.. _qs-uart:

UART
================

.. figure:: ../images/qs-pinout-uart.png
   :width: 50%
   :figwidth: 50%
   :align: right
   :alt:

The QS standard defines three independent UART Ports (UART_A – UART_C).
UART_A is used to output serial debugging information.
UART_C supports hardware RTS/CTS handshake. 

+---------+------------+-------------------------------+----------+---------+
| **Pin** | **Signal** | **Description**               | **type** | **I/O** |
+---------+------------+-------------------------------+----------+---------+
| 89      | UART_RXD_A | Receive Data input signal     | 3V3      | I       |
+---------+------------+-------------------------------+----------+---------+
| 90      | UART_TXD_A | Transmit Data output signal   | 3V3      | O       |
+---------+------------+-------------------------------+----------+---------+
| 91      | UART_RXD_B | Receive Data input signal     | 3V3      | I       |
+---------+------------+-------------------------------+----------+---------+
| 92      | UART_TXD_B | Transmit Data output signal   | 3V3      | O       |
+---------+------------+-------------------------------+----------+---------+
| 93      | UART_RXD_C | Receive Data input signal     | 3V3      | I       |
+---------+------------+-------------------------------+----------+---------+
| 94      | UART_TXD_C | Transmit Data output signal   | 3V3      | O       |
+---------+------------+-------------------------------+----------+---------+
| 95      | UART_CTS_C | Clear to Send input signal    | 3V3      | I       |
+---------+------------+-------------------------------+----------+---------+
| 96      | UART_RTS_C | Request to Send output signal | 3V3      | O       |
+---------+------------+-------------------------------+----------+---------+

.. note:: Keep attention to the unusual DCE naming convention NXP is using for CTS(output)/RTS(input).

.. include:: index.rst