12.4, reading volatile side effect

[dgkeb]

I still don't understand this:
How can I influence the evaluation of the left-hand expression by re-writing the right-hand one?
And also: after re-writing the code the behavior of the && operator should stay the same, means if the left-hand expression is false, the right-hand is not evaluated, is it?

Furthermore I don't understand the reason for this rule: If the first expression is false, the whole expression will be also false anyway. What is the problem? It will be only a problem if the REGISTER must be read every time, e.g. to clear a flag or something.
But I wouldn't put things which have to be done every time in an if-statement.

I have a rule issue with the following loop which waits in a background routine for the end of a transmission. If this doesn't come there is still a timer with which the loop is left after a certain time (to prevent an endless loop). Both are volatile variables and are changed in higher-priority interrupts.

Code:

do {
      } while ((TxFinished == 0) &&          //quit waiting loop when transmission is finished
               (TimeoutTimer != 0));            //or max. waiting time is up

How can I solve this rule?

Thank you and best regards.