PA2  - Alternate output  (USART2 TX)
PA3  - Normal input      (USART2 RX)
PA9  - Alternate output  (USART1 TX)
PA10 - Normal input      (USART1 RX)
PA11 - 				     (USB D-)
PA12 - 				     (USB D+)

PB10 - Push Pull output  (USB switch).
PC13    - Push Pull output  (LED)