j2b描述smp协议

参考

用JSON 定义二进制结构j2b.csdn

Zynq上UART/IIC/SPI的27个实验-第24课：PL 逻辑模拟 SPI 从设备

用于连接一些spi外设

{
  "remark": "smp.j2b.json5;MCU 与 FPGA 之间的 SPI 半双工请求-响应协议",
  "agreement": [
    "1. 物理四线 SPI:SCLK/MOSI/MISO/CS,Mode0(CPOL=0,CPHA=0),MSB First",
    "2. 逻辑半双工:MCU 先发请求帧(FPGA 只收),请求发完后 MCU 继续发时钟但 MOSI 发 dummy,FPGA 此时才把响应帧放 MISO",
    "3. 一次事务 CS 全程拉低,事务结束 CS 拉高",
    "4. 请求帧 SOF=0xA5,响应帧 SOF=0x5A,用于区分方向",
    "5. 所有多字节字段大端(网络序),对应 j2b 的 U16/U32",
    "6. 校验方式:全异或,覆盖 [cmd, len, payload],不含 SOF 和 CHECK 自己",
    "7. 帧间 CS 拉高,FPGA 状态机复位回 IDLE",
    "8. MISO 在 FPGA 非发送阶段置高阻",
    "9. 每个 content 对应一个 cmd,请求和响应成对",
    "10. 帧容量 1024 字节,实际长度由 len 字段决定",
    "11. 请求帧总长 = 1 + 1 + 2 + len + 1 = len + 5",
    "12. 响应帧总长 = 1 + 1 + 2 + len + 1 = len + 5",
    "13. payload 直接是 u8[len],靠 len 界定边界",
    "14. len 可以为 0,表示 payload 为空;此时帧总长 = 5 字节",
    "15. len = 0 仍是一个完整响应帧,不等于不响应;所有请求默认都必须响应",
    "16. status 是链路层状态,result 是业务层状态,两者复用同一套 StatusEnum"
  ],
  "schema": {
    "StatusEnum:u8;状态码": {
      "0x00": "OK;成功",
      "0xE1": "ERR_CHECK;异或校验失败",
      "0xE2": "ERR_CMD;未知命令字",
      "0xE3": "ERR_ADDR;地址越界",
      "0xE4": "ERR_LEN;长度非法",
      "0xE5": "ERR_BUSY;FPGA 忙"
    },
    "CmdEnum:u8;命令字": {
      "0x01": "RD_REG;读单个寄存器",
      "0x02": "WR_REG;写单个寄存器",
      "0x03": "RD_BLOCK;读一块数据",
      "0x04": "WR_BLOCK;写一块数据",
      "0x05": "STATUS;读状态字",
      "0x06": "RESET;复位 FPGA"
    },
    "Frame:u8[?]:帧格式": {
      "ReqFrame;请求帧;SOF=0xA5": {
        "sof": "0xA5:u8;帧头固定0xA5,方向 MCU->FPGA",
        "cmd": "CmdEnum:u8;请求命令字",
        "len": ":U16;PAYLOAD 字节数",
        "payload": "u8[len];命令相关字段,见各 content.req",
        "check": "u8;全异或校验,覆盖 [cmd,len,payload],不含 sof 和 check 自己",
        "总长": "len + 5 字节"
      },
      "ResFrame;响应帧;SOF=0x5A": {
        "sof": "0x5A:u8;帧头固定0x5A,方向 FPGA->MCU",
        "status": "StatusEnum:u8;链路层状态",
        "len": ":U16;PAYLOAD 字节数",
        "payload": "u8[len];响应的数据内容value,result,data等",
        "check": "u8;全异或校验,覆盖 [status,len,payload],不含 sof 和 check 自己",
        "总长": "len + 5 字节"
      }
    },
    "ReadReg:Frame;读单个寄存器": {
      "req": {
        "sof": "0xA5:u8",
        "cmd": "0x01:CmdEnum:u8;请求命令字",
        "len": "0x0002:U16;PAYLOAD 字节数",
        "addr": "0:U16;寄存器地址,大端",
        "check": "0:u8;全异或校验,覆盖 [cmd,len,addr]"
      },
      "res": {
        "sof": "0x5A:u8",
        "status": "0x00:StatusEnum;链路层状态",
        "len": "0x0004:U16;PAYLOAD 字节数",
        "value": "0:U32;寄存器值,大端",
        "check": "0:u8;全异或校验,覆盖 [status,len,value]"
      }
    },
    "WriteReg:Frame;写单个寄存器;cmd=0x02;": {
      "req": {
        "sof": "0xA5:u8",
        "cmd": "0x02:CmdEnum:u8;请求命令字",
        "len": "0x0006:U16;PAYLOAD 字节数",
        "addr": "0:U16;寄存器地址",
        "value": "0:U32;写入值",
        "check": "0:u8;全异或校验,覆盖 [cmd,len,addr,value]"
      },
      "res": {
        "sof": "0x5A:u8",
        "status": "0x00:StatusEnum;链路层状态",
        "len": "0x0001:U16;PAYLOAD 字节数",
        "result": "0x00:StatusEnum;业务层结果",
        "check": "0:u8;全异或校验,覆盖 [status,len,result]"
      }
    },
    "ReadBlock:Frame;读一块数据;cmd=0x03": {
      "req": {
        "sof": "0xA5:u8",
        "cmd": "0x03:CmdEnum:u8;请求命令字",
        "len": "0x0004:U16;PAYLOAD 字节数",
        "addr": "0:U16;起始地址",
        "length": "0:U16;读取字节数",
        "check": "0:u8;全异或校验,覆盖 [cmd,len,addr,length]"
      },
      "res": {
        "sof": "0x5A:u8",
        "status": "0x00:StatusEnum;链路层状态",
        "len": ":U16;PAYLOAD 字节数",
        "data": "0:u8[length];读取到的数据,长度=length",
        "check": "0:u8;全异或校验,覆盖 [status,len,data]"
      }
    },
    "WriteBlock:Frame;写一块数据;cmd=0x04": {
      "req": {
        "sof": "0xA5:u8",
        "cmd": "0x04:CmdEnum:u8;",
        "len": ":U16;字节数",
        "addr": "0:U16;起始地址",
        "length": "0:U16;写入字节数",
        "data": "0:u8[length];写入数据",
        "check": "0:u8;全异或校验,覆盖 [cmd,len,addr,length,data]"
      },
      "res": {
        "sof": "0x5A:u8",
        "status": "0x00:StatusEnum:u8;链路层状态",
        "len": "0x0001:U16;PAYLOAD 字节数",
        "result": "0x00:StatusEnum;业务层结果",
        "check": "0:u8;全异或校验,覆盖 [status,len,result]"
      }
    },
    "GetStatus:Frame;读状态字;cmd=0x05": {
      "req": {
        "sof": "0xA5:u8",
        "cmd": "0x05:CmdEnum:u8",
        "len": "0x0000:U16;无 payload",
        "check": "0:u8;全异或校验,覆盖 [cmd,len]"
      },
      "res": {
        "sof": "0x5A:u8",
        "status": "0x00:StatusEnum:u8;链路层状态",
        "len": "0x0004:U16;PAYLOAD 字节数",
        "statusWord": "0:U32;FPGA 状态字,大端",
        "check": "0:u8;全异或校验,覆盖 [status,len,statusWord]"
      }
    },
    "Reset:Frame;复位 FPGA;cmd=0x06": {
      "req": {
        "sof": "0xA5:u8;",
        "cmd": "0x06:CmdEnum:u8",
        "len": "0x0001:U16;PAYLOAD 字节数",
        "magic": "0x5A:u8;复位魔数,防止误触发",
        "check": "0:u8;全异或校验,覆盖 [cmd,len,magic]"
      },
      "res": {
        "sof": "0x5A:u8",
        "status": "0x00:StatusEnum;链路层状态",
        "len": "0x0001:U16;PAYLOAD 字节数",
        "result": "0x00:StatusEnum;业务层结果",
        "check": "0:u8;全异或校验,覆盖 [status,len,result]"
      }
    }
  },
  "demoContent;示例": {
    "readReg": {
      "req": "A5 01 00 02 00 10 13",
      "res": "5A 00 00 04 DE AD BE EF 26"
    },
    "writeReg": {
      "req": "A5 02 00 06 00 10 DE AD BE EF 36",
      "res": "5A 00 00 01 00 01"
    },
    "readBlock": {
      "req": "A5 03 00 04 00 10 00 04 13",
      "res": "5A 00 00 04 11 22 33 44 40"
    },
    "writeBlock": {
      "req": "A5 04 00 08 00 10 00 04 11 22 33 44 5C",
      "res": "5A 00 00 01 00 01"
    },
    "getStatus": {
      "req": "A5 05 00 00 05",
      "res": "5A 00 00 04 00 00 00 01 05"
    },
    "reset": {
      "req": "A5 06 00 01 5A 5D",
      "res": "5A 00 00 01 00 01"
    }
  }
}