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Renesas India - Knowledgebase

E1 in 5-V power supply; error message received, emulator unconnected

Latest Updated:10/27/2014


When I use the E1 emulator in the 5-V power supply mode, I get the following error message and cannot connect the emulator to the host machine.

“An error has occurred during the communication with the emulator(FFWERR_COM). Disconnect the debugger and reconnect the USB cable. Then turn on the power of the emulator and initiate the debugger."

High-performance Embedded Workshop:
“A fatal communication error. Disconnect the debugger and check if the emulator is correctly connected to the target board. Then turn on the power of the emulator and initiate the debugger.”

Renesas Flash Programmer:
Error (E1000009) : E1/E20 communication error.
Error (E1000001) : E1/E20 communication time out.
Error (E1017010) : E1/E20 communication error.


There is an abnormality in the USB communication between the host machine and the E1 emulator.
Check to see if the connector connected with the target board is inserted into the correct position, and then reconnect the USB cable before restarting the debugger.

Note that, since the 5-V supply from the E1 depends on the USB power-supply voltage of the PC, the voltage may be less than 5 V.
Or, depending on the load capacitance of the board connected to the E1, even if the board draws less current than the specifications for the E1 allow, the power supply from the E1 may be abnormal due to inrush currents and power from the E1 may be turned off when the E1 is connected.
If corrective action on the above points does not solve the problem, try using an external power supply instead of the power supply from the E1.

When you need reliability in cases such as programming the flash memory during mass production, use an external power supply for the user system instead of the power supply from the E1.

Suitable Products
RX Family
RL78 Family
78K Family
V850 Family
RH850 Family (Automotive only)
CS+ (formerly CubeSuite+)
High-performance Embedded Workshop
E1 [R0E000010KCE00]
Renesas Flash Programmer