STM32F103和STM32F030的SPI其MISO配置不同之处
在调试STM32F103和STM32F030的SPI时，发现原来的MISO配置不同
STM32F103: /**SPI1 GPIO Configuration PA5 ------> SPI1_SCKPA6 ------> SPI1_MISOPA7 ------> SPI1_MOSI*/GPIO_InitStruct.Pin = GPIO_PIN_5|GPIO_PIN_7;GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);GPIO_InitStruct.Pin = GPIO_PIN_6;GPIO_InitStruct.Mode = GPIO_MODE_INPUT;GPIO_InitStruct.Pull = GPIO_NOPULL;HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
STM32F030:/**SPI1 GPIO Configuration PA5 ------> SPI1_SCKPA6 ------> SPI1_MISOPA7 ------> SPI1_MOSI*/GPIO_InitStruct.Pin = GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7;GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;GPIO_InitStruct.Pull = GPIO_NOPULL;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;GPIO_InitStruct.Alternate = GPIO_AF0_SPI1;HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
其中区别在于, F103的MISO要配置成输入（GPIO_MODE_INPUT), 而F030的要配置成复用(GPIO_MODE_AF_PP)，的确非常奇怪。后来查询RM得知:
F103的配置是：
CNFy[1:0]: Port x configuration bits (y= 0 … 7)
These bits are written by software to configure the corresponding I/O port.
Refer to Table 20: Port bit configuration table.
In input mode (MODE[1:0]=00):
00: Analog mode
01: Floating input (reset state)
10: Input with pull-up / pull-down
11: Reserved
In output mode (MODE[1:0] > 00):
00: General purpose output push-pull
01: General purpose output Open-drain
10: Alternate function output Push-pull
11: Alternate function output Open-drain
Bits 29:28, 25:24,
21:20, 17:16, 13:12,
9:8, 5:4, 1:0
MODEy[1:0]: Port x mode bits (y= 0 … 7)
These bits are written by software to configure the corresponding I/O port.
Refer to Table 20: Port bit configuration table.
00: Input mode (reset state)
01: Output mode, max speed 10 MHz.
10: Output mode, max speed 2 MHz.
11: Output mode, max speed 50 MHz.
F030的定义是：
Bits 2y+1:2y MODERy[1:0]: Port x configuration bits (y = 0…15)
These bits are written by software to configure the I/O mode.
00: Input mode (reset state)
01: General purpose output mode
10: Alternate function mode
11: Analog mode
可以查看，两个片子的识别定义不同所以，配置当然也不同了。
再查询手册的UART RX定义，也有同样的不同。
再用兆易GD32F103替代STM32F103时，发现GD的定义与STM相同，但是MISO必须改为GPIO_MODE_AF_PP才能正常接收，否则 SPI 可以发送，接收错误。 这里表示是 GD 的缺陷，待确认。
参考原文：《[问答] STM32F103和STM32F030的SPI其MISO配置有何不同》
