ʾʹõԴ
SPI1_NSS    ------  PA15
SPI1_SCK    ------  PB3
SPI1_MISO   ------  PB4
SPI1_MOSI   ------  PB5


ʾḶ́
1ϵϵͳʱΪRCH72MHz;
2ʼSPI1GPIOţ
3SPI1ʼΪģʽͨΪPCLK/322.25MHZͨģʽΪģʽ2;
   λΪMSBģʽ
4SPI1ΪNSSƬѡźţʼDMAʽͽݣշɺNSSƬѡźţͨš
