When it is registered with the generic name 'USB Serial Device' it uses the Windows driver. The linked document ' Honeywell USB serial driver for Windows 10 ' provide some guidance on the installation of the HSM USB serial driver, and with the determination of the driver in use.

In computing, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer.^[1] A driver provides a software interface to hardware devices, enabling operating systems and other computer programs to access hardware functions without needing to know precise details about the hardware being used.

A driver communicates with the device through the computer bus or communications subsystem to which the hardware connects. When a calling program invokes a routine in the driver, the driver issues commands to the device. Once the device sends data back to the driver, the driver may invoke routines in the original calling program. Drivers are hardware dependent and operating-system-specific. They usually provide the interrupt handling required for any necessary asynchronous time-dependent hardware interface.^[2]

Purpose[edit]

The main purpose of device drivers is to provide abstraction by acting as a translator between a hardware device and the applications or operating systems that use it.^[1] Programmers can write higher-level application code independently of whatever specific hardware the end-user is using.For example, a high-level application for interacting with a serial port may simply have two functions for 'send data' and 'receive data'. At a lower level, a device driver implementing these functions would communicate to the particular serial port controller installed on a user's computer. The commands needed to control a 16550 UART are much different from the commands needed to control an FTDI serial port converter, but each hardware-specific device driver abstracts these details into the same (or similar) software interface.

Development[edit]

Writing a device driver requires an in-depth understanding of how the hardware and the software works for a given platform function. Because drivers require low-level access to hardware functions in order to operate, drivers typically operate in a highly privileged environment and can cause system operational issues if something goes wrong. In contrast, most user-level software on modern operating systems can be stopped without greatly affecting the rest of the system. Even drivers executing in user mode can crash a system if the device is erroneously programmed. These factors make it more difficult and dangerous to diagnose problems.^[3]

Usb Controller Driver For Vista

The task of writing drivers thus usually falls to software engineers or computer engineers who work for hardware-development companies. This is because they have better information than most outsiders about the design of their hardware. Moreover, it was traditionally considered in the hardware manufacturer's interest to guarantee that their clients can use their hardware in an optimum way. Typically, the Logical Device Driver (LDD) is written by the operating system vendor, while the Physical Device Driver (PDD) is implemented by the device vendor. But in recent years non-vendors have written numerous proprietary device drivers, mainly for use with free and open sourceoperating systems. In such cases, it is important that the hardware manufacturer provides information on how the device communicates. Although this information can instead be learned by reverse engineering, this is much more difficult with hardware than it is with software.

Microsoft has attempted to reduce system instability due to poorly written device drivers by creating a new framework for driver development, called Windows Driver Foundation (WDF). This includes User-Mode Driver Framework (UMDF) that encourages development of certain types of drivers—primarily those that implement a message-based protocol for communicating with their devices—as user-mode drivers. If such drivers malfunction, they do not cause system instability. The Kernel-Mode Driver Framework (KMDF) model continues to allow development of kernel-mode device drivers, but attempts to provide standard implementations of functions that are known to cause problems, including cancellation of I/O operations, power management, and plug and play device support.

Apple has an open-source framework for developing drivers on macOS called the I/O Kit.

In Linux environments, programmers can build device drivers as parts of the kernel, separately as loadable modules, or as user-mode drivers (for certain types of devices where kernel interfaces exist, such as for USB devices). Makedev includes a list of the devices in Linux: ttyS (terminal), lp (parallel port), hd (disk), loop, sound (these include mixer, sequencer, dsp, and audio)...^[4]

The Microsoft Windows.sys files and Linux .ko modules contain loadable device drivers. The advantage of loadable device drivers is that they can be loaded only when necessary and then unloaded, thus saving kernel memory.

Kernel mode vs. user mode[edit]

Device drivers, particularly on modernMicrosoft Windows platforms, can run in kernel-mode (Ring 0 on x86 CPUs) or in user-mode (Ring 3 on x86 CPUs).^[5] The primary benefit of running a driver in user mode is improved stability, since a poorly written user mode device driver cannot crash the system by overwriting kernel memory.^[6] On the other hand, user/kernel-mode transitions usually impose a considerable performance overhead, thereby prohibiting user-mode drivers for low latency and high throughput requirements.

Kernel space can be accessed by user module only through the use of system calls. End user programs like the UNIX shell or other GUI-based applications are part of the user space. These applications interact with hardware through kernel supported functions.

Applications[edit]

Because of the diversity of modern hardware and operating systems, drivers operate in many different environments.^[7] Drivers may interface with:

• Local buses of various sorts—in particular, for bus mastering on modern systems
• Low-bandwidthI/O buses of various sorts (for pointing devices such as mice, keyboards, USB, etc.)
• Computer storage devices such as hard disk, CD-ROM, and floppy disk buses (ATA, SATA, SCSI)
• Implementing support for different file systems

Common levels of abstraction for device drivers include:

• For hardware:
  • Interfacing directly
  • Writing to or reading from a device control register
  • Using some higher-level interface (e.g. Video BIOS)
  • Using another lower-level device driver (e.g. file system drivers using disk drivers)
  • Simulating work with hardware, while doing something entirely different^[8]
• For software:
  • Allowing the operating system direct access to hardware resources
  • Implementing only primitives
  • Implementing an interface for non-driver software (e.g. TWAIN)
  • Implementing a language, sometimes quite high-level (e.g. PostScript)

So choosing and installing the correct device drivers for given hardware is often a key component of computer system configuration.^[9]

Virtual device drivers[edit]

Virtual device drivers represent a particular variant of device drivers. They are used to emulate a hardware device, particularly in virtualization environments, for example when a DOS program is run on a Microsoft Windows computer or when a guest operating system is run on, for example, a Xen host. Instead of enabling the guest operating system to dialog with hardware, virtual device drivers take the opposite role and emulates a piece of hardware, so that the guest operating system and its drivers running inside a virtual machine can have the illusion of accessing real hardware. Attempts by the guest operating system to access the hardware are routed to the virtual device driver in the host operating system as e.g., function calls. The virtual device driver can also send simulated processor-level events like interrupts into the virtual machine.

Virtual devices may also operate in a non-virtualized environment. For example, a virtual network adapter is used with a virtual private network, while a virtual disk device is used with iSCSI. A good example for virtual device drivers can be Daemon Tools.

There are several variants of virtual device drivers, such as VxDs, VLMs, and VDDs.

Open source drivers[edit]

• Printers: CUPS
• RAIDs: CCISS^[10] (Compaq Command Interface for SCSI-3 Support^[11])
• Scanners: SANE
• Video: Vidix, Direct Rendering Infrastructure

Solaris descriptions of commonly used device drivers:

• fas: Fast/wide SCSI controller
• hme: Fast (10/100 Mbit/s) Ethernet
• isp: Differential SCSI controllers and the SunSwift card
• glm: (Gigabaud Link Module^[12]) UltraSCSI controllers
• scsi: Small Computer Serial Interface (SCSI) devices
• sf: soc+ or social Fiber Channel Arbitrated Loop (FCAL)
• soc: SPARC Storage Array (SSA) controllers and the control device
• social: Serial optical controllers for FCAL (soc+)

APIs[edit]

• Windows Display Driver Model (WDDM) – the graphic display driver architecture for Windows Vista, Windows 7, Windows 8, and Windows 10.
• Unified Audio Model (UAM)^[13]
• Windows Driver Foundation (WDF)
• Windows Driver Model (WDM)
• Network Driver Interface Specification (NDIS) – a standard network card driver API
• Advanced Linux Sound Architecture (ALSA) – as of 2009 the standard Linux sound-driver interface
• Scanner Access Now Easy (SANE) – a public-domain interface to raster-image scanner-hardware
• I/O Kit – an open-source framework from Apple for developing macOS device drivers
• Installable File System (IFS) – a filesystem API for IBM OS/2 and Microsoft Windows NT
• Open. WhatIs.com. TechTarget. Retrieved 19 March 2018.
• ^EMC Education Services (2010). Information Storage and Management: Storing, Managing, and Protecting Digital Information. John Wiley & Sons.
• ^Burke, Timothy (1995). Writing device drivers: tutorial and reference. Digital Press.
• ^'MAKEDEV — Linux Command — Unix Command'. Linux.about.com. 2009-09-11. Retrieved 2009-09-17.
• ^'User-mode vs. Kernel-mode Drivers'. Microsoft. 2003-03-01. Retrieved 2008-03-04.
• ^'Introduction to the User-Mode Driver Framework (UMDF)'. Microsoft. 2006-10-10. Retrieved 2008-03-04.
• ^Deborah Morley (2009). Understanding Computers 2009: Today and Tomorrow. Cengage Learning.
• ^Computer Peripherals and Interfaces. Technical Publications Pune. January 2008. pp. 5–8. ISBN8184314744. Retrieved 2016-05-03.
• ^'What are Device Drivers and why do we need them?'. drivers.com. April 17, 2015. Retrieved March 19, 2018.
• ^'CCISS'. SourceForge. 2010. Retrieved 2010-08-11. Drivers for the HP (previously Compaq) Smart Array controllers which provide hardware RAID capability.
• ^Russell, Steve; et al. (2003-10-21). 'Abbreviations and acronyms'. Server Consolidation with the IBM eserver xSeries 440 and VMware ESX Serve. IBM International Technical Support Organization. p. 207. ISBN0-7384-2684-9. Retrieved 2011-08-14.
• ^'US Patent 5969841 - Gigabaud link module with received power detect signal'. PatentStorm LLC. Retrieved 2009-09-08. An improved Gigabaud Link Module (GLM) is provided for performing bi-directional data transfers between a host device and a serial transfer medium.
• ^'Unified Audio Model (Windows CE 5.0)'. msdn.microsoft.com. Retrieved 2016-09-19.
• ^'dxd - dynax driver framework: Main Page'. dxd.dynax.at. Retrieved 2016-09-19.

External links[edit]

The Universal Serial Bus (USB) is technology that allows a person to connect an electronic device to a computer. It is a fast serialbus.

It is mostly used on personal computers. USB is also used on other devices, such as smartphones and video game consoles. USB connects different devices using a standard interface.

Most people use USB for computer mice, keyboards, scanners, printers, digital cameras, and USB flash drives. There are over six billion USB devices around the world.

The standard was made to improve plug and play devices. This means that a device can be plugged into a free socket, and simply work. The computer will notice the device. The computer sometimes installs special software to use the device. The device can be removed after it stops being used. This technology is called 'hot swapping'. 'Hot swapping' means it can be plugged and unplugged while the power is on. The computer does not need to be turned off for people to change the devices.

USB can provide a small amount of power to the attached device through the USB cord. Devices that only need a little power can get it from the bus, and do not need a separate electric power plug. That allows gadgets like USB battery chargers, lights, and fans.

As of 2015, USB has mostly replaced several older standards. Those include the parallel port, serial port and SCSI. These old standards are still used for a few jobs where USB cannot replace them.

• 4USB Connectors
• 5How USB is done

Brief history[change | change source]

The first version of the Universal Serial Bus was created in 1995. This new technology became an instant success. Since the introduction of USB, people that make electronic devices thought about how it could be used in the future. Today, USB connects a computer or other devices like laptops and MP3 players to peripheral devices.

The bus was introduced by seven companies which represent the leaders in the industry of information technology: Compaq, IBM, Intel, Microsoft, NEC, Northern Telecom, and Digital Equipment Corporation (DEC).

Several years earlier, adopters and developers of USB held a meeting called Plugfest at a special hotel in California to test their devices. They selected a hotel that included rooms for sleeping and for testing. The meeting lasted three days. During the meeting, the representatives of about 50 companies connected their USB devices to one general host system.

The logo of the USB device also has its own history. The USB logo was in development for several months.

• 1994 - Seven companies united to begin the development of USB.
• 1995 - 340 companies formed the USB Implementation Forum.
• 1996 - More than five hundred USB products were already developing around the world.
• 1997 - USB Implementation Forum became richer with 60 more companies.
• 1998 - USB becomes the most popular technology on the market of electronics.
• 2000 - The introduction of USB 2.0. Today it represents the most widely used USB device.
• 2005 - USB becomes wireless.
• 2008 - USB 3.0 is introduced. It is over 10 times faster than USB 2.0.
• 2013 - USB 3.1 is introduced. It is about twice as fast as USB 3.0.
• 2015 - USB Type-C is introduced. It is a reversible connector, which means that you can plug it in both ways.

Different standards[change | change source]

Currently, five different USB standards are used: USB 1.0, USB 1.1, USB 2.0, USB 3.0 and USB 3.1. USB 3.1 was released in 2016 and doubled the speed of 3.0. It optionally uses a different connector called USB Type-C, which is reversible (meaning you can plug it in both ways).^[1] USB 1.0 is now rarely used.

USB offers five different transfer speeds: 1.5 MBit per second (called low speed), 12 MBit per second (Full Speed), 480 MBit/second (Hi Speed), 5Gbit per second (called super speed), and 10 Gbit/s (“super speed+“). Hi speed is only available in USB 2.0 and later, and Super speed is only available in USB 3.0. These speeds are raw bit rates (in Million bits per second). The actual data rate is usually lower due to protocol overhead.

In order to use the hi speed transfer rate, the USB controller and the connected device both need to support it. USB is backwards compatible. Faster and slower USB devices and controllers can be connected together, but they will run at the slower speed.

USB Hubs[change | change source]

Almost all computers sold today have USB ports, and most of them support USB 2.0 or later. The number of ports they have is usually limited, though. Between two and six ports are common. USB allows connecting USB hubs to add more USB ports.

The hubs themselves are also compliant to one of the USB standards. Devices connected to a USB 1.1 hub will only go as fast as USB 1.1 rates. Devices connected to a later controller can use different standards.

USB Connectors[change | change source]

USB was designed to be easy to use. The engineers learned from other connectors before they designed USB connectors. There are 3 connectors.

• Type A, commonly used at computer end of cable
  • Micro-A (rare)
• Type B, at peripheral end, rare except for printers
  • Micro-B, at peripheral end, for most smartphones
• Type C, at either end. As of 2017, many new computers, phones and peripherals use it.

Windows Xp Usb Controller Driver

Usability[change | change source]

• It's not possible to plug in a USB A or B connector the wrong way. They can not go in upside down, and it is obvious from the look and kinesthetic feeling, when it goes in properly. Sometimes, however, a user doesn't understand or see how the connector goes, so it might be necessary to try both ways.
• Type C USB connectors can be plugged in both ways. It does not matter which way the connector is plugged in.
• There is no need to push or pull very hard to plug or unplug it. This was in the specification. USB cables and small USB devices are held in place by the gripping force from the receptacle. USB does not need screws, clips, or other fasteners. The force needed to make or break a connection is small. This allows connections to be made in awkward positions or by those with motor disabilities.
• Before the advent of Type C, the connectors enforced the directed topology of a USB network. USB does not support cyclical networks, so the connectors from incompatible USB devices are themselves incompatible. Unlike other communications systems (e.g. RJ-45 cabling) gender-changers were almost never used before the advent of USB-On-The-Go (OTG), making it difficult to create a cyclic USB network.

Durability[change | change source]

• The connectors are designed to be tough. Early connector designs were fragile, with pins or other delicate components which could easily bend or break, even if treated gently. The electrical contacts in a USB connector are protected by a plastic tongue. The entire connecting assembly is usually further protected by an enclosing metal sheath. As a result, USB connectors can safely be handled, inserted, and removed, even by a small child.
• The connector construction always ensures that the external sheath on the plug contacts with its counterpart in the receptacle before the four connectors within are connected. This sheath is typically connected to the system ground, allowing otherwise damaging static charges to be safely discharged by this route (rather than via delicate electronic components). This means of enclosure also means that there is a (moderate) degree of protection from electromagnetic interference afforded to the USB signal while it travels through the mated connector pair (this is the only location when the otherwise twisted data pair must travel a distance in parallel). As well, the power and common connections are made after the system ground but before the data connections. This type of staged make-break timing allows for safe hot-swapping and has been used for connectors in the aerospace industry.
• The newer USB micro receptacles are designed to allow up to 10,000 cycles of insertion and exertion between the receptacle and plug, compared to 500 for the standard USB and Mini-USB receptacle. This is done by adding a locking device and by moving the leaf-spring connector from the jack to the plug, so that the most-stressed part is on the cable side of the connection. This change was made so that the connector on the (relatively inexpensive) cable would bear the most wear instead of the micro-USB device.

Compatibility[change | change source]

• The USB standard specifies relatively big tolerances for compliant USB connectors. This is done to minimize incompatibilities in connectors produced by different vendors (a goal that has been very successfully achieved). Unlike most other connector standards, the USB specification also defines limits to the size of a connecting device in the area around its plug. This was done to prevent a device from blocking adjacent ports due to its size. Compliant devices must either fit within the size restrictions or support a compliant extension cable which does.
• Two-way communication is also possible. Usually cables have only plugs, and hosts and devices have only receptacles: hosts having type-A receptacles and devices type-B. Type-A plugs only join with type-A receptacles, and type-B with type-B. However, an extension to USB called USB On-The-Go allows a single port to act as either a host or a device — chosen by which end of the cable plugs into the socket on the unit. Even after the cable is hooked up and the units are talking, the two units may 'swap' ends under program control. This facility targets units such as PDAs where the USB link might connect to a PC's host port as a device in one instance, yet connect as a host itself to a keyboard and mouse device in another instance.

How USB is done[change | change source]

Dell Driver For Usb Controller

A USB system has an asymmetric design. It is made of a host, several downstream USB ports, and multiple peripheral devices connected in a star topology. Additional USB hubs may be included in the tiers, allowing branching into a tree structure with up to five tier levels.

A USB host can have multiple host controllers. Each host controller provides one or more USB ports. Up to 127 devices, including the hub devices, may be connected to a single host controller.

USB devices are linked in series through hubs. There is always one hub known as the root hub. The root hub is built into to the host controller. There are special hubs, called 'sharing hubs'. These allow multiple computers to access the same peripheral devices. They work by switching the access between PCs, either manually or automatically. They are popular in small-office environments. In network terms, they converge rather than diverge branches.

A physical USB device can have several logical sub-devices that are referred to as device functions. A single device may provide several functions, for example, a webcam (video device function) with a built-in microphone (audio device function).

USB device communication is based on pipes (logical channels). Pipes are connections from the host controller to a logical entity on the device named an endpoint. The term endpoint is occasionally used to incorrectly refer to the pipe. A USB device can have up to 32 active pipes, 16 into the host controller and 16 out of the controller.

Each endpoint can transfer data in one direction only, either into or out of the device, so each pipe is uni-directional. Endpoints are grouped into interfaces and each interface is associated with a single device function. An exception to this is endpoint zero, which is used for device configuration and which is not associated with any interface.

When a USB device is first connected to a USB host, the USB device enumeration process is started. The enumeration starts by sending a reset signal to the USB device. The speed of the USB device is determined during the reset signaling. After reset, the USB device's information is read by the host, then the device is assigned a unique 7-bit address. If the device is supported by the host, the device drivers needed for communicating with the device are loaded and the device is set to a configured state. If the USB host is restarted, the enumeration process is repeated for all connected devices.

The host controller polls the bus for traffic, usually in a round-robin fashion, so no USB device can transfer any data on the bus without an explicit request from the host controller.

Host controllers[change | change source]

The computer hardware that contains the host controller and the root hub has an interface for the programmer. It is called Host Controller Device (HCD) and is defined by the hardware implementer.

For USB 1.0 and 1.1, there were two different HCD implementations, Open Host Controller Interface (OHCI) and Universal Host Controller Interface (UHCI). OHCI was developed by Compaq, Microsoft and National Semiconductor, UHCI by Intel.

Usb Controller Driver Windows 7

VIA Technologies licensed the UHCI standard from Intel; all other chipset implementers use OHCI. UHCI relies more on software. This means UHCI is slightly more processor-intensive than OHCI but easier and cheaper to make. Because there were two different implementations, operating system vendors and hardware vendors needed to develop and test on both of them. This increased cost.

The USB specification does not specify any HCD interfaces and is not concerned with them. In other words, USB defines the format of data transfer through the port, but not the system by which the USB hardware communicates with the computer it sits in.

During the design phase of USB 2.0, the USB-IF insisted that there was only one implementation. The USB 2.0 HCD implementation is called the Enhanced Host Controller Interface (EHCI). Only EHCI can support hi-speed (480 Mbit/s) transfers. Most of PCI-based EHCI controllers have other HCD implementations called 'companion host controller' to support Full Speed (12 Mbit/s) and may be used for any device that claims to be a member of a certain class. An operating system is supposed to implement all device classes, so it can provide generic drivers for any USB device. Device classes are decided upon by the Device Working Group of the USB Implementers Forum.

USB device classes[change | change source]

What Is A Usb Controller Driver Needed For Windows 7

Device classes include:^[2]

What Is A Usb Controller Driver Needed For Driver

What Is A Usb Controller Driver Needed For Pc

Note class 0: Use class information in the Interface Descriptors. This base class is defined to be used in Device Descriptors to indicate that class information should be determined from the Interface Descriptors in the device.

Related pages[change | change source]

References[change | change source]

1. ↑Meet the new reversible USB Cnet
2. ↑USB Class Codes at USB.org