USB 1.1 without a Hub


pmprog

DNF (Did Not Finish)
Joined
Apr 25, 2011
Messages
4,150
In one of ED's posts (I think in the Pyra boards) he mentions that RISC/OS supported USB 1.1 devices without a HUB.

I posted a question in there asking if this change could be made to SuperZaxxon, but there was no reply.

Does anybody know how to change the port to work with USB 1.1, or would that require an actual update to SuperZaxxon?

(My question post is here)
 
Last edited by a moderator:
I think it was Kernel Specific.

A normal Switch to put the Mode to 1.1 for next Restart would be difficult to realize.

When its possible to Switch to Usb1.1 would it be great for many Devices exept Usb Sticks or Usb Harddisks.

Maybe someone can realize to switch the Kernel to a Usb 1.1 Option.

A switching Option would be cool ;)
 
In one of ED's posts (I think in the Pyra boards) he mentions that RISC/OS supported USB 1.1 devices without a HUB.
I find this information rather hard to believe. A configuration using anything else than EHCI with host port (not OTG) is mentioned nowhere on TI wiki. Also extesive googling didn't bring any results.
 
I remember that ED said that the port does indeed support USB 1.1, but not both at the same time - ED decided to use USB 2.0, RISC OS went for USB 1.1.
 
It's not software controllable, so not possible. It can only work in LS/FS (aka 1.1) mode with a different PHY chip (tiny BGA part close to where connector is soldered).
 
According to ED it is possible but needs a reboot:

Das koennten wir schon immer.
Der USB-Controller kann entweder USB 1.1 oder 2.0 (OHCI oder EHCI)
Das wird im Kernel konfiguriert.

Leider kann er nicht im Betrieb umschalten (ist ein Bug im Controller).

Im Pandora OS laeuft er im 2.0-Modus, hier offensichtlich im 1.1-Modus (bei USB Sticks ist er dann schweinelangsam und pure USB2.0-Geraete gehen gar nicht).
http://forum.gp2x.de/viewtopic.php?f=24&t=15953&p=191720&hilit=risc+USB#p191720

Mistakes, mistakes everywhere. 
 
Last edited by a moderator:
Yep, one thing that happened to be some mistake / misunderstanding, and it haunts you regularly.
 
It's not software controllable, so not possible. It can only work in LS/FS (aka 1.1) mode with a different PHY chip (tiny BGA part close to where connector is soldered).
That's what is written in the big OMAP35xx Tech Ref Manual, Chapter 23. I wasn't sure my understanding was right, so I tried to force OHCI HCD on the port, and it indeed fails to communicate at PHY level (bit stuffing/device not accepting address errors). Or maybe these errors were collateral, as most of the time the the port doesn't detect anything no matter what you plug in.

Topic closed, I guess.

PS. Just to make it clear, the topic is not about OTG port, which indeed supports LS/FS/HS in host mode (and FS/HS in slave mode).
 
Last edited by a moderator:
Back
Top