125 lines
2.5 KiB
Markdown
125 lines
2.5 KiB
Markdown
|
# Schema Format
|
||
|
|
|
||
|
|
_**Supported syntaxes: JSON, XML, YAML**_
|
||
|
|
|
||
|
|
The following description uses the JSON syntax
|
||
|
|
|
||
|
|
For examples in different formats, see [example1.yaml](example1.yaml), [example2.yaml](example2.yaml), [example3.json](example3.json) and [example4.xml](example4.xml).
|
||
|
|
|
||
|
|
## Main layout
|
||
|
|
|
||
|
|
A schema contains a dictionary of structures. There must be at least one defined structure named "main"
|
||
|
|
```json
|
||
|
|
{
|
||
|
|
"structures": {
|
||
|
|
"main": {
|
||
|
|
...
|
||
|
|
},
|
||
|
|
"struct1": {
|
||
|
|
...
|
||
|
|
},
|
||
|
|
"struct2": {
|
||
|
|
...
|
||
|
|
},
|
||
|
|
...
|
||
|
|
}
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
## Structure
|
||
|
|
|
||
|
|
A structure has a given number of bits and one or multiple ranges. Each range of bits can have a name, a description and / or values with special meaning (see [Range](#range)). A range's structure can also depend on another range's value (see [Dependencies](#dependencies))
|
||
|
|
|
||
|
|
The range name (or key) defines the left- and rightmost bits (e.g. 7-4 goes from bit 7 to bit 4). Bits are displayed in big-endian, i.e. the leftmost bit has the highest value.
|
||
|
|
```json
|
||
|
|
"main": {
|
||
|
|
"bits": 8,
|
||
|
|
"ranges": {
|
||
|
|
"7-4": {
|
||
|
|
...
|
||
|
|
},
|
||
|
|
"3-2": {
|
||
|
|
...
|
||
|
|
},
|
||
|
|
"1": {
|
||
|
|
...
|
||
|
|
},
|
||
|
|
"0": {
|
||
|
|
...
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
## Range
|
||
|
|
|
||
|
|
A range represents a group of consecutive bits. It can have a name (display in the bit cells), a description (displayed under the structure) and / or values.
|
||
|
|
|
||
|
|
For values depending on other ranges, see [Dependencies](#dependencies).
|
||
|
|
|
||
|
|
> **Note**<br>
|
||
|
|
> In YAML, make sure to wrap values in quotes because some values can be interpreted as octal notation (e.g. 010)
|
||
|
|
|
||
|
|
```json
|
||
|
|
"3-2": {
|
||
|
|
"name": "op",
|
||
|
|
"description": "Logical operation",
|
||
|
|
"values": {
|
||
|
|
"00": "AND",
|
||
|
|
"01": "OR",
|
||
|
|
"10": "XOR",
|
||
|
|
"11": "NAND"
|
||
|
|
}
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
## Dependencies
|
||
|
|
|
||
|
|
The structure of one range may depend on the value of another. To represent this situation, first indicate on the child range the range on which it depends:
|
||
|
|
|
||
|
|
```json
|
||
|
|
"7-4": {
|
||
|
|
...
|
||
|
|
"depends-on": "0"
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
Then, in its values, indicate which structure to use. A description can also be added (displayed above the horizontal dependency arrow)
|
||
|
|
|
||
|
|
```json
|
||
|
|
"7-4": {
|
||
|
|
...
|
||
|
|
"depends-on": "0",
|
||
|
|
"values": {
|
||
|
|
"0": {
|
||
|
|
"description": "immediate value",
|
||
|
|
"structure": "immediateValue"
|
||
|
|
},
|
||
|
|
"1": {
|
||
|
|
"description": "value in register",
|
||
|
|
"structure": "registerValue"
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
Finally, add the sub-structures to the structure dictionary:
|
||
|
|
|
||
|
|
```json
|
||
|
|
{
|
||
|
|
"structures": {
|
||
|
|
"main": {
|
||
|
|
...
|
||
|
|
},
|
||
|
|
"immediateValue": {
|
||
|
|
"bits": 4,
|
||
|
|
...
|
||
|
|
},
|
||
|
|
"registerValue": {
|
||
|
|
"bits": 4,
|
||
|
|
...
|
||
|
|
},
|
||
|
|
...
|
||
|
|
}
|
||
|
|
}
|
||
|
|
```
|