Changes

* '''Status A'''

<pre>

bit0-3 [not used] interrupt frequency

* '''Status B'''

<pre>

bit0 1 = take summer time into account

* '''Status C'''

<pre>

bit4 1 = [not used] interrupt has been generated because of time update (see status B, bit4)

* '''Status D'''

<pre>

bit7 0 = battery is nearly empty, please charge or replace