I'm driving audio out the S/PDIF port. This is working under most other conditions, but when accessing any of the SPI ports the S/PDIF data includes scattered duplicated samples on the left channel, and zeroed samples on the right channel, in sync. Is this a known silicon issue (I didn't see it in the errata), and is there any workaround? SPI is needed to drive several peripherals in this case, while audio should not be interrupted. I2S ports appear to be unaffected (and are needed to drive multiple DACs), and driving other serial controllers (including I2C and UART) does not cause any such glitch, only SPI. The same glitches occur when SPI is driven to a port not connected to the peripherals in question.