This driver controls Renesas serial EEPROM products that employ the latest memory technology to deliver low-voltage operation, low power consumption, high-speed operation, and high reliability. The driver is configured to work with the industry-standard bus of the serial EEPROM.

Application Examples

  • Mobile phones/Cordless phones/Fax machine: Abbreviated dialing systems/Communication History Administration
  • TV/VCR/Remote Control; Channel, Mode setting
  • Measurement devices: Application Software, Log data storage
  • Home telephones: Fine adjustment setting, usage status history administration
  • LCD TV: Parameter settings
  • Camera modules: Adjustment settings
  • DVC: Adjustment settings


  • Data can be read and written simply by calling user API functions.
  • The clock-synchronous serial I/O function of the microcontroller and a single port are used for control.



For systems on which the following devices are mounted, you can use it to control the each devices:

Slave Device Renesas Serial EEPROM
(R1EX25xxx and HN58X25xxx Series)
Master Device Renesas MCU
(RX, RL78, 78K, R8C and M16C Family

Please refer to Supported Memory for detailed Memory Information, Target devices and Products lineup for detailed MCU information.


Application Configuration


Support Memory

R1EX25xxx Series
  • R1EX25512A (512Kbit)
  • R1EX25256A (256Kbit)
  • R1EX25128A (128Kbit)
  • R1EX25064A (64Kbit)
  • R1EX25032A (32Kbit)
  • R1EX25164A (16Kbit)
  • R1EX25008A (8Kbit)
  • R1EX25004A (4Kbit)
  • R1EX25002A (2Kbit)


HN58X25xxx Series
  • N58X25256 (256Kbit)
  • HN58X25128 (128Kbit)


Target Devices and Products lineup

Here we present each software lineup by MCU. Please refer to each application note for a corresponding Integrated Development Environment.



RX Family (FIT module)

The following software is a FIT module, i.e. within our FIT range, so it can easily be combined with other FIT modules. For example, transfer by a DMAC or DTC can easily be handled by combining this module with a DMAC or DTC module, both of which are currently available within our FIT range. (About FIT)


Block Diagram


[Sample Program list]

Slave Device Control Software (Higher-level layer of the software)
Target Memory Application Note Title
R1EX25xxx and HN58X25xxx Series SPI Serial EEPROM RX Family Clock Synchronous Control Module for EEPROM Access Using Firmware Integration Technology



RX (except FIT module), RL78 and 78K Family

Block Diagram


[Sample Program list]

Slave Device Control Software (Higher-level layer of the software)
Target Memory Application Note Title
R1EX25xxx and HN58X25xxx Series
RX Family, RL78 Family, 78K0R/Kx3-L Renesas R1EX25xxx Series Serial EEPROM Control Software



R8C and M16C Family

The following software controls the slave device and master device in systems that include M16C or R8C Family MCUs.

Development Tools Support

Title Description
My Renesas Create a My Renesas account to use our tool download services,
receive e-newsletter/update notifications, and take advantage of our other services.
e-learning Information for studying and learning about microcontrollers and microprocessors.
FAQ Frequently asked questions and useful hints for development.
Forum A forum and community site to share technical information,
questions and opinions with others who use Renesas MCU's.
Tool News Tool release information and other important information.
Operating Environment Information on system requirements and operating environment for the latest
version of tools.
Info on Discontinued Products A list of Renesas software and tools that have been discontinued and
are no longer being offered for new projects.

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