用Python验证PSoC Creator生成的cyacd每行的checksum

只看该作者 · 2024-2-22 15:02

本帖最后由 IFX_Lingling 于 2024-2-22 15:20 编辑

在Cypress的 .cyacd 文件中，每一行的校验和(checksum)是通过一个简单的过程计算出来的。校验和的计算过程如下：
1. 首先，把每一行的所有字节值加在一起，包括记录类型、数据长度、地址和数据本身。
2. 然后，取这个和的最后一个字节。也就是说，如果你的和是0x1234，那么你需要取的是0x34。
3. 接下来，取这个字节的二进制反码。二进制反码是通过把所有的1变为0，所有的0变为1得到的。例如，如果你的字节是10110011，那么它的二进制反码就是01001100。
4. 最后，把这个二进制反码加1。这就是你的校验和。
For example：

复制

04C811931100

:00004D008000100020912600006D2800006D28000080B500AF024B83F3088800F0F1F8C0460010002080B500AF0D4B0D4A12688021C9020A431A60202000F09EF9094B0A4A1A600A4B802212061A60054B802212031A60074B00221A60C046BD4680BDC04600010B4004010B400600008008010B400C020B4080B582B000AF72B6FB1D002228

最后的0x28是checksum的值，下面是验证这个值的步骤：
1：第一步把这一行的数据变成16进制数组的形式：
data = [0x00,0x00,0x4D,0x00,0x80,0x00,0x10,0x00,0x20,0x91,0x26,0x00,0x00,0x6D,0x28,0x00,0x00,0x6D,0x28,0x00,0x00,0x80,0xB5,0x00,0xAF,0x02,0x4B,0x83,0xF3,0x08,0x88,0x00,0xF0,0xF1,0xF8,0xC0,0x46,0x00,0x10,0x00,0x20,0x80,0xB5,0x00,0xAF,0x0D,0x4B,0x0D,0x4A,0x12,0x68,0x80,0x21,0xC9,0x02,0x0A,0x43,0x1A,0x60,0x20,0x20,0x00,0xF0,0x9E,0xF9,0x09,0x4B,0x0A,0x4A,0x1A,0x60,0x0A,0x4B,0x80,0x22,0x12,0x06,0x1A,0x60,0x05,0x4B,0x80,0x22,0x12,0x03,0x1A,0x60,0x07,0x4B,0x00,0x22,0x1A,0x60,0xC0,0x46,0xBD,0x46,0x80,0xBD,0xC0,0x46,0x00,0x01,0x0B,0x40,0x04,0x01,0x0B,0x40,0x06,0x00,0x00,0x80,0x08,0x01,0x0B,0x40,0x0C,0x02,0x0B,0x40,0x80,0xB5,0x82,0xB0,0x00,0xAF,0x72,0xB6,0xFB,0x1D,0x00,0x22]
2：
在python3.11里面运行下面这段代码的输出是0x28。

复制

def calculate_checksum(array):

    sum = 0

    for b in array:

        sum += b

    sum = sum & 0xFF

    checksum = ((~sum + 1) & 0xFF)

    return checksum



# 创建一个字节数组

data = [0x00,0x00,0x4D,0x00,0x80,0x00,0x10,0x00,0x20,0x91,0x26,0x00,0x00,0x6D,0x28,0x00,0x00,0x6D,0x28,0x00,0x00,0x80,0xB5,0x00,0xAF,0x02,0x4B,0x83,0xF3,0x08,0x88,0x00,0xF0,0xF1,0xF8,0xC0,0x46,0x00,0x10,0x00,0x20,0x80,0xB5,0x00,0xAF,0x0D,0x4B,0x0D,0x4A,0x12,0x68,0x80,0x21,0xC9,0x02,0x0A,0x43,0x1A,0x60,0x20,0x20,0x00,0xF0,0x9E,0xF9,0x09,0x4B,0x0A,0x4A,0x1A,0x60,0x0A,0x4B,0x80,0x22,0x12,0x06,0x1A,0x60,0x05,0x4B,0x80,0x22,0x12,0x03,0x1A,0x60,0x07,0x4B,0x00,0x22,0x1A,0x60,0xC0,0x46,0xBD,0x46,0x80,0xBD,0xC0,0x46,0x00,0x01,0x0B,0x40,0x04,0x01,0x0B,0x40,0x06,0x00,0x00,0x80,0x08,0x01,0x0B,0x40,0x0C,0x02,0x0B,0x40,0x80,0xB5,0x82,0xB0,0x00,0xAF,0x72,0xB6,0xFB,0x1D,0x00,0x22]



# 计算校验和

checksum = calculate_checksum(data)



# 打印校验和

print('The checksum is: ', hex(checksum))

Python3.11运行结果：

复制

>>> def calculate_checksum(array):

...     sum = 0

...     for b in array:

...         sum += b

...     sum = sum & 0xFF

...     checksum = ((~sum + 1) & 0xFF)

...     return checksum

...

>>> # 创建一个字节数组

>>> data = [0x00,0x00,0x4D,0x00,0x80,0x00,0x10,0x00,0x20,0x91,0x26,0x00,0x00,0x6D,0x28,0x00,0x00,0x6D,0x28,0x00,0x00,0x80,0xB5,0x00,0xAF,0x02,0x4B,0x83,0xF3,0x08,0x88,0x00,0xF0,0xF1,0xF8,0xC0,0x46,0x00,0x10,0x00,0x20,0x80,0xB5,0x00,0xAF,0x0D,0x4B,0x0D,0x4A,0x12,0x68,0x80,0x21,0xC9,0x02,0x0A,0x43,0x1A,0x60,0x20,0x20,0x00,0xF0,0x9E,0xF9,0x09,0x4B,0x0A,0x4A,0x1A,0x60,0x0A,0x4B,0x80,0x22,0x12,0x06,0x1A,0x60,0x05,0x4B,0x80,0x22,0x12,0x03,0x1A,0x60,0x07,0x4B,0x00,0x22,0x1A,0x60,0xC0,0x46,0xBD,0x46,0x80,0xBD,0xC0,0x46,0x00,0x01,0x0B,0x40,0x04,0x01,0x0B,0x40,0x06,0x00,0x00,0x80,0x08,0x01,0x0B,0x40,0x0C,0x02,0x0B,0x40,0x80,0xB5,0x82,0xB0,0x00,0xAF,0x72,0xB6,0xFB,0x1D,0x00,0x22]

>>>

>>> # 计算校验和

>>> checksum = calculate_checksum(data)

>>>

>>> # 打印校验和

>>> print('The checksum is: ', hex(checksum))

The checksum is:  0x28

>>>