XHRA-2HPA No USB Activity Topic is solved

[DHembree]

I am implementing the XHRA-2HPA on a proof-of-concept board. For simplicity, I am using the part in strap-mode (no flash config). I have downloaded and installed the driver (XMOS-Stereo-USB-Audio-Class2-Driver-_Hi-Res-Audio_1.0) on a Windows & PC. SELF_PWR is enabled. When I power the board on, or connect the USB, the PC does not recognize the device, nor can I see any activity on the USB bus. I monitored the SPI_CLK pin and can see a number of pulses generated upon reset, so this confirms the device is at least active in some way. All power and ground pins are correct - checked and re-checked. I'm not sure what I am missing. Any help is appreciated.

Dan

[mon2]

Dan,

have not worked with this specific controller but fairly sure an external pre-programmed QSPI (quad spi) flash memory device must be mapped onto this device to operate correctly. The flash will hold the respective firmware for the USB and audio functions.

On this topic, there are some threads discussing methods to flash a pre-soldered QSPI flash device for production including the use of holding the XMOS device at a reset so that the QSPI port pins will tri-state and then you can assert external logic levels to inject the required firmware.

[DHembree]

It's my understanding that basic functionality is available with this particular device without any external program. This is per the data sheet. Upon boot the device looks for configuration information via Qflash, but if none exists it has a default configuration. I see the initial activity on the SPI clock pin as it looks for flash memory, but then it ceases. I don't see any signal activity on the USB pins.

[Ross]

The part requires the flash to initialise properly.

[DHembree]

Ross, can you refer me to the part of the data sheet that states this?

Are you saying that the flash must be present even if it's empty?

Thanks,
Dan

[mon2]

https://www.xmos.com/support/boards?pro ... nent=19657

https://www.xmos.com/support/boards?product=18340

https://www.xcore.com/forum/viewtopic.php?f=7&t=3388

https://www.xcore.com/forum/viewtopic.php?f=7&t=4390

https://www.xmos.com/download/private/x ... 1.2%29.pdf

section 8:

[DHembree]

This is from the platform manual, not the device data sheet. I am implementing the XHRA-2HPA on a self-designed board.

[Ross]

Heya,

Section 6 mentions:

The XHRA-2HPA needs to be provided with a clock and a Quad SPI flash

6.3 states:

A Quad SPI flash memory with a minimum size of 1 MByte must be attached to the device.

The QSPI flash memory should store the device firmware binary and the optional configuration information. Further information on the XHRA-2HPA firmware binary is available at http://www.xmos.com/products/audio/xcore-audio-hi-res-2.

Hope that clears things up.

Cheers
Ross

[DHembree]

This is very confusing!



XHRA-2HPA Datasheet (page 22)

Appendices
A Configuration
The system is configured through one of two mechanisms:

- a limited number of straps or

- the flash that contains configuration information.

Flash configuration overwrites all strap options.
.
.
.
.
.

If no configuration straps are used, and there is no information in flash, then the
device will configure to:

- Bus-powered (ie, VBUS should power 1V and 3V3)
- Up to 192 KHz sample rate only.
- USB Audio class 2.0.
- HID inputs disabled.

This is a useful default for applications like a headphone amplifier.

[Ross]

If no configuration straps are used, and there is no information in flash...

The intention of this statement is "no configuration information" rather than no data at all.