16-bit secure MCU as first product in Renesas' RS-4 series for multifunction financial and ID smart cards

The successor to Renesas’ AE-4 series, the RS-4 series of 16-bit secure MCUs meets market demands for increased processing performance. The RS45C, the first product to appear in the RS-4 Series, has a CPU core with a performance approximately five times that of previous Renesas Technology products. It reduces the minimum number of execution cycles per instruction to one from the previous two, thereby doubling the processing speed when operating at the same frequency. In addition the RS45C incorporates an on-chip clock oscillator as a new function. The maximum operating frequency has been increased to 20 MHz by switching from an external circuit to a source within the chip for the operating clock. The performance improvements allow faster execution of the complex processing required by multi-application OS such as Java Card and MULTOS.

The RS45C employs Renesas Technology’s exclusive metal oxide nitride oxide silicon (MONOS) EEPROM. It is highly reliable and has a rewrite speed about twice as fast as the type of EEPROM used in the earlier AE45C1. This helps to bring down the cost of initially writing data to the EEPROM when issuing cards and to reduce the time required to process data when the cards are in use in the marketplace. The RS45C also has 224 Kbytes of mask ROM, which can accommodate a general-purpose OS, and 36 Kbytes of EEPROM, which can be used to store multiple applications or data storage.

The DES (Data Encryption Standard) coprocessor of previous products has been upgraded, and the new triple DES coprocessor delivers more sophisticated encryption processing functionality. The RS45C also has a modular multiplication coprocessor providing powerful support for RSA encryption. These two types of encryption functionality enable sophisticated encryption processing at high speed. In addition, peripheral functions make it possible to achieve a high level of security. Examples of the advanced security technology supported include a pseudo random number generator, which rapidly generates random data as an effective security measure for the OS, and an on-chip memory data checking function for helping to thwart fault induction attacks.

There is also an internal clock oscillator. Integrating the clock oscillator on-chip eliminates the problems associated with supplying a clock from an external source. Specifically, the operating speed is no longer dependent on the external clock frequency, so the MCU can always operate at its maximum frequency for the best performance.

There is growing demand in the security-related market for products and systems incorporating security certification by third-party organizations. Renesas Technology has obtained comprehensive security certification under the Common Criteria (CC) information technology security evaluation standard for its MCU products themselves, as well as for its design and production operations. It is expected that the RS45C will be rated security certification level EAL5+ under the latest CC version.

Development tools for the RS45C include High-performance Embedded Workshop, the standard development environment from Renesas Technology, as a user interface covering program development through debugging. This enables developers to work efficiently, using operations they are already familiar with. The E6000 full-spec emulator is also available. It will soon be joined by the E100, which is part of a new series of full-spec emulators offering reduced cost and excellent functionality. The RS45C will be shipped in two forms: wafer and chip on tape (COT).