使用stm32f030使用四线制spi来驱动ssd1315的代码并给出使用页面寻址方式实现显示字符串

以下是使用STM32F030的四线制SPI驱动SSD1315的代码。假设SPI1已经初始化完成，且SPI1的NSS引脚已经配置成了GPIO输出模式并且初始化为高电平。这里使用的是STM32F030C8T6的板子，SSD1315的CS引脚接在了PA4引脚上。

#include "stm32f0xx.h"

#define SSD1315_CS_LOW()    GPIOA->BRR = GPIO_Pin_4
#define SSD1315_CS_HIGH()   GPIOA->BSRR = GPIO_Pin_4

void SSD1315_WriteCommand(uint8_t cmd)
{
    SSD1315_CS_LOW();
    SPI_I2S_SendData16(SPI1, (uint16_t)(cmd & 0x00FF));
    while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
    SSD1315_CS_HIGH();
}

void SSD1315_WriteData(uint8_t data)
{
    SSD1315_CS_LOW();
    SPI_I2S_SendData16(SPI1, (uint16_t)(data & 0x00FF) | 0x0100);
    while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
    SSD1315_CS_HIGH();
}

void SSD1315_Init()
{
    // 初始化SPI1，这里省略了具体代码
    // ...

    // 初始化SSD1315
    SSD1315_WriteCommand(0xAE); // Set Display OFF
    SSD1315_WriteCommand(0xD5); // Set Display Clock Divide Ratio / Oscillator Frequency
    SSD1315_WriteCommand(0xA0); // Set Segment Re-map
    SSD1315_WriteCommand(0xC8); // Set COM Output Scan Direction
    SSD1315_WriteCommand(0xDA); // Set COM Pins Hardware Configuration
    SSD1315_WriteCommand(0x02); // Alternative COM Pin Configuration, Disable COM Left/Right Re-map
    SSD1315_WriteCommand(0x81); // Set Contrast Control
    SSD1315_WriteCommand(0x7F); // 0x00~0xFF
    SSD1315_WriteCommand(0xA4); // Entire Display ON
    SSD1315_WriteCommand(0xA6); // Set Normal Display
    SSD1315_WriteCommand(0xD3); // Set Display Offset
    SSD1315_WriteCommand(0x00); // 0x00~0x3F
    SSD1315_WriteCommand(0x40); // Set Display Start Line
    SSD1315_WriteCommand(0xAF); // Set Display ON

    // 清屏
    for (int i = 0; i < 8; i++)
    {
        SSD1315_WriteCommand(0xB0 + i); // Set Page Address
        SSD1315_WriteCommand(0x00);     // Set Lower Column Address
        SSD1315_WriteCommand(0x10);     // Set Higher Column Address
        for (int j = 0; j < 128; j++)
        {
            SSD1315_WriteData(0x00);
        }
    }
}

void SSD1315_ShowString(uint8_t x, uint8_t y, char *str)
{
    SSD1315_WriteCommand(0xB0 + y); // Set Page Address
    SSD1315_WriteCommand(0x00 + (x & 0x0F)); // Set Lower Column Address
    SSD1315_WriteCommand(0x10 + ((x >> 4) & 0x0F)); // Set Higher Column Address

    while (*str != '\0')
    {
        for (int i = 0; i < 6; i++)
        {
            SSD1315_WriteData(Font6x8[(*str - ' ') * 6 + i]);
        }
        str++;
    }
}

在上面的代码中，`SSD1315_WriteCommand()`和`SSD1315_WriteData()`用于向SSD1315写入命令和数据。`SSD1315_Init()`函数用于初始化SSD1315并且清屏，`SSD1315_ShowString()`函数用于在指定位置显示字符串。这里使用了一个6x8的ASCII字符库`Font6x8`，需要自己定义。

其中，`SSD1315_ShowString()`函数使用了页面寻址方式。SSD1315的显示区域被分为8个页面，每个页面有128个列，每列有8个像素点。寻址时需要设置页地址、列地址的高位和低位。`SSD1315_ShowString()`函数中的`x`和`y`参数表示要显示字符串的左上角在屏幕上的位置，其中`x`的范围是0到127，`y`的范围是0到7。