Core of the host, but its function is limited to providing programming interfaces, for example, use the structures usb_gadget_ops and usb_ep_ops to re-encapsulate the device controller driver operation function and Endpoint operation function. Specifically, the register function usb_gadget_register_driver of the Gadget driver is provided directly by the device controller (UDC) driver to bind the UDC to the gadget driver. This increases the dependency
Important USB keywords:
1. endpoint: a data buffer zone located on a USB device or host. It is used to store and send various USB data. Each endpoint has a unique fixed address, has different transmission features (such as input, output, configuration, and batch transmission)
2. frame: the concept of time. In USB, a frame is 1 ms. It is an independent unit and contains a series of bus actions. USB divides o
: device descriptor, configuration descriptor, string descriptor, interface descriptor, and Endpoint descriptor.(2) a USB device can be regarded as a device that provides multiple serial ports. According to the USB specification, each serial port is called an endpoint to communicate with this endpoint, we need to open the connection to this
Vector concept:
If the endpoint of a line segment is ordered, we convert this line segment into a directed line segment ).If the start point P1 of the directed line P1P2 is at the coordinate origin, we can call it vector P2.
Vector addition and subtraction:
Set two-dimensional vector p = (x1, Y1), q = (X2, Y2 ),Vector Addition is defined as: p + q = (X1 + X2, Y1 + y2 ),Vector Subtraction is defined as p-q = (x1-X2, Y1-Y2 ).Obviously, p + q = q + p, p-
2.6. endpoints, pipelines, and interfaces
These three concepts are confusing during USB development. For USB operations in real environments, endpoints, pipelines, and interfaces cannot be ignored. The relationship between these three concepts is 2-6-1;
The USB physical endpoint. In the NXP lpc2478 USB, there are up to 32 physical endpoints, each endpoint from 0 to 31 has a fixed transmission mode (I/out).
Concept of vector:
If the endpoint of a line segment is ordered, we convert this line segment into a directed line segment ).If the start point P1 of the directed line P1P2 is at the coordinate origin, we can call it vector P2.
Vector addition and subtraction:
Set two-dimensional vector p = (x1, Y1), q = (X2, Y2 ),Vector Addition is defined as: p + q = (X1 + X2, Y1 + y2 ),Vector Subtraction is defined as p-q = (x1-X2, Y1-Y2 ).Obviously, p + q =
the management system. Therefore, the communication task must be delegated to different components. In terms of WCF, this component is called a WCF Service. In a more general sense, the WFC service is the software responsible for communicating with the outside world.
A WCF Service consists of the following three parts:
Service Class: A class marked with the [servicecontract] attribute, which may contain multiple methods. Except for marking some unique attributes of WCF, this class is no d
indicates no device protocol is used. 8 , // The maximum packet length supported by byte bmaxpacketsize0 endpoint 0, 0x04d8 , // Supplier ID of word idvendor USB device 0x003f , // Word idproduct USB product ID Zero X 0002 , // BCD code indicates the version number of the USB device, which is specified by the supplier. 0x01 , // Word bcddevice supplier string descriptor index value 0x02 , // Byte imanufacturer product string descriptor ind
The previous section describes the basic use of the Requests.get () method, and this section describes the use of the Requests.post () method:This article directory:I. Definition of methodsSecond, the Post method is simple to use1. Post with Data2. Post with header3. Post with JSON4, with the parameter of the post5, ordinary file upload6. Customized File Upload7, multi-File uploadFirst, the method definition:1, to the official document went to the next requests.post () method definition, as foll
Given a graph to find the shortest path of an endpoint (goal) to the rest of the endpoint or an endpoint, the easiest way to think of it is to take advantage of DFS, assuming that the average path from the beginning to an endpoint is N, the average adjacency endpoint for eac
Basic class, copy down the direct call on the line:Using System;Using System.IO;Using System.Net;Using System.Text;public enum Httpverb{Get,//method commonly used on this kind of, of course you can also add other get: Get post: Modify put: Write Delete: deletePOST,PUT,DELETE}Namespace Httputils{public class Restclient{public string EndPoint {get; set;}//Requested URL address eg:http://215.23.12.45:8080/order/order_id=1isdel=0Public Httpverb method {ge
Socket SocketsBoost.asio has three types of socket classes: IP::TCP,IP::UDP and ip::icmp, all of which are extensible. You can create your own socket class, although it is slightly more complex to do. If you really want to do this, you can refer to BOOST/ASIO/IP/TCP.HPP,BOOST/ASIO/IP/UDP.HPP and boost/asio/ip/icmp.hpp. They are very small classes that use typedef keywords internally.You can use the IP::TCP,IP::UDP and IP::ICMP classes as a placeholder; You can access the methods of classes and c
I. Linux USB driver levels
1. devices, configurations, interfaces, and endpointsThe logical organization of a USB device consists of four layers: device, configuration, interface, and endpoint.
A device usually has one or more configurations:
Each USB device provides different levels of configuration information, which can contain one or more configurations, different Configurations enable devices to exhibit different combinations of functions (
functionsThis kind of composite device includes the functions that has only one interface, such as HID+MSD.The default endpoint (endpoint 0) is a shared by all functions.Each function has a interface only, to handle class-specific requests, control commands and data.The interface and endpoint settings are function specific.Figure 3-1. USB Composite Device with S
. The main function of Contract is to expose all valid methods provided by a WCF Service. Contract converts each method into a corresponding message.
C solved: What functionalities do the Service provide?
3. Endpoint)
WCF enables communication between applications in the network system. The communication between applications is implemented by an Endpoint. In the actual example above, A, B, and C are compo
1. Why do we need to get the metadata on client side? Sometimes the client need to programmatically verify whether a participant endpoint (identified by its address) supports a participant contract/operations. for example, imagine an application where the End User specifies or configures the application during setup to consume and interact with a service. if the service does not support the required contracts, the application shocould alert the user t
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Configuration
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System. servicemodel
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The services element contains the Configuration Requirements of all services resident in the application.
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Services
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Configuration of each ServiceAttribute description:Name-specify the service configuration for which the service is targeted. It is a fully qualified name for a service that implements certain contract.(Namespace. type name), after serv
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