Clarify that setting SC bit 7 is mandatory on slave to accept a Serial Data Transfer

[avivace]

See #398

@quinnyo @ISSOtm @jbshelton

[quinnyo]

I think this looks good to merge, but there are some other instances of the same issue elsewhere on the page: in the intro and the very last paragraph (under 'Delays and Synchronization'). I don't know if you want to fix them as part of this PR or separately?

[avivace]

I think this looks good to merge, but there are some other instances of the same issue elsewhere on the page: in the intro and the very last paragraph (under 'Delays and Synchronization'). I don't know if you want to fix them as part of this PR or separately?

I'd say let's handle them all in this PR? I just pushed some more changes

[ISSOtm]

I'm now wondering what value is obtained from attempting a transfer when the other GB(C) has not set its bit 7. Could it depend on the last transferred bit?

[avivace]

I'm now wondering what value is obtained from attempting a transfer when the other GB(C) has not set its bit 7. Could it depend on the last transferred bit?

maybe you can open a new 'research' issue regarding this?