The RL78 microcontroller family from Renesas Electronics with theintroduction of the RL78/G14 group of 16-bit which combine the advancedon-chip peripheral functions of the R8C MCU family with thepower-efficient technology of the RL78 family.
The RL78/G14 group of MCUs is suitable for a number of applications, including household appliances, healthcare devices, office equipment and industrial automation systems, as well as medical and consumer products such as motor control, security systems and mobile devices.
In addition to the low-power process technology including an advanced 64MHz-capable 16-bit timer units designed for the precise control of low-end motor systems. These timer peripherals – combined with 5-V support, advanced hardware-based safety features such as RAM parity check and CRC – make the RL78/G14 devices suitable for higher-efficiency household appliances.
To minimize development time, Renesas designed these devices to maintain compatibility with its existing R8C and 78K MCUs, allowing developers to save time by re-using some of their legacy code.
The advanced time modules — Timer RD, Timer RG’, and Timer RJ — are compatible with timers in the R8C MCU family. Timer RD comprises two 16-bit timers capable of operating at 64 megahertz and a pulse wave modulation (PWM) function able to output 6 three-phase waveforms with the amplitude specified by the user.
Timer RG is a 16-bit timer module that can automatically measure the counts of a two-phase encoder in phase counting mode. Timer RJ is a 16-bit timer module that can measure the pulse width or cycle of pulse output or external pulse input.
The RL78/G14 MCU devices integrate a data transfer controller (DTC) and event link controller (ELC), which have a proven track record in the R8C family of reducing the CPU load and lowering power consumption. The DTC enables memory-to-memory data transfers without using the CPU. Compared with the DMA function of the RL78/G13, the DTC supports a larger number of transfer channels and activation sources, and it also enables data transfers from the flash memory.
The ELC allows direct connection between peripherals bypassing the CPU and interrupt controller to provide faster and more deterministic real-time control. It is also possible to use the ELC to start peripheral functions when the CPU is stopped, thereby reducing power consumption.
The MCUs with 96 kilobyte or more flash memory feature two channels of 8-bit D/A converter analog comparators with the window function previously available on the R8C family MCUs. The DAC can be utilized to implement audio playback or to generate high-resolution voltage signals, with minimal external components reducing system cost.
The devices include multiply, divide, and multiply and accumulate instructions in the instruction set of the RL78/G13’s CPU core, eliminating the need to handle overflow interrupts when performing arithmetic operations. In addition, the on-chip debugging functions of the new microcontrollers with 96 KB or more of flash memory now support trace data for up to 256 branches, enabling more efficient system development and evaluation.
The RL78/G14 MCUs are available in flash ROM capacities ranging from 16 KB to 256 KB, RAM capacities from 2.5 KB to 24 KB, and a total of 17 package configurations, including a Quad Flat Package (QFP), a compact Quad Flat Non-Leaded (QFN) package, and a Land Grid Array (LGA) package, with pin counts from 30 to 100 pins.
Renesas Electronics also plans to enhance the RL78/G14 group with devices with up to 512 KB of Flash ROM, 128 pins and 105°C operation for systems like cooking appliances.
Development tools for the RL78/G14 group include the IAR Embedded Workbench, Renesas Electronics’ E1 integrated on-chip debugging emulator, and the IECUBE full-function in-circuit emulator. There are also plans to release a flash programmer and Renesas Starter Kit supporting these new MCUs.