USB 3.0 hub controllers - Page 1
Forum section: electronics / general

author: djlidz08
author_rank: Newbie
timestamp: March 31, 2014, 02:32:57 pm
content: I'm new to forums here on EEV blog, but I've been following the channel for almost a year now and I figured I'd put the blog to some real use. I would like to start by getting some insight on some USB 3.0 hub controllers to see which one's best, so far the only one's I've seen on the market are the VLI 800 series (812 in specific) and Texas Instruments. Can anyone shed some light on this for me, I'm a bit lost as to which one works more efficiently, or if there's another one which would be better or best. Thanks

author: poorchava
author_rank: Super Contributor
timestamp: March 31, 2014, 02:37:25 pm
content: I guess that depends: do you want to buy one or design one?

author: marshallh
author_rank: Unknown
timestamp: March 31, 2014, 04:04:10 pm
content: TI one for sure.I am not impressed with the VLI host controller I have used so far. Fails many USBIF compliance tests with flying colors! (Then again, they all do)

author: djlidz08
author_rank: Newbie
timestamp: April 01, 2014, 11:32:35 pm
content: poorchava: I'm looking to buy then design onemarshallh: I'll do more research on the TI controllers, hopefully I won't have to resort to VLIthanks guys

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 03, 2014, 02:44:40 pm
content: This is somewhat related, but only remotely; currently, i'm looking for a USB 3 hub with multiple USB 2 outputs.Eg, the hub plugs into a USB 3 port (5gbit), and then, provides a number (6+) USB 2 post at full speed (480mbit).From my searching, I cannot find such a device, they all seem to just act as a standard USB 2 hub, eg, plug into the USB3 port but operate at usb 2 speeds and provide shared bandwidth across hub ports.

author: Rigby
author_rank: Super Contributor
timestamp: April 03, 2014, 03:03:04 pm
content: Quote from: peter.mitchell on April 03, 2014, 02:44:40 pmThat's more than just a hub, and that's why you're probably not going to be able to find one. Such a device would need to act as a USB3 device and act as a USBhostfor the devices you plug in. I don't know of such a device.Maybe just a USB3 hub would do the business for you. If you plug in USB2 devices into a USB3 hub, does the whole hub bump down to USB2, or just the one port?

author: free_electron
author_rank: Super Contributor
timestamp: April 03, 2014, 05:04:10 pm
content: look at cypress

author: miguelvp
author_rank: Super Contributor
timestamp: April 03, 2014, 05:09:17 pm
content: Quote from: peter.mitchell on April 03, 2014, 02:44:40 pmWill this do?http://www.cypress.com/?docID=47970CYUSB3326 2 USB3.0 2SS, 2 USB2.0CYUSB3328 4 SS and 4 USB2.0

author: miguelvp
author_rank: Super Contributor
timestamp: April 03, 2014, 06:20:05 pm
content: I guess I was too busy typing and looking for things to notice that free_electron already suggested it.Edit: Ignore the FX3 stuff, it's for peripherals not a hub.but leaving the links in case you need the peripheral side of things.But adding some more info regarding the FX3 (the link before is for the HX3)FX3 dev kit info on this post:https://www.eevblog.com/forum/microcontrollers/cypress-fx3-development-kit/msg408770/#msg408770And the nuvation demo software that I refer to on that link would be here:http://www.nuvation.com/electronic-design-services/usb-3-fx3But the FX3 might be old and the HX3 might have better specs, didn't look at the details.

author: abyrvalg
author_rank: Frequent Contributor
timestamp: April 03, 2014, 08:40:37 pm
content: CY FX3/HX3 are NOT hubs

author: andersm
author_rank: Super Contributor
timestamp: April 03, 2014, 09:24:02 pm
content: Microchip recently launched the USB553xB series of hub controllers. No idea if they're any good.

author: miguelvp
author_rank: Super Contributor
timestamp: April 03, 2014, 10:23:05 pm
content: Quote from: abyrvalg on April 03, 2014, 08:40:37 pmYou are right on the FX3 my bad.but the HX3 is a hub according to cypresshttp://www.cypress.com/?id=167http://www.cypress.com/hx3/

author: Zeta
author_rank: Contributor
timestamp: April 04, 2014, 02:06:31 am
content: Cypress has always been in the top in the USB host/hub/periferal controller market.Cypress HX3 is what you are looking for. fullUSB uplink and several usb2 ports

author: abyrvalg
author_rank: Frequent Contributor
timestamp: April 04, 2014, 08:15:12 am
content: miguelvp, sorry, now it's my mistake, I knew what is FX3 but didn't checked that newer HX3Regarding peter.mitchell's question: I'm curious too, how a 3.0 hub will behave with both 3.0 and 2.0 devices plugged in? Older 2.0 hubs had a transaction translator for 1.1 devices, but HX3 block diagram shows no such things for 3.0-2.0, it looks more like 3.0 devices will go 3.0 path over SSRX/SSTX upstream pairs while 2.0 devices will use legacy D+/D- pair in parallel with that - is it possible?

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 04, 2014, 09:00:22 am
content: Quote from: Zeta on April 04, 2014, 02:06:31 amUnfortunately no, it isn't.I may need to explain myself more clearly;I am looking for a chip/solution that does the following;USB 3 transceiver to provide high bandwidth connectivity between the host and the "glue logic""glue logic" that takes the USB 3 PIPE connection, processes it, provides an interface for a number of USB 2 controllersA number of USB 2 controllers that interface with the glue logic to provide several full bandwidth USB 2 ports.Why am I looking for such a thing?USB 3 provides a flexible, high bandwidth, common, external interface. USB 2 provides a flexible, medium bandwidth, common, cheap, external interface.As the bandwidth provided by USB 3 is an order of magnitude higher than that of USB 2, it makes sense to use it to provide the bandwidth to downstream USB 2 ports.Basically any USB 3+USB 2 hub application would prove useful for this design/configuration, Eg, you have an external USB 2 hard drive and an external USB 2 flash drive, both can saturate the bandwidth of a USB 2 connection. If you wish to transfer a file from one device to the other, you will be limited to the bandwidth of the USB hub/controller they are connected to, divided between the two devices, in this case, since they can both saturate a USB 2 connection, their bandwidth is halved. This is significant, and this is directly using the device on the USB host controller (on a root hub ofc), let along using the devices on an external USB hub.Why the HX3 and similar products don't work;They provide two separate interfaces and two separate hubs. Essentially, they have both a USB 2 and a USB 3 connection going to them, which is then sent to it's respective hub. Logic then decides based on what is plugged into the port as to which hub the port is connected to. This means although there is a 5gbit connection between the "chip", the bandwidth available for USB 2 is only 480mbit, which is shared amongst the USB 2 ports.

author: miguelvp
author_rank: Super Contributor
timestamp: April 04, 2014, 09:41:35 am
content: "All ports support SS (5 Gbps), and are backward-compatible with HS (480 Mbps), FS (12 Mbps), and LS (1.5 Mbps)"Doesn't that mean that each of the (4 ports on the CYUSB3328) are backward compatible with HS (USB 2.0)?I guess that's not the 6 ports you are looking for but the CYUSB3326 can do 2 USB 3.0, 2 SS AND 2 USB 2.0. wouldn't that do the trick?Or is it because it's using 2 share link ports they are really physically not interconnected?Then the CYUSB3314 could do 4 USB 3.0 backwards compatible with 2.0 but that's not 6 I guess.Then again, could you daisy chain 4 HX3's into one? just wondering.

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 04, 2014, 10:33:18 am
content: Quote from: miguelvp on April 04, 2014, 09:41:35 amYou're not understanding.Maybe this picture will help;

author: marshallh
author_rank: Unknown
timestamp: April 07, 2014, 02:18:07 am
content: I have extensive experience with USB. What you're wanting isn't possible. SorryThe only possibility is to emulate a device and then re-host all other devices. Which would be a major PITA, involve months of dev time, and depend on your top host stack working with it.

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 14, 2014, 02:20:21 pm
content: Quote from: marshallh on April 07, 2014, 02:18:07 amI wasn't looking to design the chip itself, nor was i intending to implement it in an fpga etc, i was looking for a chip available from a large semiconductor manufacturer that had this functionality, and thus the only things need doing would be trivial by comparison.I was under the impression that because it is possible to cost effectively produce cross protocol + cross phy usb controllers, eg; usb to ethernet bridge, usb to sata bridge, usb to pata, usb to i2c, usb to spi etc, that in the same fashion, it would also be possible to produce a cost effective usb 3.0 to usb 2.0 bridge, even if it were just to provide USBI guess no one has bothered or is interested yet.

author: abyrvalg
author_rank: Frequent Contributor
timestamp: April 14, 2014, 02:49:59 pm
content: USB 2.0 has transaction translator (FS/LS to HS conversion) in hub specification, so it is in every 2.0 hub. USB 3.0 doesn't have this feature specified (it says "USB 2.0 hub is a separate device, we don't discuss it in this document at all"), so there are no such hubs yet. There are chances that some "creative" manufacturer will make something like that beyond the specs in the future, but time also works against it - with wider 3.0 adoption there will be less interest in 2.0 performance.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 14, 2014, 06:03:19 pm
content: Pretty much every modern PC has multiple USB 2 controllers anyways. For example, the DX79SI has 4 USB 2 controllers.

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 15, 2014, 08:25:08 am
content: Quote from: NiHaoMike on April 14, 2014, 06:03:19 pmexcept for sayyy... laptops, where external media is most used.

author: amyk
author_rank: Super Contributor
timestamp: April 15, 2014, 01:08:54 pm
content: Maybe some MCU with a USB 3.0devicecontroller and multiple 2.0hostcontrollers could do what you want, but then it would be bandwidth-limited.It could probably be done in an FPGA if you wanted to.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 17, 2014, 05:30:11 pm
content: Quote from: peter.mitchell on April 15, 2014, 08:25:08 amAll the modern ones I have come across have at least 2 USB 2 controllers. The only modern chipsets I know of that only have one USB 2 controller are low power SoCs, but they're not fast enough to really take advantage of the extra bandwidth anyways.