Renesas RA Series Quick Design Guide

Application Note
R01AN5988EU0100 Rev.1.00 Page 1 of 51
Jul.21.21
Renesas RA Family
RA4 Quick Design Guide
Introduction
This document answers common questions and points out subtleties of the MCU that might be missed
unless the hardware manual was extensively reviewed. The document is not intended to be a replacement
for the hardware manual; it is intended to supplement the manual by highlighting some key items most
engineers will need to start their own design. It also discusses some design decisions from an application
point of view.
Target Device
RA4 MCU Series
Contents
1. Power Supplies ........................................................................................................................ 4
1.1 References .............................................................................................................................................. 4
2. Emulator Support ..................................................................................................................... 5
2.1 SWD Interface ......................................................................................................................................... 6
2.2 JTAG Interface ........................................................................................................................................ 7
2.3 Serial Programming Interface using SCI ................................................................................................. 8
2.4 Serial Programming Interface using SCI: Devices with Arm
®
TrustZone
®
Support ................................ 9
2.5 Multiple Emulator Interface .................................................................................................................... 10
2.6 Software Setups for Emulator Connections .......................................................................................... 11
2.6.1 SWD and JTAG Interfaces .................................................................................................................. 11
2.6.2 Trace Port ............................................................................................................................................ 11
3. MCU Operating Modes .......................................................................................................... 12
4. Option Setting Memory .......................................................................................................... 12
4.1 Option Setting Memory Registers ......................................................................................................... 15
5. Clock Circuits ......................................................................................................................... 15
5.1 Reset Conditions ................................................................................................................................... 16
5.2 Clock Frequency Requirements ............................................................................................................ 16
5.2.1 Requirements for USB Communications ............................................................................................ 17
5.2.2 Requirements for Programming and Erasing ROM or Data Flash ...................................................... 17
5.3 Lowering Clock Generation Circuit (CGC) Power Consumption ........................................................... 17
5.4 Writing the System Clock Control Registers ......................................................................................... 17
5.5 Clock Setup Example ............................................................................................................................ 18
5.6 HOCO Accuracy .................................................................................................................................... 19
5.7 Flash Interface Clock ............................................................................................................................. 19
5.8 Board Design ......................................................................................................................................... 19
5.9 External Crystal Resonator selection .................................................................................................... 20

Renesas RA Series Specifications

General

Brand	Renesas
Model	RA Series
Category	Microcontrollers
Language	English