记录一次芯片的地址计算

地址介绍#

前几天刚发了一篇ltc2497的六层板绘制过程,这两天准备写它的驱动,奈何芯片比较小众只能自己写(练习一下)

先看他的地址列表

// #define LTC2497_I2C_ADDRESS 0x14    //  Low       Low       Low
// #define LTC2497_I2C_ADDRESS 0x16    //  Low       Low       High
// #define LTC2497_I2C_ADDRESS 0x15    //  Low       Low       Float
// #define LTC2497_I2C_ADDRESS 0x26    //  Low       High      Low
// #define LTC2497_I2C_ADDRESS 0x34    //  Low       High      High
// #define LTC2497_I2C_ADDRESS 0x27    //  Low       High      Float
// #define LTC2497_I2C_ADDRESS 0x17    //  Low       Float     Low
// #define LTC2497_I2C_ADDRESS 0x25    //  Low       Float     High
// #define LTC2497_I2C_ADDRESS 0x24    //  Low       Float     Float
// #define LTC2497_I2C_ADDRESS 0x56    //  High      Low       Low
// #define LTC2497_I2C_ADDRESS 0x64    //  High      Low       High
// #define LTC2497_I2C_ADDRESS 0x57    //  High      Low       Float
// #define LTC2497_I2C_ADDRESS 0x74    //  High      High      Low
// #define LTC2497_I2C_ADDRESS 0x76    //  High      High      High
// #define LTC2497_I2C_ADDRESS 0x75    //  High      High      Float
// #define LTC2497_I2C_ADDRESS 0x65    //  High      Float     Low
// #define LTC2497_I2C_ADDRESS 0x67    //  High      Float     High
// #define LTC2497_I2C_ADDRESS 0x66    //  High      Float     Float
// #define LTC2497_I2C_ADDRESS 0x35    //  Float     Low       Low
// #define LTC2497_I2C_ADDRESS 0x37    //  Float     Low       High
// #define LTC2497_I2C_ADDRESS 0x36    //  Float     Low       Float
// #define LTC2497_I2C_ADDRESS 0x47    //  Float     High      Low
// #define LTC2497_I2C_ADDRESS 0x55    //  Float     High      High
// #define LTC2497_I2C_ADDRESS 0x54    //  Float     High      Float
// #define LTC2497_I2C_ADDRESS 0x44    //  Float     Float     Low
// #define LTC2497_I2C_ADDRESS 0x46    //  Float     Float     High
// #define LTC2497_I2C_ADDRESS 0x45    //  Float     Float     Float

看起来很复杂,貌似没有规律

地址计算#

刚开始我也没看出来,然后我把它放到万能的excel中排了一下序列,结果如下

(第一排是16进制,缺了 0x 不要介意)

规律如下:

• 第一排的第一个数字,也就是地址前四位依次为1-7
• 第二排都为4-7
• low < float < high

是不是发现了规律

本质上就是三进制转为8进制+4进制再加一个基地址0x14

程序编写验证#

拿clion新建了个工程试一下

void set_ltc2497_adress(uint8_t addr2,uint8_t addr1, uint8_t addr0)
{
    //auto calculate the address
    uint8_t num = 0x00;
    num = addr2*9 + addr1*3 + addr0*1;
    num = ((num/4) << 4)|(num%4);
    num = num + 0x14;
    std::cout << "address: " << "0x" << std::hex << int(num) << std::endl;
    

}

int main()
{
    //输出全部地址
    for (int i = 0; i < 3; i++)
    {
        for (int j = 0; j < 3; j++)
        {
            for (int k = 0; k < 3; k++)
            {
                set_ltc2497_adress(i, j, k);
            }
        }
    }


    system("pause");
    return 0;
	return 0;
}

输出结果如下

address: 0x14
address: 0x15
address: 0x16
address: 0x17
address: 0x24
address: 0x25
address: 0x26
address: 0x27
address: 0x34
address: 0x35
address: 0x36
address: 0x37
address: 0x44
address: 0x45
address: 0x46
address: 0x47
address: 0x54
address: 0x55
address: 0x56
address: 0x57
address: 0x64
address: 0x65
address: 0x66
address: 0x67
address: 0x74
address: 0x75
address: 0x76

至此,结束