I'm planning to establish an USB connection with a STM32L433. To keep the size of my PCB small, I want to use the LQFP-48 package. By having a look at my former projects using a STM32F407 discovery board, I noticed the pins PA2 and PA3 have to be remaped, as there alternate function includes USART_RX and USART_TX. The following lines are from ARMCM4-STM32F407-DISCOVERY-MEMS:
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* Activates the serial driver 2 using the driver default configuration.
* PA2(TX) and PA3(RX) are routed to USART2.
palSetPadMode(GPIOA, 2, PAL_MODE_ALTERNATE(7));
palSetPadMode(GPIOA, 3, PAL_MODE_ALTERNATE(7));
So my question is, do I need four pins to establish an USB connection (PA2, PA3, PA11, PA12). By remapping PA2 and PA3, I think this two pins can not be used as GPIO pins e.g. as an INPUT ot OUTPUT.
So is there a possebility to establish the USB connection only with PA11 and PA12, as it is shown in the datasheet in appendix A.1? I haven't found an example without the pin remapping. If not, I have to use an other package, because I need this two additional pins.