从选择引脚模式

定义
#define	LL_SPI_NSS_SOFT   (SPI_CR1_SSM)
#define	LL_SPI_NSS_HARD_INPUT   0x00000000U
#define	LL_SPI_NSS_HARD_OUTPUT   (((uint32_t)SPI_CR2_SSOE << 16U))

---

定义文档

#define LL_SPI_NSS_HARD_INPUT   0x00000000U

NSS引脚用于输入。仅用于主设备模式

Definition at line 232 of file stm32g4xx_ll_spi.h.

Referenced by LL_SPI_StructInit().

#define LL_SPI_NSS_HARD_OUTPUT   (((uint32_t)SPI_CR2_SSOE << 16U))

NSS引脚用于输出。仅用作从设备模式的片选

Definition at line 233 of file stm32g4xx_ll_spi.h.

#define LL_SPI_NSS_SOFT   (SPI_CR1_SSM)

NSS在内部管理。不使用NSS引脚，将其释放

Definition at line 231 of file stm32g4xx_ll_spi.h.