Hi Folks,
The following customer problem seems to be related to the discusion above.
They have been looking into an issue with the AM3505 High Speed USB channel data download to a USB stick. They are finding high errors for larger size data transfers when we enable the L5 CLK spread spectrum feature. They are using the AM3505 to generate a 60MHz reference clock to drive the USB PHY reference clock. The USB PHY is a USB3320 from SMSC. If they turn off the spread spectrum, there are no data errors. The USB PHY datasheet says it tolerates high levels of jitter on the 60MHz REFCLK input, so the effect of the spread spectrum on the 60MHz itself can’t be the issue.
Are there any known issues on the AM3505 High Speed USB interface when the L5 CLK spread spectrum is enabled?
What are the options if there is an issue with HS USB and L5 CLK when SSC is enabled?
Thanks.