The new RL78/I1C MCUs are available in seven versions, with on-chip memory capacities ranging from 64 kilobytes (KB) for low-end single-phase meters, 128 KB for high-end single-phase meters, and 256 KB for three-phase meters; and package pin counts from 64 pins for space-saving needs, 80 pins for single-phase meters aimed for use in emerging countries, to 100 pins for single-phase meters aimed for use in advanced applications.

Key features of the RL78/I1C Group of MCUs:

1) Ability to implement electric power measurement processing and DLMS processing on a single chip

The RL78/I1C integrates an AES (Note 2) hardware engine for this purpose, implementing in hardware the AES GCM (Note 3) mode required by the DLMS standard. In addition, the on-chip phase-locked loop (PLL) boosts the maximum operating frequency from 24 megahertz (MHz) to 32 MHz, and the 32-bit multiplier/multiply-and-accumulate unit dramatically reduces the load imposed by software power calculation with 24-bit data converted by the 24-bit ΔΣs A/D converter.

2) Support for three-phase, four-wire meters

The event link controller function and phase adjustment function coordinate the operation of the four-channel 24-bit ΔΣ A/D converter and three-channel 10-bit Successive Approximation Register (SAR) A/D converter, enabling current and voltage measurement on seven channels.

3) Evaluation and reference kit

The reference kit can be used in the meter development phase to reduce the time required for development.