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


ʾḶ́
1ϵϵͳʱΪRCH72MHz
2ʼSPIGPIOţ
3SPI1ʼΪģʽͨΪPCLK/322.25MHZ
   ͨģʽΪģʽ2λΪMSBģʽʹSPI
4SPI1ΪNSSƬѡӻʼѯʽ
   շ̣շɺNSSƬѡźţͨš