SystemRDL for I2C peripheral device registers

[joaohf]

I want to use SystemRDL to define some registers for a peripheral I2C device. I tried the following spec:

regfile eTACHS {
    name = "TACH registers";

    reg {
        name = "Read tach";

        field {
            desc = "Checksum-byte  0xFF means not ready";
        } CHECK[7:0] = 0;
        field {
            desc = "All 16bits should be 0x0000";
        } ZEROS[15:8] = 0;
        field {
            desc = "Value with the RPM";
        } TACH[24:16] = 0;
        field {
            desc = "Rest of the buffer is discarded";
        } RESERVED[31:25] = 0;
    } READ_TACH0 @ 0x0a;

    reg {
        name = "Read tach";

        field {
            desc = "Checksum-byte  0xFF means not ready";
        } CHECK[7:0] = 0;
        field {
            desc = "All 16bits should be 0x0000";
        } ZEROS[15:8] = 0;
        field {
            desc = "Value with the RPM";
        } TACH[24:16] = 0;
        field {
            desc = "Rest of the buffer is discarded";
        } RESERVED[31:25] = 0;
    } READ_TACH1 @ 0x0b;

};

addrmap fan {
    name = "FAN registers";

    eTACHS TACHS;

};

The data size for each I2C command is 32 bits.

The above rdl when I tried to `dump` it, I got the following result:

peakrdl dump fan_i2c.rdl
fan_i2c.rdl:36:7: error: Instance 'READ_TACH1' at offset +0xB:0xE overlaps with 'READ_TACH0' at offset +0xA:0xD
    } READ_TACH1 @ 0x0b;
      ^^^^^^^^^^
fatal: Elaborate aborted due to previous errors

My I2C peripheral device is a set of commands like:

READ_TACH0 = 0x0a
READ_TACH1 = 0x0b
....

The are many commands like that.

With SystemRDL, would it be possible to define a RDL for I2C slave register map ? Maybe some way to avoid overlaps errors ?

Well, I could find a RDL example for I2C specification. 

 

Thanks

 

 

[Richard Weber]

It would appear that you are trying to use register numbers or word addresses to specify byte addresses.  The registers seem to be 32-bits or 4 bytes wide. Left shift the register number or word address by at least 2 bits to get a byte address that avoids the overlap.  Example:

  } READ_TACH0 @ (0x0a << 2);
  } READ_TACH1 @ (0x0b << 2);