1. Meaning of the Error
"112B VOLTAGE PARAMETER ERROR" is an error that occurs when there is a difference
(deviation) of 1.0 V or more between the "operating voltage parameter" set on the
programmer and the "actual target voltage" measured by the programmer (at the
TVccd terminal) during programming.
In Renesas Electronics RL78 series microcontrollers, the flash memory programming
characteristics change depending on the operating voltage. Therefore, in the serial
programming command protocol, it is necessary to notify the microcontroller of the
operating voltage value at the start of communication. The programmer constantly
monitors the voltage of the target microcontroller to ensure safe and reliable
programming, and abnormally terminates the process if the parameter setting value
deviates from the actual measured value (TVccd input).
2. Causes and Countermeasures
■ Cause: Mismatch between the operating voltage setting and the actual supply voltage
Situation 1 (Incorrect Setting):
In the parameter settings of the control software (SWX600), the operating voltage
parameter remains at its initial value (default value: 0V), or a value different from the
actual supply voltage is set (e.g., the setting is 3.3V even though the target is
operating at 5.0V).
Situation 2 (Voltage Drop):
The power supply to the target board is cut off or extremely low, resulting in a
difference of 1.0 V or more between the actual measured voltage and the parameter
setting value.
■ Countermeasures (Avoidance Methods)
We recommend checking the physical connection status first before proceeding
to the software settings. Please verify the following items in order.
[Countermeasure 1] Confirm the power supply and connection status of the target board
Confirm that power is correctly supplied to the target board.
Confirm that the TVccd terminal (or TVcc) of the programmer is correctly connected
to the power supply line of the target board.
[Countermeasure 2] Correctly set the operating voltage parameter in the control software (SWX600)
Change the parameters according to your target operating voltage by following
the steps below.
- Open the remote control software (SWX600) and select the "Parameter Table 2"
tab.
Note: If prompted for a password when selecting the tab, enter AF200 to unlock it.
- In address #143 (operating voltage setting value), set the hexadecimal value
calculated by the following rules.
< Specific Calculation Examples >
If the target voltage is 5.0 V: 50 in decimal ➔ Set 32 in hexadecimal.
If the target voltage is 3.35 V: Truncate the second decimal place to 3.3 V ➔ 33 in decimal ➔ Set 21 in hexadecimal.
After entering the value, be sure to click the "OK" button to save and apply the settings.