Can I output clock from clock block to 4-bit port?

[xchips]

Hi guys, long time didn't touch XMOS really, I almost forget how to write codes for it...but need to bring it up again.
It's an Audio project, and no more 1-bit port is available, so I want to know if I can output a MCLK clock (49.152MHz for example)
from a clock block to a 4-bit port. From my project, I changed this MCLK clock pin from 1-bit port:

<Port Location="XS1_PORT_1C" Name="PORT_MCLK_OUT"/>

to a 4-bit port:

<Port Location="XS1_PORT_4E" Name="PORT_MCLK_OUT"/>

in XN file, but end up there is no output from any pin of this 4-bit port (By the way, MCLK can work well with 1-bit port).

Thanks a lot for helps.

Best regards.

Jason

[CousinItt]

Hi Jason,

As far as I know only a single-bit port can be configured to output a clock. See XS1 library functions in the xTIMEcomposer user guide and XC Clocked Input and Output documents.

HTH

[akp]

I don't think you'll be able to do the MCLK output. You can clock out a square wave from one pin of your four bit port but its maximum frequency is 1/2 the frequency of the clock you clock it with. So in this case you'd need to clock the 4 bit port from 2xMCLK. I think your best bet would be to clock MCLK from a one bit port and use a four bit port to clock out (or in, for slave) FSYNC (TDM) or LRCLK (I2S). That should be possible with more relaxed timing and the changes should be pretty straightforward.

[xchips]

Hi CousinItt and akp,
thanks a lot for the info.

Best regards
Jason