OMAP3530 USB HS Question

OMAP35x family does include 3 USB ports that can operate as a host (no hub needed); all three ports operate at either HS or FS mode depending on the selected PHY connection.

In addition, OMAP35x family also includes 1 USB OTG port which can be used as either a peripheral or host port.

I'm looking for throughput numbers on the USB HS OTG for Bulk transfer when it is configured as a Client.  Are those performance numbers available?

As part of SDK install, you should hace a 'docs/OMAP35x/' directory where you will find the Linux LSP User Guide.  This document has performance information for the various peripherals supported, including USB.

I hope this helps.

Hi Juan

Thank you for the quick response.  Unfortunately I do not have the EVM and SDK yet.  I am just trying to get some performance numbers.  If you can post those numbers or direct me where I can get that info that would be great. 

Thanks again,

Gary

Gary,

I do not have this document readily available myself (not available on intranet or extranet either), hence let me try installing SDK next week and I can get you this information.

The numbers as mentioned in PSP1.0.0 docs/OMAP35xx/datasheet are,

1) USB slave DMA read performance (EVM to XP) ~3 MByte per sec

2) USB slave DMA write performance (XP to EVM) ~1 MByte per sec

The performance numbers are captured using the following

·

MMC CARD: SanDisk ULTRAII 1 GB CARD

Default CPU IDLE STATE (C1)

File Format = VFAT, WinXP Host.

Regards,

Ajay

Ajay,

Thank you for saving me the trouble :)

Hey Guys

Thank you for the information.  Those numbers, that performance seems rather slow.  Is this for the USB OTG 2.0 480M channel?  What is the bottleneck there?  Thanks for any incite? 

Yes, these numbers are for USB OTG 2.0. The performace given was measured using MMC card. Using CE-ATA drive will increase performace.

Gadget side storage driver can be modified for further performance improvement.

Hi Ajay

Thanks for the update.  I was hoping that the MMC card was the bottleneck and not the USB pipe. 

MMC card is one of the bottleneck. Using CE-ATA improves performance significantly.USB side

storage driver can also be modified for some more enhancement in performance.

Hi Juan

Can you tell me if the OTG USB port can be used to create a second screen output.  I am trying to set up a second output from a BeagleBoard based build i.e. one LCD output and a mirror image on a projector. 

The preference is to use a USB port, as more projectors tend to have this input.

If this is not possible, could you suggest a better method of creating a projector based output?

Thanks