ATSAM*70 USB stack experiences

[hans]

I'm looking to use the ATSAM*70N series parts (probably S is all I need) for a future project, where I need a USB2.0 HS connection combined with a high clock peripheral system. I'll be building a streaming data application at 10MB/s tops, in particular the internal (or external) ADC could be of use. This MCU ticked those boxes.

I've been bitten in the past by USB stacks supplied by vendors before, and I wonder if anyone else here has experiences with the supplied USB stack on these ATSAM parts.  On the PC side I'll probably be using libusb. How stand-alone is the stack to use (apart from dependency on CMSIS)? For example I know that Microchip originally had Harmony for the PIC32 series, has this blessing or plague transcended down to Atmel parts so far?

[ataradov]

You have a choice between Atmel Start and ASF. Neither stack is very standalone, they both will depend on a lot of stuff, and ripping them out of the framework is not easy.

On a plus side, the hardware is not that hard to work with, so depending on your requirements you can just roll your own.

[hans]

Thanks for the pointers Alex. I also saw your replies here and took a short look at the Atmel Start and ASF.

ASF was a huge download, and couldn't really find my way through it.
Atmel Start looked surprisingly pretty bare bones in terms of the USBHS example, but need to take another look to see how much configuration options there are. In this case I download a USB HID example project.

I haven't taken a look at the RTLs of many USB peripherals yet and similarities among other series. If you say they are quite simple , I might as well attempt to adapt my previously used (and slightly refactored..) USB device stack to the Atmel driver.
Is there any "magic" needed to get the HS functionality working over FS?

[ataradov]

Is there any "magic" needed to get the HS functionality working over FS?

Nope, just setting one bit in a configuration register. HS and FS only differ at the very begging of the enumeration stage, which is taken care of by the hardware. Well, HS stack also has to include some test code, which is used when you do the certification, if you ever want to do it.

I had some test code for USB on SAM E70. It was pretty messy, but I will try to find it, clean it up a bit and publish it. I was getting good performance on capturing external 8-bit stream of data and sending that to PC.