MSP430F4616: GPIO configuration of LCD driver pins for lowest power

James Bunger

Part Number: MSP430F4616

Is there a recommended setting for PxOUT, PxDIR and PxSEL for the pins that are used by the LCD module to achieve the lowest power consumption?

Thank you very much,

James

over 2 years ago

0 Urica Wang over 2 years ago

TI__Intellectual 2650 points

Hi James,

To lower power consumption, I would configure all GPIO pins to output low (PxOUT = 0x00, PxDIR = 0xFF). For LCD-specific tips, I would suggest looking through this application report on designing with MSP430 LCDs https://www.ti.com/lit/slaa654.

There is also a built-in CCS tool called ULP Advisor that is a static analysis tool that scans your code through a set of low-power coding rules http://software-dl.ti.com/ccs/esd/documents/ccs_ulp_advisor.html.

Thanks,

Urica Wang

0 James Bunger over 2 years ago

Prodigy 170 points

Hi Urica,

Thank you so much for the very quick response.

I see that the LCD Segments are assigned to the LCD operation by settings in the LCD module registers. Do you know if the state of the appropriate PxSEL register has any effect on the power consumption?

Best regards,

James

0 Urica Wang over 2 years ago in reply to James Bunger

TI__Intellectual 2650 points

Hi James,

PxSEL will also have an effect on the power consumption. Looking at section 11.2.7 "Configuring Unused Port Pins" in the User Guide https://www.ti.com/lit/slau056l, to reduce power consumption, unused pins should be configured as I/O function (configure PxSEL to 0x00), output direction (configure PxDIR), and left unconnected (PxOUT is don't care since the pin is unconnected).

Thanks,

Urica Wang

0 James Bunger over 2 years ago in reply to Urica Wang

Prodigy 170 points

Hi Urica,

For the case of a GPIO port/pin that is also a LCD Segment or COM pin, does the PxSEL bit for that port/pin have any effect on power consumption?

Thanks again!

James

0 Urica Wang over 2 years ago in reply to James Bunger

TI__Intellectual 2650 points

Hi James,

For GPIO pins that are also a LCD segment or com pin, the value of PxSEL on power consumption should be negligible. Lowering power consumption on GPIO pins is mainly making sure that unused pins aren't floating.

Thanks,

Urica Wang

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MSP430F4616: GPIO configuration of LCD driver pins for lowest power