Chip makers prepare silicon for USB version 2.0

Chip makers prepare silicon for USB version 2.0
By David Lammers and Loring Wirbel, EE Times
August 31, 2000 (5:40 p.m. EST)
URL: http://www.eetimes.com/story/OEG20000831S0021

SAN JOSE, Calif. — The movement toward the 2.0 version of the Universal Serial Bus is picking up steam. At last week's Intel Developer Forum, silicon vendors showed integrated silicon for hosts, hubs and peripherals that support transfer rates of up to 480 Mbits/second for the high-speed standard. That is nearly 40 times faster than the USB 1.1 specification, which tops out at 12 Mbits/s, said Jason Ziller, an Intel Corp. manager who chairs the USB Implementers Forum.

With its higher transfer rates, USB 2.0 is expected to play a key role in multimedia computing, wireless LANs and Internet-access appliances. For example, a USB 2.0 high-speed link could make it much easier to "burn" a CD-R recordable disk with MP3-compressed audio files from a portable audio player, or with video from a digital video camera that supports the USB 2.0 interface, Ziller said. External hard drives are in development that will transfer data at more than 400 Mbytes/s.

Windows NT did not include USB support, but Microsoft Corp. has included the USB 2.0 software stack in its Windows 2000 operating system. That move is expected to foster USB's adoption in the commercial marketplace, just as Windows 98 played a major role in making the original USB interface a success. Also, the Windows Millennium OS, due out in October and aimed at the consumer market, will support the 2.0 specification.

Intel announced that it has set up a compliance laboratory at its Hillsboro, Ore., facility — the USB 2.0 Peripheral Integration Lab — where peripheral manufacturers will be able to bring equipment for debug and compliance feedback.

Also, Intel will build motherboards based on the Pentium 4 processor that will include discrete USB 2.0 control silicon. Other desktop vendors are expected to offer either built-in support, or add-in boards to the host, as early as the fourth quarter.

Ready to roll

And "the peripheral vendors are not waiting," Ziller said . "They are planning to come out with peripherals, such as printers, external storage, videoconference cameras and scanners that will be marked 'USB 2.0 ready.' "

The new version is expected to displace the USB 1.1 specification starting next year, while maintaining compatibility with older USB peripherals. Also, the cables and connectors of the two specs are interchangeable. More information is available at the USB Implementers Forum Web site.

Among the silicon offerings rolling out for USB 2.0 are devices from Lucent Microelectronics, Cypress Semiconductor and Sican Microelectronics. Lucent has consciously chosen to make its 2.0-compliant USS-2000 host controller backward-compatible with USB 1.1. The controller, resident in the server to control multiple device types, complements the USS2X1 physical-layer chips that comply with USB 2.0.

Sujal Shah, director of computer I/O marketing in Lucent's access business unit, said that an interesting overlap in function i s occurring with the 480-Mbit/s USB 2.0, as devices compliant with the new standard overlap in speed and function with IEEE-1394 devices, and are occasionally used in isochronous video appliances. Lucent produces chips for 1394 as well as one controller that handles both USB and 1394, though Shah said he still sees a market segmentation. In his view, video and image-capture devices will use 1394, while printers and Internet appliances rely on USB.

"USB will tend to stay dominant in host-to-peripheral applications, while 1394 will dominate in peer-to-peer applications," Shah said.

The four-channel USS-2000 combines a single 480-Mbit/s USB 2.0 host and four separate 12-Mbit/s USB 1.1 hosts with integrated transceivers. Also on the chip are a PCI interface module, a pipeline cache control module, a list-processor module, a serial interface engine, a PCI power-management module, a memory buffer and a PCI bus arbiter. The device can interface with any 32-bit PCI bus, at either 33 or 66 MHz.

The physic al-layer USS2X1 devices reside on the client side of a USB 2.0 hub. The device can operate in a USB 2.0 or USB 1.1 mode, with appropriate termination provided on-chip for either speed. The chip transmits and detects the chirp patterns required in the high-speed detection sequence of USB 2.0.

Shah said that many OEMs had been asking for four-channel board-level solutions to ease the upgrade to USB 2.0, so Lucent worked with Belkin Components Inc. to develop a four-channel 48-Mbit card called QuadraBus, which Belkin is selling as a transitional product to evolve to the USB 2.0 host and client chips.

Cypress Semiconductor Corp., meanwhile, has announced that its USB 2.0 high-speed peripheral control silicon has passed muster at the Intel compliance lab in Hillsboro. The EZ-USB FX2 single-chip solution integrates a USB 2.0 transceiver, a serial interface engine, an 8051 controller and a programmable interface. Other companies have opted to use an FPGA for the digital portion and a separate analog device for the transceiver function.

Cypress, the largest supplier of USB silicon, expects to see revenues triple to about $100 million this year.

Sican Microelectronics Corp., headquartered in Hannover, Germany, introduced a synthesizable soft core, called the USB 2.0 Function DesignObject, at the Intel Developer Forum. The solution is aimed at a customer-specific ASIC that would support USB 2.0 high-speed functionality in peripherals.