请教一下关于STM32的GPIO复用功能如何选择？

leavic · 发表于 2011-7-2 14:59:06

有个问题一直没明白，
USART2的CTS,RTS,TX,RX分别位于PA0~3上面，
而TIM2的CH1~CH3也分别位于PA0~3上面，

而复用功能选择寄存器里面，关于这两个功能的复用配置是这样的：

Bits 9:8 TIM2_REMAP[1:0]: TIM2 remapping
These bits are set and cleared by software. They control the mapping of TIM2 channels 1 to
4 and external trigger (ETR) on the GPIO ports.
00: No remap (CH1/ETR/PA0, CH2/PA1, CH3/PA2, CH4/PA3)

=================================================
Bit 3 USART2_REMAP: USART2 remapping
This bit is set and cleared by software. It controls the mapping of USART2 CTS, RTS,CK,TX
and RX alternate functions on the GPIO ports.
0: No remap (CTS/PA0, RTS/PA1, TX/PA2, RX/PA3, CK/PA4)
=================================================

复位后这几位默认都是0，那么假如我同时开启了USART2和TIM2的始终以及AFIO的时钟，我到底会启动那个外设呢？是USART2还是TIM2，这个要如何选择？