Disable High Speed USB

Steve Deschryver

Expert 1115 points

Other Parts Discussed in Thread: AM3354

On the AM3354 I would like to disable HS support for USB B (2nd) and only support LS and FS.

In the datasheet I found the HSENAB bit in the POWER register on page 1718 (SPRUH73H) would do the job,

but no where else in the datasheet I can find the address (or any other info) of this bit ???

whats the address of this bit or is there a other way to disable HS USB please ?

over 12 years ago

0 Bin Liu over 12 years ago

TI__Guru**** 179451 points

Steve,

In Table 2-1 (Page 156), the start_address of USB1 Core is 0x47401C00, the offset of POWER register is 0x1.

So the address of POWER register is 0x47401C01. It is a 8-bit register.

0 Steve Deschryver over 12 years ago in reply to Bin Liu

Expert 1115 points

Thanks, I will test this tomorrow.

Is there any more information available on this register en fucntion of the bits please ?

0 Bin Liu over 12 years ago in reply to Steve Deschryver

TI__Guru**** 179451 points

Steve,

The documentation for USB Core registers are not publicly available, it requires NDA. But The Linux MUSB driver has the definition for most (if not all) bits of the Core registers, and how those bits have been used in the USB drivers.

0 Steve Deschryver over 12 years ago in reply to Bin Liu

Expert 1115 points

Hi,

I've got it working now for both USB ports, will have to add a check to the many routines to only restrict USB1.

Only have the Win compact 7 BSP available, not the Linux code, but your help was enough to get me started.

regards,

Steve

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Disable High Speed USB