TI shifts process for faster MSP430
Texas Instruments has redesigned its MSP430 microcontroller for a 180nm process, letting the company take advantage of cuts in power consumption and faster transistors to increase the clock speed to 25MHz and open the door to system-on-chip devices that put radio-frequency transceivers onboard.
Launched more than a decade ago as a specialised microcontroller for utility meters the device has a sleep mode that consumes very little power so that it can run for years from a battery TI has gradually expanded the scope of the MSP430 with a series of updates that boosted clock speed from a few megahertz to 16MHz in the most recent iteration. The microcontroller has moved into medical and consumer designs as well as some areas of industrial control.
“A lot of applications are moving to portability: they are going to be battery powered,” said Frank Forster, business development manager EMEA for catalogue DPSs, microprocessors and low-power wireless. “As well as the momentum in the market for low power, customers want more functions. They have security and encryption requirements and are using more advanced man-machine interfaces.”
Moving from a 0.35µm process to the much denser 180nm process has allowed the company to add more on-chip memory up to 256Kbyte of flash with some parts and additional peripherals and execution units.
The first part to launch includes a 32bit integer multiplier and a hardware unit for performing 16bit cyclic-redundancy checks (CRC16). Later devices will add hardware support for AES encryption as well as RF interfaces, such as the sub-1GHz licence-free bands and ultimately Zigbee and the low-power variant of Bluetooth.
To allow the devices to operate in low-power modes, the company has developed a direct-memory access (DMA) controller that works independently of the core processor so that peripherals can deliver data without having to fully wake the part up. As many applications that demand long battery life tend to spend long times with much of the microcontroller shut down, only waking it for brief periods, TI has provided a variety of power-down clocking modes.
For high-stability, the parts can run from an external 32kHz. However, this oscillator may draw more power than desired, so the part can run from its own oscillators. One mode that draws just 200nA but which does not have high accuracy in terms of clocking.
As with earlier MSP430s, the microcontroller uses a frequency locked loop coupled to a digitally controlled oscillator. This approach lets the device wake from sleep in around 5µs.
Image: The MSP430 started off in power and other utility metering applications