MCU brings High Performance to Low-Power Applications

New MCU consumes 95µA/MHz in active power

Texas Instruments has sponsored the following story


The automation and mobile industries are hungry for devices that minimize power drain on batteries and power supplies. That need, coupled with the desire for greater functionality, is driving development of new and more capable units.

As an answer to these needs, TI has announced a new microprocessor control unit (MCU). The MSP432™ MCU family builds on the highly successful TI MSP430™ line of MCUs. There are currently two versions: the MSP432P401R and the MSP432P401M

Figure 1 – MSP432 Block Diagram

The memory size is the main difference between the two models. For instance, the MSP432P401R has 256KB of Flash memory and 64KB of RAM. Meanwhile, the MSP432P401M has 128KB of Flash and 32KB of RAM.

The MSP432 MCU line has moved from the 16-bit architecture of the MSP430 MCU family to the 32-bit ARM® Cortex®-M4F processor. With this move comes a number of improvements in system functionality.

That being said, the MSP432 MCU platform maintains its ultra-low power needs. For example, the MSP432 MCU has a 32 bit bus structure including separate buses for data and instruction use. For arithmetic operations, MSP432 MCUs have added a hardware divider and an integrated floating point unit (FPU). A block diagram of the MSP432 MCU is shown in Figure 1 above.

The new MCU family has implemented a number of the low power modes originally found in the MSP430 line. For a comparison of their low power modes, refer to Table 1. 

When in active mode, MSP432 MCUs require approximately 95 micro amps per mega hertz operating frequency (95uamps/MHz). In the LPM3 mode, the requirement is approximately 850 n A. The time to recover from sleep mode to Active mode is approximately 10 u seconds.  For a more complete description of the MSP432 MCU reference, visit the dedicated datasheet

Table 1 – Power Modes

MSP430

MSP432

Industry Description

Comments

Active

Active

Active Mode

CPU and peripherals

Low-Frequency Active

Low Power Run

CPU/peripherals < 128KHz

LPM0

LPM0

ARM: Sleep

Peripherals of, CPU off

Low-Frequency LPM0

Sleep+CLK < 128KHz

LPM1

N/A

MSP430 specific mode

 

LPM2

N/A

MSP430 specific mode

 

LPM3

LPM3

ARM: Deep sleep

Standby with RAM and RTC

A/BCLK < 32KHz

Some peripherals available

LPM3.5

LPM3.5

ARM: Shutdown

RTC without RAM

LPM4

N/A

Standby with RAM

No clocks

Some peripherals available

LPM4.5

LPM4.5

ARM: Shutdown

Shutdown

 

TI provides an excellent document for current users of the MSP430 MCU module to migrate to the MSP432 MCU platform. The porting guide explores in detail some of the differences between the two units. In addition, it explains some of the areas that may not be directly applicable. 

Figure 2 – MSP432P401R LaunchPad

Finally, to assist users in the development of new applications or in the porting of applications from another MCU model, TI offers an application LaunchPad. The unit has an MSP432P401R MCU with the 48MHz ARM Cortex-M4F processor. The LaunchPad includes an on-board emulator with TI’s EnergyTrace+™ technology. This allows the user to debug application programs, while measuring the operational current requirements.

All of the MSP432 MCU pins are accessible to users. This enables 20-pin and 40-pin booster packs to be installed for special adaptations. The unit is shown in Figure 2.

Texas Instruments has sponsored this post. They have no editorial input to this post – all opinions are mine. Ray Floyd