5GHz bandwidth/channel width - what are the supported values? - 20,40, 80 MHz etc?

Hi,
I am not seeing any info about bandwidth/channel width with 5GHz in Ameba-D SDK.

What channel widths are supported? I can’t clearly see this in the documentation.
in the context of Ameba-D SDK do I need to set bandwidth explicitly or is bandwidth negotiated automatically with the AP on the specific channel?

Thanks,
Ivan