# Architectural States

## Defining inputs/states

There are three major types supported in ILAng:

* Boolean -- flags or one-bit signals in the design
* Bit-vector -- multi-bit registers (or sometimes one-bit signals)
* Memory (array) -- buffers, memory system, etc. 

### Input signals

To define an Boolean (one-bit) input signal of the ILA model:

```cpp
auto cmd = m.NewBoolInput("Cmd");
```

To define a bit-vector (multi-bits) type input signal:

```cpp
auto in_addr = m.NewBvInput("InAddr", 32);
auto in_data = m.NewBvInput("InData", 8);
```

Note that, currently, ILAng does not support memory/array typed input signals.  

### State variables

In ILAng, architectural state variables are those that can be updated by the instruction commands. It can be one of the output signals or some intermediate signal/register. To define a Boolean (one-bit) state variable:

```cpp
auto check_pass = m.NewBoolState("CheckPass");
```

To define a bit-vector (multi-bits) state variable, you need to provide the bit-width:

```cpp
auto acc_status = m.NewBvState("AccStatus", 3);
```

You can also define memory/array typed state variables by specifying the bit-width of the address and the data (key and element). 

```cpp
auto buffer = m.NewMemState("Buffer", 32, 8);
```

## Accessing inputs/states

The architectural state variables can be accessed by their name.

```cpp
auto in_addr = m.input("InAddr");
auto buffer = m.state("Buffer");
```

It can also be enumerated.

```cpp
for (auto i = 0; i < m.input_num(); i++) {
    auto ith_input = m.input(i);
}
for (auto j = 0; j < m.state_num(); j++) {
    auto jth_state = m.state(j);
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://bo-yuan-huang.gitbook.io/ilang/modeling/state.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.