This document specifies UART hardware IP functionality. This module conforms to the Comportable guideline for peripheral functionality. See that document for integration overview within the broader top level system.
- 2-pin full duplex external interface
- 8-bit data word, optional even or odd parity bit per byte
- 1 stop bit
- 32 x 8b RX buffer
- 32 x 8b TX buffer
- Programmable baud rate
- Interrupt for transmit empty, receive overflow, frame error, parity error, break error, receive timeout
The UART module is a serial-to-parallel receive (RX) and parallel-to-serial (TX) full duplex design intended to communicate to an outside device, typically for basic terminal-style communication. It is programmed to run at a particular baud rate and contains only a transmit and receive signal to the outside world, i.e. no synchronizing clock. The programmable baud rate guarantees to be met up to 1Mbps.
The OpenTitan UART is feature compatible to a specific implementation in Chromium EC. Additional features such as parity have been added.