Introduction; Configurator Overview - Microsemi SmartFusion2 Manual

Introduction

There are three oscillator blocks in the SmartFusion2 device that can be used in different use models:
• On-chip 25/50 MHz RC Oscillator - This oscillator generates a 50MHz waveform when the core
supply voltage is 1.2V and 25MHz when the supply voltage is 1.0V. The device core voltage can
be selected from the Libero SoC Device Settings dialog box.
• On-chip 1 MHz RC Oscillator
• Main Crystal Oscillator
The SmartFusion2 oscillators can be used as:
• Dedicated input sources to the FPGA fabric Clock Conditioning Circuitry (CCC)
• Clock sources to any FPGA fabric resource
• Dedicated clock sources to the Micro-controller Sub-system (MSS). You can use the MSS
configurator to:
– Select one of these oscillators as the clock source during Flash*Freeze
– Select one of these oscillators as the clock source to the Real Time Clock (RTC) block
If you intend to use an oscillator as part of your design you must instantiate and configure the Chip
Oscillators core, as described in this document. To configure how the oscillators are used in the MSS,
refer to the MSS configurator handbook and the MSS CCC and RTC sub-block handbooks.
Note: The MSS Watchdog block is always clocked by the 25/50 MHz oscillator and you do not need to
instantiate the Chip Oscillators core in your design and connect it to the MSS to use the Watchdog.

Configurator Overview

The configurator dialog box is organized as follows:
• The Configuration window displays all the configuration options.
• The Preview box shows you a high level block diagram of how your current configuration relates
to the various chip components driven by the various oscillators selected for your design
(Figure
Figure 1 • Oscillators Configuration
1).
3