topic ULPI to HSIC Bridge in MPC5xxx

ULPI to HSIC Bridge

nextsteve — Tue, 21 Feb 2017 06:08:55 GMT

Hi,

I found this app note relating to trends in USB in automotive:

http://cache.freescale.com/files/training/doc/ftf/2014/FTF-AUT-F0335.pdf

In particular, I found this quote:

There are HSIC-to-ULPI transceivers that provide HSIC functionality to standard USB 2.0 devices.

Is the HSIC to ULPI transceiver a real component? If so could someone give me a part number?

Thanks,

Steve

Re: ULPI to HSIC Bridge

lydia_ziegler — Tue, 21 Feb 2017 20:43:13 GMT

Hi Steve,

HSIC does not act like a ‘normal’ USB chip, it is High Speed only. So, it probably does not make sense to convert from HSIC to ULPI. If you want to add more HSIC connections, an HSIC hub would probably be better because the hub adds flow/speed control downstream. Note that HSIC is really only meant to be a high speed connection between devices on the same PCB so be sure to keep the traces short to avoid noise issues.

I suspect that the actual desire is to add additional USB ports to the design. If that is the case, why not look at a USB hub to add the extra ports?

If there is a concern with regards to bandwidth, I would recommend using the i.MX6D/Q Plus. The i.MX6Dual/Quad Plus has a bit more streamlined internal routing of the DDR which will aid in overall throughput.

Hope this helps,

Lydia

Re: ULPI to HSIC Bridge

nextsteve — Tue, 21 Feb 2017 21:10:06 GMT

Hi Lydia thanks for responding. You are definitely the most helpful IMX6 support person I've encountered so I'm glad you're online.

The actual desire is to convert the USB ULPI interface on my MPC5xxx to HSIC so I can directly interface it to one of the HSIC USB Hosts on my IMX6 instead of using a ULPI USB transceiver IC to the IMX6 OTG.

The bullet point I found on that automotive USB presentation sounded exactly like what I needed so I was wondering if that was an actual component I could buy and use or if it is a theoretical thing that is possible. I see a different company sells ULPI-HSIC as an HDL IP block but I want an actual component.

Thanks,

Steve

Re: ULPI to HSIC Bridge

lydia_ziegler — Wed, 22 Feb 2017 14:12:55 GMT

Thanks for the extra info, that makes sense. Have you checked with Microchip? They would probably be your best bet for an HSIC -> ULPI converter chip since they have acquired SMSC.

Re: ULPI to HSIC Bridge

nextsteve — Wed, 22 Feb 2017 14:38:46 GMT

I did check with Microchip and they don't have a part like that either. So it must only exist as an IP block for now.

Thanks,

Steve

Re: ULPI to HSIC Bridge

lydia_ziegler — Wed, 22 Feb 2017 15:50:06 GMT

Do you have a SPI port available? You can get fairly high speeds to do inter processor communication. Maybe that would be an option to consider.

Thanks,

Lydia

Re: ULPI to HSIC Bridge

nextsteve — Wed, 22 Feb 2017 16:24:28 GMT

Preference of my software programmers to use USB over SPI due to Linux driver support.

USB is a bad interchip embedded interface so that's why I'm exploring HSIC.

Thanks,

Steve