How to inform a Model/TableView that some data changed?

[Petruza]

Ok I'll try to explain better:

I have a char array that's the underlying data structure.
I've subclassed QAbstractTableModel to act as the model.
I've added a Table view like this:



I have a timer that increments the underlying data, in its [0,0] position.
Right now, when I select a cell, or interact in some way with the table, then the cell's value is updated, because the table view somehow calls the model's data() method.
What I want to achieve is on each timer event, twice per second, the view updates the cell's values on the screen.
So please tell me what object should be the sender, and what signal of it, and what object should be the receiver, and what slot of it.
Or if I can achieve this with just a method call, instead of signals.

Edit:
I tried emitting layoutChanged() from the model, which works ok.
But I'm setting a timer with 0 msec timout and all I get is the signal emitted no more than 30 times per second, I need something faster.

Can't I just inform the view to update exactly the cell I know has changed?
I tried with the signal QAbstractItemModel::dataChanged, but I can't emit it from a QAbstractTableModel subclass, although it should inherit QAbstractItemModel's members, so what, aren't signals inherited?