USB PHY recommendations

I've used the SMSC / Microchip USB3320 in a few designs.

I have seen problems with the ULPI itself if the bus is allowed to float by the master, which can actually inject spurious register writes into the PHY. This can happen if the ULPI is on multipurpose pins on a microcontroller or FPGA that need to be programmed to be in ULPI mode.

BTW, I found I couldn't use the TI TUSB1210 part in my designs due to power supply rail sequencing requirements between the 3.3V and 1.8V rail.

There's a diode between VBAT and VDDIO. This wasn't mentioned on the TI datasheet, despite being a feature of the silicon!

This may or may not be a problem for your design, depending on your power supply.

Regards, Allan

Many thanks for your insight.

This is connected to a FPGA, where I have access and have control of all the relevant pins.

The power sequencing hasn't been a problem, perhaps I'm lucky? Just applying reset to the PHY makes it come back to life!

Have you looked at the Cypress device?

I sort of discounted them as they weren't showing in stock with DigiKey.

Have you used them? Are they reliable?

We have used the USB3315 extensively in our products, which are used with a huge number of hosts and devices. We have never had a problem with this chip.

The USB3315 was made by SMSC (which was bought up by Microchip Tech). This particular chip is now hard to get hold of. I assume that other chips from that series (such as the one Allan mentioned above) will be just as reliable.

Regards, Alex

Many thanks for your endorsement.

Microchip claim the USB3315 is still in production.

Hi Mike,

I just spoke to a colleague, and he did mention there was one problem with the chip: When operating in Full Speed there are some features that don't w ork quite correctly. Many Full Speed applications will work fine though, an d operating with High Speed or Low Speed is bullet proof (as far as USB goe s). It hasn't bothered us though as we only use Full Speed in specific circ umstances.

Regards, Alex

Many thanks for your trouble.

I only intend to use High Speed though could drop down to Full Speed.

Do you know what were these "features" that don't work correctly.

This project is currently on hold but will restart shortly!

Hello I appreciate your guidance in advance!

I want to implement a high speed USB 2.0 host controller on FPGA for an image processing application. There are none free USB 2.0 host high speed IPs and commercial IPs are very expensive for me. I want to read some files and processing them.

Now, I have a Altera FPGA and USB3300 ULPI PHY.

I also find document and read that.(ULPI interface. UTMI+ Low Pin Interface (ULPI) Specification REV 1.1 oct 20 2004) . In this document only discuss about handshaking an transmit packet. I want understand how can I read some cluster from flash memory in USB mass storage device.

What kind of other protocols and interfaces are required for "read file from usb mass storage"?

The ULPI document is only helpful on the interface, and even then it has some shortcomings.

You will need the USB 2.0 document and the document associated with the class of device you want to talk to.

I've written just an introduction that is still work in progress, but I hope might be of some use to you.

It also provides links to the files you're likely to need.

As you say USB 2.0 High Speed IP is not easily available though there are a few helpful articles.

An alternative is to use SD cards that use the much simpler SPI interface.