Debug clarification

Technical discussions around xCORE processors (e.g. xcore-200 & xcore.ai).
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Folknology
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Debug clarification

Post by Folknology »

I notice that on the latest versions of the L1-64 reference design (b) and on the latest rev (c) for the XK1 the debug pin connects directly to the SYS connector without a pull up (the older XK1 had one). But the current L2 ref design does include a 4k7 pullup resistor on the debug line. I would just like to clarify which is the correct design for all the L1 series, is it that the L2 is different from a debug POV? Can I safely omit this part with the L1-64 and L1-128?

regards
Al
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segher
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Joined: Sun Jul 11, 2010 1:31 am

Post by segher »

You can leave the global debug pin unconnected if you don't use it; it has an internal
pullup.

If you do use it, it needs to be pulled up externally, since the internal pullup isn't
strong enough to reliably pull it up. Suggested value of the pull-up is 4k7. It seems
this is an oversight in the Xk-1 revC schematics.

I bet you won't use the global debug anyway ;-)