Renesas RL78 Application Note

RL78 Debugging Functions Using the Serial Port
Introduction
This application note describes how to use the RL78 debugging functions using the serial port.
Target Device
RL78
Contents
1. Overview ................................................................................................................................. 4
1.1 Overview of COM Port debugging ........................................................................................................... 4
1.2 Applicable devices ................................................................................................................................... 4
2. User system design ................................................................................................................. 5
2.1 Example of recommended connection between USB-to-serial conversion adapter and MCU............... 5
2.1.1 General RL78 family connectivity .......................................................................................................... 5
2.2 Things to keep in mind when connecting ................................................................................................ 6
2.2.1 RESET# pin ........................................................................................................................................... 6
2.2.2 TOOL0/TOOLTxD/TOOLRxD pins ........................................................................................................ 8
2.2.3 GND ....................................................................................................................................................... 9
2.2.4 Power supply voltage ............................................................................................................................ 9
3. Usage notes .......................................................................................................................... 10
3.1 Power on/off .......................................................................................................................................... 10
3.1.1 Power supply sequence ...................................................................................................................... 10
3.2 MCU resources that are used ............................................................................................................... 11
3.2.1 Securing the debug monitor area ........................................................................................................ 12
3.2.2 Securing the stack area for debugging ............................................................................................... 13
3.2.3 Setting the on-chip debug option byte area ........................................................................................ 14
3.2.4 Setting the security ID ......................................................................................................................... 15
3.3 Reset ..................................................................................................................................................... 16
3.3.1 Behavior after reset ............................................................................................................................. 16
3.3.2 Registers after reset ............................................................................................................................ 16
3.3.3 Pin reset during break ......................................................................................................................... 16
3.4 Flash memory ........................................................................................................................................ 16
3.4.1 Debugging notes for self-programming ............................................................................................... 16
3.4.2 Voltage at which flash memory cannot be written and operation in flash operation mode ................. 17
3.5 GDIDIS function ..................................................................................................................................... 18
3.6 MCUs that are used in debugging ......................................................................................................... 18
3.6.1 Use in mass-production products ........................................................................................................ 18
R20AN0632EJ0100 Rev.1.00
Jul.20.21
Application Note
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