Can't Program Flash

[shaw]

We are working on a project based on the XCORE.AI multi-channel audio board. We have designed new hardware, keeping the critical XMOS connections the same as they were on the AI Eval board. Board has successfully been powered up and runs our XMOS firmware. Basic audio operation is functional and we are able to Debug(xgdb/XTAG4) and run software, on our board.

Our issue is that we cannot program FLASH. We have tried both the XFLASH command (using XTC tools 15.2.1 Command Prompt, XTAG4) and the Thesycon DFU tool. Both approaches appear to Fail in the same way. They both start with a Chip Select enable and a Fast Read Quad IO (EBh). They both return a series of expected 0xFF (Flash has never been programmed). The Chip select goes high (disabled.) The Program(s) hangs before a 2nd Chip select is enabled.

We have kept the XMOS connections to USB and external FLASH the same as on the AI evaluation board. We are using the same FLASH device as was used on AI evaluation board. Any insight on what might be wrong or where to focus our debug/troubleshooting would be appreciated.

Thanks


Note: We were able to successfully FLASH the AI evaluation board multiple times.

[mmar]

XN file is same or changed ? Show cmd and return error...

[Joe]

What console output do you get from xflash?

Should be easy to see the problem if you posted a schematic, assuming it's not a soldering issue.

Try and find some signs of life with:
xflash --target-file=XCORE-AI-MCAUDIO-600.xn --spi-read-id 0x9F

replace XN with your XN.

You should get:
Response to SPI ID command on tile[0]: 0xef, 0x40, 0x16, 0x0.

Cheers,
Joe

[shaw]

mmar,, Joe,

I've attached XN file and Response to Read ID command. I'm taking a look at how to put together a snip of schematic.

[shaw]

attached Schematic:

[Joe]

Hi,

I can't see all the IO of the xmos device but my guess is you don't have the xmos link wired up to the XTAG4 or there is a problem with it.

The link is defined in your XN as connecting to XL0:

<Links>
<Link Encoding="2wire" Delays="5clk" Flags="XSCOPE">
<LinkEndpoint NodeId="0" Link="XL0"/>
<LinkEndpoint NodeId="2" Chanend="1"/>
</Link>
</Links>

If this link isn't present they you should remove it from the XN.

Try xflash with the --force-jtag option and it should work.

Cheers,
Joe

P.S. Not related but from your schematic the 680R resistor is in the wrong position in your oscillator - need to be in line with the XOUT pin.

[shaw]

Joe,

Thank-you very much, that did it. Also, thanks for catching the resistor placement.

Best,