CZ75BD/SP01Tactical Half-cocked Operation

In the process of searching for my first handgun and so far I'm tempted by a CZ 75 with decocker. (BD or SP01 Tactical)

I'm still struggling to understand how the SA/DA works in conjunction with the decocker.

From what I've gathered so far, and if someone could attest to the validity of this, I came to the conclusion that DA operation only happens from a half-cocked position of the hammer. See logic below:

DA Operation: load mag -> operate slider (bullet chambered, hammer cocked) -> decocker (hammer halfway cocked) -> fire (double action)

Isn't there a way to bring the hammer completly down without firing a bullet? (asssuming there is a bullet in the chamber)

Please enlighten me! Thanks.