Provide +/-1% accuracy with 40MHz on-chip oscillator and new, battery energy efficient power down modes for overall reduced system power consumption
Renesas Electronics announced the release of its 16 new 16-bit microcontrollers within the R8C/Lx Series: R8C/L3AM, R8C/L38M, R8C/L36M, R8C/L35M. The new R8C/L3xM product groups provide the industry’s most stable accuracy on the high-speed on-chip oscillator along with ultra-low power consumption ranked among the best in the industry. The R8C/L3xM MCUs will comprise a total of four groups ranging from 52 to 100 pins with up to 128 kilobytes (KB) of programmable flash memory. Sample shipments of the first products are scheduled to begin in Q1 FY2011, with samples of the remaining products being shipped shortly after.
The R8C/L3xM groups include a high-speed on-chip oscillator with +/- 1% typical accuracy at room temperature and +/-1.5% guaranteed accuracy in all temperature ranges, including aging variation after factory calibration. The high-speed on-chip oscillator supplies the 40MHz oscillation with 1/2, 1/3, 1/4, 1/5 1/6, 1/7, 1/8 or 1/9 clock division as clock sources to the CPU and also the on-chip peripheral functions. This allows the MCU to communicate with external components via serial interfaces without any other external resonators.
In addition to the accurate high-speed on-chip oscillator, the R8C/L3xM groups offer features that contribute to reduced overall system power consumption, based on the existing R8C/L3xA, R8C/L3xB and R8C/L3xC groups.
The following lists the key features of the four groups.
- +/- 1 percent accurate 40MHz on-chip oscillator. Through improvements to the oscillation generating circuit, the R8C/L3xM offers the industry’s most stable +/- 1 percent accuracy on the 40MHz on-chip oscillator at room temperature. Furthermore, +/- 1.5 percent accuracy is guaranteed, including the aging variation after shipment. This stable oscillation allows users to communicate with external components without external clock sources.
- Energy Efficient Power-Down Modes. Renesas Electronics’ R8C/Lx MCUs have two power-down modes to provide smart power management while reducing overall system power consumption. The CPU and the Real Time Clock (RTC) run with 32 KHz sub clock in power-off mode1, and in the power-off mode 0 only the RAM is retained which reduces the standby current consumption to almost zero. The combination of the two power-down modes offer users easy-to-access means to achieve energy efficient and smart system power management schemes.
- Multi-functional Liquid Crystal Display (LCD) driver combination with Large capacity Flash Memory. The R8C/L3xM groups offer a flexible, multi-functional LCD driver for up to 4×56 (8×52) segments, along with large capacity on-chip Flash memory. Hardware blinking and converting functions are available. Software-selectable segment output of up to 56 pins is available and can be allocated to the segments or to I/O ports. A tuneable LCD power supply booster generates variable common voltage levels to simplify LCD design.
Product Background
In recent years, MCUs incorporating LCD drivers have come into use in a wide range of fields, both as main MCUs in small-scale systems, such as battery-powered healthcare devices or consumer products with LCD panels, and as sub-MCUs in large-scale systems. These include industrial equipment, household electrical appliances, and high-performance office equipment. Demand is growing for reduced power consumption and a wide variety of product types to meet the diverse requirements of products with advanced functionality and battery-powered devices requiring low power consumption.
To meet this demand, Renesas Electronics introduced the R8C/Lx Series of high-performance, low-power MCUs which are now in mass production and have achieved wide adoption in many different markets. Now the second batch of the L3xx products in the series is appearing, providing the most stable and accurate on-chip oscillator and extending the product lineup. The new MCUs retain the advanced functions, performance, and flexibility of the first batch of products in the series, while also achieving ultra-low power consumption rated among the best in the industry.
Product Details
The four groups of MCUs are all built around the Renesas Electronics R8C CPU core, which has a proven track record in the R8C/Lx Series and delivers high performance, excellent functionality and ample flexibility. The R8C is a 16-bit CPU, but the CPU and peripheral functions are linked by an 8-bit bus. The high-speed on-chip oscillator supports a wide range of operating voltages from 1.8 to 5.5V and achieves accuracy of ± 1.0 percent at room temperature and +/-1.5 percent guaranteed. A divider circuit in a later stage is used to produce a variety of oscillation frequencies, allowing the adjustment of the serial communication interface (SCI) baud rate and the timing adjustment of the timers.
Additionally, the following on-chip peripheral functions are provided.
- Power-on reset function
As in earlier products, a function that resets all of the MCU's internal circuits when the device is powered on is provided. The power-on reset function is designed to respond flexibly even when the power supply voltage rise is gradual.
- Voltage-detection circuits
Voltage-detection circuits are provided for detecting external voltages, unlike previous products that only supported one voltage-detection level. The four new groups are equipped with three circuits, providing 20 configurable voltage-detection levels.
- Data Transfer Controller
The four groups are the first LCD MCUs that are equipped with the Data Transfer Controller, which has a proven, shipped record in the H8S family and H8SX family. Easy data transfer is directly available between the register of peripheral functions and on-chip memory, without CPU operation. The Data Transfer Controller shortens the transfer operation and load of the CPU.
- Other
All the new MCUs include an I2C bus interface and a synchronous serial communication unit (SSU) to enable communication with a variety of external chips. There is also an on-chip comparator function, making it possible to monitor analogue signals without the use of an A/D converter for a further reduction in power consumption. Furthermore, the integrated D/A converter provides smoother analogue output than existing PWM (Pulse Width Modulation). These products can be used for a wide range of analogue-control applications.
The four groups of MCUs are all built around the Renesas Electronics R8C CPU core, which has a proven track record in the R8C/Lx Series and delivers high performance, excellent functionality and ample flexibility. The R8C is a 16-bit CPU, but the CPU and peripheral functions are linked by an 8-bit bus. The high-speed on-chip oscillator supports a wide range of operating voltages from 1.8 to 5.5V and achieves accuracy of ± 1.0 percent at room temperature and +/-1.5 percent guaranteed. A divider circuit in a later stage is used to produce a variety of oscillation frequencies, allowing the adjustment of the serial communication interface (SCI) baud rate and the timing adjustment of the timers.
Renesas Electronics’ E8a emulator, an on-chip debugger that uses a single-pin interface, will be offered as a development environment for the new MCUs. Since only a single pin is needed for connection, all of the I/O pins can be used during debugging, enabling efficient program development. Debugging is also efficient because the emulator allows the user to reference and change the contents of the RAM while the program under development is running. The E8a emulator functions not only as an emulator, but can also be used as a Flash memory programmer. The new MCUs will ship either with the flash memory blank or with the flash memory pre-programmed, depending on customers’ requirements. Plans for the future evolution of the Renesas Electronics LCD MCUs include products with enhanced analogue functions, support for even lower voltages, reduced power consumption, and peripheral functions selected for specific applications. Renesas Electronics will continue to extend its product lineup in response to evolving market needs, contributing to the development of products that offer better functionality, lower voltage operation, and less power consumption.
Typical Applications
Typical applications include products in a wide variety of application areas, including battery-powered devices, healthcare devices, household electrical appliances, industrial equipment, security equipment, imaging devices, and office automation equipment.
