I have a CP2615 which is configured to keep both MCLK and LRCLK active at all times - but this does not happen under all circumstances.
There appears to be a state where the audio driver shuts down the part and the clocks stop. I can trigger this every time using Windows Media Player; when the audio track stops the clocks continue but if the program is closed then they stop.
The reason for wanting them active is that the product I'm designing also has an analogue audio input and I need the clock source to be able to handle this.
Is there a way to stop this behaviour? The datasheet is not very clear on this feature.
So this is being caused by the low power (idle) mode on the CP2615. My question thus becomes: is there any way to disable low power mode?
I feel the settings in Simplicity, along with the datasheet are very misleading - the MCLK and LRCLK always active options suggest just that, but they do nothing of the sort.
Please can a SiLabs employee respond to this.
The clocks remain on as long as the device remains in high power mode. But when audio stops streaming, usually the device goes back into low power mode. We are not as clear as we could be in the documentation about how this works. From your question, it seems like there needs to be a configurable option to prevent entering low power mode, thus leaving the clocks running at the expense of a little power. We will add this to the feature request list for possible future updates.
In the meantime, there is one possible workaround but may not be feasible for you. The device has an IO protocol that is carried over bulk endpoints. If there is an IO session active then it remains in high power mode. But this means you would need an application program running on your host computer that opens some endpoints on the device and leaves them open.
Thank you for the clarification - that was what I suspected.
My solution was to fit a separate oscillator which is used when analogue audio mode is required.