xHRA-2HPA Empty Flash

[JJS3]

If an xHRA-2HPA chip is booted for the first time with an empty flash memory attached does this render the xHRA inoperable? Does it replace the internal flash with empty bytes? Also, why is exactly 1kOhm necessary for the SPI CS_N pull-up on the xHRA?

[henk]

Hi JJS3,

It will try and boot and fail with a CRC check I would guess. It will not write into flash.

The pull up is required to make sure that CS is not asserted during reset.

Cheers,
Henk

[JJS3]

Thanks Henk, Which windows driver should I use for the stock xHRA? I am having trouble seeing the xHRA on the USB port of my Windows 7 computer, I have checked schematics, power supplies are coming up. I even added a longer 200ms delay on the RST_N line (stock delay is about 5us) and the xHRA is still not coming up on the USB port. Any advice would be appreciated.

[henk]

Hi,

You will need the Thesycon driver; see Section 12 of the datasheet.

It should be easier to see it on a Mac or Linux machine - lsusb -v on the latter or AudioMidi setup on the former.

Cheers,
Henk

[JJS3]

Interesting, so the XMOS driver will not work. I have a custom XMOS driver but assume I will need the flash to change PID to use this. I will try the evaluation Thesycon then.

[henk]

Hi,

I am not sure what the xmos driver is; it may be one and the same thing as the thesycon driver?

Cheers,
Henk

[Ross]

You have an allocated PID from XMOS and associated driver?

[JJS3]

Yes we do but I just want to get the stock chip running to prove out design. Then we will program the flash with our PID