Feature request: Max/Min ISO/Av/Tv

[janjan]

Hi,
Is it possible to set limits for the max/min values of ISO/Av/Tv?
E.g. say i am in Av mode, and I want to restrict my camera not to use shutter speed lower, or higher than a specific value.
Or I use Av mode and I do not want to go below F5.6 (if i do need to the camera will raise ISO)
On my camera (600D) I can only limit the max ISO to be used but the way to select this is not so convenient.