Converting Offsets to Values

[mixja]

I understand how to read ROM images in hex and how offsets work. I've been looking at ecuEdit and notice there are several important parameters when converting the value in the ROM memory to a meaningful engine parameter value:

1. Count - the number of values for each row or column. When reading data addresses, the count = rows x columns (for 3D maps) or count = row (for 2D maps)

2. Cell Size (referred to as "Power" in ecuEdit) - the number of bytes that makes up the specific value. AFAIK, either one byte or two bytes. Obviously important when you read values sequentially from memory...

3. Cell Mask (referred to as "Multiplier" in ecuEdit) - for some strange reason, it appears some 8-bit (1 byte) values are stored in 16-bit cells (2 bytes). In this case, you need to AND the cell with a cell mask (e.g. 00FF), effectively removing the 8 MSBs leaving an 8-bit value

4. Format - represents how the data is formatted - e.g. a % with 2 decimal places and so on.

Now first question, am I on the right track with the above description?

Secondly, I see a lot of offsets posted, which is great for a starting point, but how do you determine all of the other logic parameters listed above to derive meaningful values for the various ECU maps and settings? Does the logic vary between ECU or is there a common logic that is applied (e.g. even though the offset varies between ECUs, once you find the data, the algorithms you run the data value through are the same for all ECUs?)