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7.4.4 HcRhPortStatus[1:NDP] Register
字段功能说明 The HcRhPortStatus[1:NDP] register is used to control and report port events on a per-port basis. NumberDownstreamPorts represents the number of HcRhPortStatus registers t... -
3.2 Data Transfer Types
There are four data transfer types defined in USB. Each type is optimized to match the service requirements between the client software and the USB device. The four types are:· In... -
3.1 Introduction
Figure 3-1 shows four main focus areas of a Universal Serial Bus (USB) system. These areas are the Client Software/USB Driver, Host Controller Driver (HCD), Host Controller (HC), ... -
7.4.3 HcRhStatus Register
图7-21：HcRhStatus寄存器结构说明 寄存器位布局（31:0） 字段功能详述 7.4.3 HcRhStatus Register The HcRhStatus register is divided into two parts. The lower word of a Dword represents the Hub Status fi... -
11.15.1 Standard Descriptors
Device Descriptor 设备描述符 Interface Descriptor 接口描述符 Configuration Descriptor 配置描述符 Endpoint Descriptor (for Status Change Endpoint) 端点描述符（用于状态变更端点） The hub class pre-define... -
循序渐进理解恒流源电路
由 电阻 构成的 恒流源 1个 三极管 简单 三极管 恒流源 改进 2个三极管 改进1： 改进2: 由 电阻 构成的 恒流源 缺点: 高压电源 不常用 大电阻 会引起功耗大 灵活性差(如果想得到不同的供电电流，需要不停的更换大电阻) 1个 三极管 简单 三极管 恒流源 让三极管工作在放大区时，在给定的Ube下，其... -
7.1.4 HcInterruptStatus Register
This register provides status on various events that cause hardware interrupts. When an event occurs, Host Controller sets the corresponding bit in this register. When a bit becom... -
7.2.2 HcPeriodCurrentED
The HcPeriodCurrentED register contains the physical address of the current Isochronous or Interrupt Endpoint Descriptor. HcPeriodCurrentED寄存器包含当前等时或中断端点描述符的物理地址。 图 7-8：H... -
4.4.2.3 HccaDoneHead
When a TD is complete (with or without an error) it is unlinked from the queue that it is on and linked to the Done Queue. The Host Controller maintains a physical pointer to the ...