LAPIS Semiconductor (a ROHM Group company) has announced the development of the industry’s first* single-chip low power microcontroller that combines existing microcontroller functions optimized for home appliances with a high-fidelity, low power audio playback function. Existing microcontrollers for home appliances typically do not include audio playback functionality, making it necessary to add extra chips that integrate voice synthesis and a speaker amp.
The “ML610Q380” combines LAPIS Semiconductor’s market-proven low-power 8bit RISC “U8 core” with high-fidelity voice synthesis capability and a high output speaker amp. A PWM circuit for IGBT control is also built in, along with an LCD driver. Additional features include compatibility with 5V power supplies and hardware-based audio playback operation that eliminates the need for software processing by the CPU.
In recent years, the trend in the consumer electronics sector has been towards ‘universal’ designs that make it easy for virtually anyone to operate, as well as ‘eco-friendly’ devices that feature low power consumption in order to save energy and minimize environmental impact. With this in mind the “ML610Q380” integrates a number of functions required for compact appliances on a single chip, including a standby function that utilizes minimal power.
For example, in rice cookers AC power is used for cooking rice or keeping it warm, while battery power is employed for the timer function and clock when the unit is powered down. When only the clock function is in operation the supply current is 3.0µA or less (except when charging/discharging the panel load), making operation possible for extended periods without replacing the battery. This capability can also be applied to other compact appliances.
Adding audio functionality to remote controllers is also easily enabled by simply replacing the microcontroller and adding a speaker. And for applications requiring longer playback time large capacity P2ROM memory-equipped models are available.
In addition, middleware is typically used for audio playback with a microcontroller. However, LAPIS Semiconductor provides a hardware-based high-fidelity voice synthesis engine that offers a number of advantages over middleware:
- Audio playback is processed using dedicated, market-proven hardware that eliminates the need for CPU processing, allowing for fast, error-free program execution
- The built-in low-pass filter and speaker amplifier eliminates the need for external parts
- The single-chip configuration minimizes the risk of audio deterioration caused by noise radiation and contamination that occur in the components and circuits that lead up to the speaker
Key Features
- Proprietary RISC CPU “U8 Core
The high-speed CPU is capable of processing 1 instruction per clock cycle via a 3-stage pipeline parallel processing*4 architecture.
- Built-in PWM circuit for IGBT control
Equipped with a PWM output circuit for controlling IGBTs. It can operate two channels alone or concurrently.
- Multiple audio compression methods and low-pass filter for high-fidelity audio built in
A variety of voice synthesis methods are incorporated, including 4bit ADPCM2, 8bit non-linear PCM, 8bit PCM, and 16bit PCM, along with different sampling frequencies (6.4, 8.0, 10.7, 12.8, 16.0, 21.3, 25.6, and 32kHz), allowing the user to combine them as needed. In addition, the integrated low-pass filter provides clear, natural audio playback.
- 0.6W output Class AB speaker amplifier incorporated
The included Class AB speaker amplifier provides excellent output quality and loud volume, making it ideal for voice guidance applications.
- 16Mbit P2ROM-equipped models also offered (ML610Q383/384/385)
The ML610Q383/384/385 series includes a range of memory sizes, from 128Kbyte Flash ROM to 16Mbit P2ROMTM, ensuring compatibility with a variety of requirements, including long audio playback and voice guidance. P2ROM™ capacities: 4Mbit (ML610Q383), 8Mbit (ML610Q384), 16Mbit (ML610Q385)
- On-chip debugger
Connecting with an on-chip debug emulator (µEASE) allows for software debugging during operation and Erase/Write operations of Flash memory mounted on board, reducing development time considerably.
- Clock generator circuits switch between external and internal oscillator modes
The low-speed clock generator circuit enables switching between 32.768kHz crystal and internal RC oscillation (32.7kHz), while the high-speed clock generator circuit can switch between internal PLL oscillation, crystal/ceramic oscillation, or external clock input. Selecting the internal oscillator mode will enable low- and high-speed clock generation without connecting to an external oscillator.
Applications
- Compact appliances such as IH rice cookers
- IH cooking heaters
- Audio remote controls
- General home electronics
- Toys
- Remote controllers
- Health and fitness
