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USB Products


smxUSBD™

• Function Driver Layer provides USB functions to application such as mass storage, mouse, and serial.
• Device Core Layer provides the common USB device framework.
• Device Controller Driver Layer provides the interface to the selected USB device controller.
• Porting Layer provides service functions related to the hardware, OS, and compiler.

Function Drivers

The following sections describe each function driver and its API. The USB host is a Windows, Macintosh, Linux system, etc., except for RNDIS, which supports Windows only.

Audio

The Audio function driver makes your device look like a sound card to the USB host. You can include a speaker and/or microphone in this audio device so you can playback and/or record sound. You can also integrate a MIDI port into your device so it can accept MIDI data. There is no need to install any driver or .inf file in Windows to support this device but you may need to implement the sound device driver yourself, according to your system hardware and software environment.

sud_AudioIsConnected(port)
sud_AudioSendAudioData(port, pData, iLen)
sud_AudioGetAudioData(port, pData, iLen)
sud_AudioGetCurSpkSettings(port, pSettings)
sud_AudioGetCurMicSettings(port, *pSettings)
sud_AudioSendMIDIData(port, pData, iLen)
sud_AudioGetMIDIData(port, pData, iLen)
sud_AudioRegisterNotify(port, handler)
sud_AudioPackMIDIEvent(port, pData, pEvent)
sud_AudioUnpackMIDIEvent(port, pData, pEvent)

Mass Storage

The Mass Storage function driver makes your device look like a removable disk to the USB host. You can copy files to and from it.

sud_MSRegisterDisk(pdiskop, lun)

Mouse (Included)

The Mouse function driver makes your device look like an HID mouse to the USB host. It moves the mouse cursor on your PC.

sud_MouseInput(key, x, y, wheel)

Remote NDIS  (Ethernet over USB)

The Remote NDIS function driver makes your device look like a Network Adapter to a Windows USB host. The host can communicate with this device via Ethernet data packets. Normally you need a TCP/IP stack on your device and use the APIs provide by this function driver to emulate an Ethernet device and add it to your network stack. This device has been integrated with smxNS, our TCP/IP stack. Then the Windows host and your device can communicate with each other by TCP/IP with a USB cable instead of an Ethernet cable. One use of RNDIS is to allow configuring a device from the web browser on a Windows PC communicating with a web server on your device. This is especially useful if your processor has only a USB device controller and no Ethernet controller on chip.

sud_RNDISIsPortConnected(port)
sud_RNDISWriteDataPort(port, pBuf, len)
sud_RNDISRegisterPortNotify(port, handler)
sud_RNDISSetEthernetAddr(port MACaddr)

Serial

The Serial function driver makes your device look like one or more COM ports to a Windows USB host. You can use standard Win32 functions to communicate with the device, just like if it were connected to a real RS232 port. For the multi-port option, we provide a custom Windows driver, since the built-in Windows driver supports only one port.

sud_SerialIsPort Connected(port)
sud_SerialWriteData(port, pBuf, len)
sud_SerialDataLen(port)
sud_SerialReadData(port, pBuf, len)
sud_SerialSetLineState(port, iState)
sud_SerialGetLineState(port, piState)
sud_SerialGetLineCoding(port, pdwDTERate, pbParityType, pbDataBits, pbStopBits)
sud_SerialRegisterPortNotify(port, handler)


Composite Devices

smxUSBD allows creating a composite device. Such a device has multiple interfaces that are active at the same time using a single controller chip. For example, a composite device might combine serial and mass storage. See the smxUSBD User's Guide for more discussion of this.


Writing New Drivers

Contact us first to make sure we are not already working on a driver you need.

smxUSBD provides a function driver template and a section in the manual to help you write a new function driver, if needed.

smxUSBD also provides a USB device controller driver template and a section in the manual, to help you write a new driver in case it does not support your USB device controller.
 

Porting

Due to its extensive processor support, little or no porting is necessary when smxUSBD is used with SMX. However, smxUSBD is designed to work with other RTOSs and to run standalone.

The hardware porting layer consists of two files, udhdw.h and udhdw.c These files contain definitions, macros, and functions to port smxUSBD to a new processor. In addition, if the USB device controller is not among those already supported, a new driver will need to be written.

smxUSBD was developed for use with SMX, but it can be ported to any RTOS. The RTOS porting layer consists of two files, udosport.h and udosport.c. These files contain definitions, macros, and functions to port to a new RTOS.

smxUBSD works best in multitasking environment. However, it can also be ported to a non-multitasking stand-alone environment.


16-Bit Addressing Support

smxUSBD supports processors that can only do 16-bit memory addressing  (not byte addressing) such as the TI TMS320C55xx DSPs. These processors are difficult to support for typical communication protocols because of byte data and byte fields in standard protocol data structures. This support is enabled by a configuration option in smxUSBD.


Testing

We test smxUSBD with USBCheck Version 5.1 on a Windows PC to verify that it passes the Chapter 9 USB compliance tests for full speed and high speed.

  
Code Size

Code size can vary greatly depending upon the processor, compiler, and optimization level.

All RAM used by smxUSBD for data is pre-allocated from the heap during initialization. Following is a table of RAM usage:

Performance

Mass Storage
The following table shows mass storage performance using a RAM disk in the device.

Remote NDIS
The following table shows Ethernet over USB performance for the indicated packet size.

Serial
The following table shows the transfer rate for sending and receiving serial data for different application packet sizes.

Notes

1. Full speed
2. High speed

For More Information

• Access the manual.
• Try a free evaluation kit.