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Alternate Function Input on STM32F4

Question asked by Luke on Sep 22, 2012
Latest reply on Oct 11, 2012 by Luke
I'm familiar with using alternate function inputs on the STM32F1 series; the associated GPIO pin is set as an input (CNFx[1:0], MODEx[1:0] bits), AFIO clock is enabled, and the AFIO->MAPR register is set appropriately.

I'm confused how to do the same on STM32F4.  Reading the reference manual (RM0009), table 14 seems to indicate alternate function is always output, either OD or PP, with/without PU/PD.  In the timer input capture example distributed with the STM32F4 peripheral library, the input pin is put into output PP mode.

I find this a bit confusing -- can anybody clarify the use of alternate function inputs on the STM32F4xx series?