packet that contains an LED command sent from a telnet client program, the NicheStack TCP/IP Stack processes the incoming Ethernet packet with the TCP/IP protocol and presents the data packet to the socket server task using the sockets API. The LED management tasks then extract and post the LED command contained in the data packet to the LED command queue for processing.

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