2 wire or 5 wire xmos links?

[gerrykurz]

How does the compile decide whether to implement an interface or a channel as a 2 wire or a 5 wire link? Is there a way of telling the compiler to use a fast link for a particular interface or channel?

[pstnotpd]

You specify the link type in the XN file

See the XN specification

[gerrykurz]

I think the xn file you are referring to is for external bonded out links to other parts. I am asking about internal links between cores and tiles on a single part.

[pstnotpd]

Why would you want to switch a single device to 2w (slow) mode? I believe the whole point of slow mode is to stabilize chip interconnect.

I think I read somewhere that intra device links are always 5w

[segher]

An important reason for using 2w links is that it uses much
fewer pins.

At (rom) boot time all links (including internal links) are used
as 2w links.

The normal XN files for L2 etc. parts use 5w for the internal
links. You want to use those, not write an XN from scratch.