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USB Products


smxUSBH™

smxUSBH is a simple USB host stack for embedded systems. It is written in C, and can be ported to any hardware platform. smxUSBH is optimized for SMX®, but can be ported to other RTOSs or run stand alone. It is modularized so that only what is needed will be linked into the final application.

• Class Driver Layer provides USB device support such as mouse, keyboard, hub, printer, mass storage, and serial.
• USB Driver Layer, or Core, provides the common USB device framework functionality.
• Host Controller Driver Layer provides host controller driver functionality and contains root hub support.
• Porting Layer provides service functions related to the hardware, OS, and compiler.

• EHCI
• OHCI
• UHCI
• Atmel AT91
• Cirrus Logic EP93xx
• Freescale MCF525x, 532x/7x
• Maxim MAX3421
• NXP/Philips ISP1160/1
• NXP/Philips ISP1362
• NXP/Philips ISP1760/1
• NXP/Philips LPC2xxx, 3xxx
• NXP/Sharp LH7A4xx

Class Drivers

smxUSBH has extensive class driver support, further enabling us to provide an out-of-the-box solution to your USB requirements.

Audio

Allows you to connect a USB headset, speaker, or microphone. Many functions are provided for playback and record. See the smxUSBH User’s Guide for the API.

CDC ACM   (Modem)

Allows you to connect most USB modems and some mobile phones if they follow the USB CDC ACM specification. It allows you to use a modem to connect to the Internet or sync and exchange data with a mobile phone.

su_CDCACMOpen(id)
su_CDCACMClose(id)
su_CDCACMInserted(id)
su_CDCACMRead(id, pdata, len)
su_CDCACMWrite(id, pdata, len)
su_CDCACMGetLineState(port, pstate)
su_CDCACMGetLineCoding(port, rate, parity, databits, stopbits)
su_CDCACMSetLineState(port, state)
su_CDCACMSetLineBreak(port)
su_CDCACMSetCommFeature(port)
su_CDCACMGetCommFeature(port)
su_CDCACMRegisterStateChangeNotify()

Ethernet

Allows you to connect to USB to Ethernet adapters that use the ASIX 88772 chip. A TCP/IP stack such as smxNS is also required.

su_NetInserted(iID)
su_NetOpen(iID)
su_NetClose(iID)
su_NetWriteData(iID, pData,len)
su_NetGetNodeID(port, pData)
su_NetRegisterPortNotify(port, handler)

HID (Generic)

This is the basis to support human interface devices such as a joystick.

su_HIDInserted()
su_HIDSetCallback(handler)

Keyboard

Allows you to connect a USB keyboard.

su_KbdInit()
su_KbdInserted()
su_KbdRelease()
su_KbdSetCallback(handler)

Mass Storage

Allows you to connect a USB flash disk (thumb drive), USB hard disk, USB card reader, or USB floppy drive. It also supports devices with multiple logical units, such as some USB card readers and thumb drives. smxFS is already interfaced to this driver. It is very easy to interface another file system to it, if desired.

su_MStorIO(buf_ptr, first_sector, num_sectors, reading)
su_MStorMaxLUN()
su_MStorMediaChanged()
su_MStorMediaInserted()
su_MStorMediaProtected()
su_MStorMediaRemoved()
su_MStorSectorNum()
su_MStorSectorSize()

Mouse

Allows you to connect a USB mouse.

su_MouseInit()
su_MouseInserted()
su_MouseRelease()
su_MouseSetCallback(handler)

Printer

Allows you to connect a USB printer and print to it or read data from it. You need to implement the Print Control Language for your specific printer.

su_PrnID(pdata, len)
su_PrnInit()
su_PrnInserted()
su_PrnRead(pdata, len)
su_PrnRelease()
su_PrnReset()
su_PrnStatus()
su_PrnWrite(pdata, len)

Serial

Allows you to connect any serial device that Windows XP or 2000 can support without a custom driver, such as a Windows Mobile 5 device. Unfortunately, most serial adapters do require installation of a custom driver. Additional code must be developed to support such an adapter, which could require significant effort. We have already created a driver for USB to serial converters that use the FTDI FT232 chip. Please see the smxUSBH User’s Guide for details, and discuss your requirements with us.

Windows
su_SerialOpen(id)
su_SerialClose(id)
su_SerialInserted(id)
su_SerialRead(id, pdata, len)
su_SerialWrite(id, pdata, len)
su_SerialGetLineState(port, pstate)
su_SerialGetLineCoding(port, rate, parity, databits, stopbits)

FT232
su_FTDIOpen(id)
su_FTDIClose(id)
su_FTDIInserted(id)
su_FTDIRead(id, pdata, len)
su_FTDIWrite(id, pdata, len)
su_FTDISetModemCtrl (port, data)
su_FTDISetFlowCtrl (port, data)
su_FTDISetLineCoding(port, rate, parity, databits, stopbits)
su_FTDIGetModemStatus (port)
su_FTDIGetStatus (port)
su_FTDISetEventChar(id, data)
su_FTDISetErrorChar(id, data)
su_FTDISetLatencyTimer(id, ms)
su_FTDIGetLatencyTimer(id)

Writing New Drivers

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

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

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

Porting

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

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

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

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


16-Bit Addressing Support

smxUSBH 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 smxUSBH.

Real Mode and DOS Support

There is a need for legacy x86 systems to add USB support, especially for flash disks. Because of this, smxUSBH supports OHCI and UHCI in real mode. OHCI uses memory mapped I/O, and the PCI BIOS assigns a high address near the top of the 4GB memory space, which is not accessible in real mode. We provide two solutions for this. A 386 or better may be required. See the OHCI section of the smxUSBH User's Guide for details. UHCI uses x86 I/O space for access to UHCI registers, but a 386 or better is required for the 32-bit I/O instructions.

Testing

Unlike USB Device, there is no protocol compliance testing for software, for USB Host. Instead, we test the host stack and class drivers using multiple devices of each class, as listed in Appendix C of the smxUSBH User’s Guide.

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

The following table shows raw transfer speed from and to a USB flash disk. 20MB total transfers are done 4KB at a time.

The following table shows smxFS read/write performance for the same USB flash disk. Total file size is 20MB with 4KB transferred, at a time.

The following table shows raw data transfer speed between EHCI and LACIE USB 2.0 40GB hard disk

The following table shows serial read/write performance. The device driver reads/writes 256 bytes of data at a time from/to the USB serial device (not connected to a real RS232 device).

Notes:
1. The hardware environment for this testing is: Celeron 300MHz CPU; 32MB 100M SDRAM; PC motherboard; Host Controller connects to System by 33MHz PCI bus.
2. Flash Disk is Lexar JumpDrive USB 2.0 512MB
3. CPU speed, SDRAM speed and size, and External Memory Bus speed will affect the performance.



smxUSB Product Overview (PDF)

For More Information

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