RL78 F12 (R5F109AAJ1745EM405) Debugging Voltage 2.1V VDD?

I made a quick test and it seems to work fine. I use the debugger in e2 studio 7.1
You have to use external power supply. E1 cannot generate 2.1V power supply.

Hi Frank,
thank you for your fast reply. It's good to know that the µC can debug with 2.1V. We are working with the IAR Embedded Workbench for Renesas RL78 Functional Safety V3.10.2.2086 and it's not working with an external power supply with 2.1V. It might be the Low Power detection. Do you have any experience with that?

Hi Frank,
thank you for your fast reply. It's good to know that the µC can debug with 2.1V. We are working with the IAR Embedded Workbench for Renesas RL78 Functional Safety V3.10.2.2086 and it's not working with an external power supply with 2.1V. It might be the Low Power detection. Do you have any experience with that?

I have a EWRL 3.10.1 and use a simple IAR target board sample code for R5F109GE.
The target is powered with 2.1V and debugging works fine.

Hi Frank,
thank you for your help. It's good to know that it's possible. Unfortunately we didn't got it running with external Power Supply less than 3.8V.
Our setup:
external Vdd = 3.8V on Target and E1
GND (E1 Pins 2,12,13)
Reset (E1 Pins 10,13)(Resistor to Vdd and Capacitor to GND)
Tool0 = E1 Pin 5 ( Resistor to Vdd)
power of the E1 to "Target" and Low Voltage Detection = Off
We get the error: Power off

Best regards
Steffen

This is the board I use. You can also find the circuit diagram.
www.renesas.com/.../QB-R5F109GE-TB.html