# UART interface modules for Cocotb
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GitHub repository: https://github.com/alexforencich/cocotbext-uart
## Introduction
UART simulation models for [cocotb](https://github.com/cocotb/cocotb).
## Installation
Installation from pip (release version, stable):
$ pip install cocotbext-uart
Installation from git (latest development version, potentially unstable):
$ pip install https://github.com/alexforencich/cocotbext-uart/archive/master.zip
Installation for active development:
$ git clone https://github.com/alexforencich/cocotbext-uart
$ pip install -e cocotbext-uart
## Documentation and usage examples
See the `tests` directory and [verilog-uart](https://github.com/alexforencich/verilog-uart) for complete testbenches using these modules.
### UART
The `UartSource` and `UartSink` classes can be used to drive, receive, and monitor asynchronous serial data.
To use these modules, import the one you need and connect it to the DUT:
from cocotbext.uart import UartSource, UartSink
uart_source = UartSource(dut.rxd, baud=115200, bits=8)
uart_sink = UartSink(dut.rxd, baud=115200, bits=8)
To send data into a design with a `UartSource`, call `write()` or `write_nowait()`. Accepted data types are iterables of ints, including lists, bytes, bytearrays, etc. Optionally, call `wait()` to wait for the transmit operation to complete. Example:
await uart_source.send(b'test data')
# wait for operation to complete (optional)
await uart_source.wait()
To receive data with a `UartSink`, call `read()` or `read_nowait()`. Optionally call `wait()` to wait for new receive data. `read()` will block until at least 1 data byte is available. Both `read()` and `read_nowait()` will return up to _count_ bytes from the receive queue, or the entire contents of the receive queue if not specified.
data = await uart_sink.recv()
#### Constructor parameters:
* _data_: data signal
* _baud_: baud rate in bits per second (optional, default 9600)
* _bits_: bits per byte (optional, default 8)
* _stop_bits_: length of stop bit in bit times (optional, default 1)
#### Attributes:
* _baud_: baud rate in bits per second
* _bits_: bits per byte
* _stop_bits_: length of stop bit in bit times
#### Methods
* `write(data)`: send _data_ (blocking) (source)
* `write_nowait(data)`: send _data_ (non-blocking) (source)
* `read(count)`: read _count_ bytes from buffer (blocking) (sink)
* `read_nowait(count)`: read _count_ bytes from buffer (non-blocking) (sink)
* `count()`: returns the number of items in the queue (all)
* `empty()`: returns _True_ if the queue is empty (all)
* `idle()`: returns _True_ if no transfer is in progress (all) or if the queue is not empty (source)
* `clear()`: drop all data in queue (all)
* `wait()`: wait for idle (source)
* `wait(timeout=0, timeout_unit='ns')`: wait for data received (sink)