Re: Confused about synchronous communications

On a sunny day (Thu, 20 Sep 2007 22:28:37 GMT) it happened "Jon Slaughter"
<Jon_Slaughter@xxxxxxxxxxx> wrote in
<puCIi.8205$JD.5493@xxxxxxxxxxxxxxxxxxxxxxxxxx>:


But then this has a problem of the data changing towards the end of the
clock.

So, I guess my actual question is, when is it required for the data to be
valid?

Depends on the system.
Some systems data is clocked in on the positive edge of the clock,
and in some systems it is clocked in on the negative edge.

And, there could be systems were data is latched when the clock is high,
and systems where data is latched when the clock is low......

In i2c you need to pay especialy attention to start and stop sequences too..

Look at the datasheets is all I can say.
.