User Guide

3
Introduction
The SmartFusion2 Microcontroller Subsystem (MSS) provides two MMUART hard peripherals (APB_0
and APB_1 sub busses) with Full/Half Duplex, Asynchronous/Synchronous mode and Modem interface
option.
On the MSS Canvas, you must enable (default) or disable each MMUART instance based on whether it
is being used in your current application. Disabled MMUART instances are held in reset (lowest power
state). By default, ports of enabled MMUART instances are configured to connect to the device Multi
Standard I/Os (MSIOs). Note that MSIOs allocated to a MMUART instance are shared with other MSS
peripherals. These shared I/Os are available to connect to MSS GPIOs and other peripherals when the
MMUART instance is disabled or if the MMUART instance ports are connected to the FPGA fabric.
The functional behavior of each MMUART instance must be defined at the application level using the
SmartFusion2 MSS MMUART Driver provided by Microsemi.
In this document, we describe how you to configure the MSS MMUART instances and define how the
peripheral signals are connected.
For more details about the MSS MMUART hard peripherals, please refer to the SmartFusion2 User
Guide.