STM32 Pipeline to GPIO delay

Hi,

I have to handle some precise delays...

The pipeline on STM32F4 is 3 cycles. GPIO are connected on the AHB bus. 

What is the delay required between a write to a GPIO register (first step of the pipeline) and the effective rising edge of the physical pin ?

(assuming no wait states, no event/interrupt, and only the core is mastering AHB bus.

Thanks