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Kit Review - Renesas Promotional Board for RL78 Series Microcontrollers

Posted by jkvasan on


Product Name: Promotion Board for RL78/G14 MCU


YRPBRL78G13 – Renesas Promotional Board for RL78 Series Microcontrollers 

YRPBRL78 is a humble-looking yet power packed development board released by Renesas. In spite of being called as a promotional board for the RL78 family of microcontrollers, the features of this board not only fulfills most of the standard expectations but surpasses a few of them.

RL78/G13 MCUs

RL78 family combines the advanced features of the 78K and R8C families. Low power consumption and high performance go hand in hand while the 16 bit CISC architecture provides processing power with analog rich functionality.


The G13 chip is suitable for most general purpose applications with peripherals such as DMAC, 10 bit ADC and UART.


The pack contains the YRPBRL78G13 USB development stick, a tiny screw driver (helps in tuning the potentiometer connected to the ADC), a CD which contains the necessary documentation, a GUI to interact with the stick, WriteEZ5 – a flash programming tool and Applilet3 – automatic code generating tool for the RL78.

Measuring about 100 mm by 30 mm, this USB stick appears quite compact for a development tool.  It is powered via USB interface  and supports on-board debugging and flash programming.


Figure 1.YRPBRL78G13

Two 30 pin connectors J1 and J2 provide access to most of the I/O pins including the
AVref pins and the Reset.  Renesas Emulator E1 can be connected via J5. With this kind of arrangement, one could easily make an application board to house this stick as a piggy back board and straight away start their project.

Graphical User Interface

The highlighting feature of this board is the accompanying GUI. This GUI provides seamless communication with the stick through USB and demonstrates functionality of the RL78 from simple I/O functions to  advanced ones like serial interface, RTC, ADC, On chip data flash and Safety Functions. The stick is pre-programmed to be used with the GUI.


Figure 2. GUI - Voltage & Temperature Graphics


The ADC input voltage and temperature monitored by the internal temperature sensor of RL78 are plotted as graphs. By varying the potentiometer R15, we could notice the graph nicely changing to indicate the ADC input voltage variation.



Figure 3 RTC Sync, Interrupts and Setting

Setting the alarm is as easy as an Android phone. You could sync the RTC time to the host PC in which the GUI is running. The RTC interrupt feature can be tested with selectable intervals through a drop-down menu.




Temperature and Voltage measurement values can be written into the Data Flash and read back. Read Read and Write operations on Internal RAM performed. Internal data flash written with temperature and voltage values measured by ADC and read back.

Power Consumption


 Figure 5 HALT, STOP and SNOOZE

The ingenuity of the GUI and also the low power consumption of the RL78 can be well appreciated when the Low Power modes are tested.

J3 provides a means to measure the current consumption of the RL78. The three power modes, namely, HALT, STOP and SNOOZE can be tested just be clicking the relevant buttons.

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    Figure 6 Normal Operation             Figure 7 Halt Mode                           Figure 8 Stop Mode

Figure 6, 7 and 8 are the measurements done by a general purpose multi-meter.


Background and Peripheral CRC, RAM and SFR protection and Internal Clock Frequency measurements are the tests available.

WriteEZ5 – Flash Programming Software

WriteEZ5 is a windows based flash programming software and can be used to download application programs to the YRPBRL78G13. However to program flash through WriteEZ5, ensure that jumpers J6 through J9 are shorted in the right manner.


Applilet3 – Device Driver Code Generator

Applilet3 makes programming easier by way of visually selecting the peripheral functions of RL78 and automatically generating relevant  C code.


On the whole, the YRPBRL78 offers unmatched convenience and freedom to the developers to evaluate the full capabilities of RL78 and learn to leverage  its potential  in their designs.

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