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STR91x - Consumptions

paolo239955
Associate II
Posted on November 16, 2007 at 11:11

STR91x - Consumptions

5 REPLIES 5
paolo239955
Associate II
Posted on May 17, 2011 at 09:41

Ciao,

my name is Paolo from Italy.

On the databook it is written :

''Firmware may designate each GPIO pin to have open-drain or push-pull characteristics.''

''There are no internal pull-up or pull-down resistors on GPIO pins. As such, it is recommended to ground, or pull up to VDDQ with a 100KΩ resistor, all unused GPIO pins to minimize power consumption and noise generation.''

but:

if i have GPIO not used, I can assign they the state of Output push-pull without pull-up?

if i dont use the ADC, how I arrange the pins AVDD and AVREF?

Sorry for my English.

Paolo

ma99lo
Associate II
Posted on May 17, 2011 at 09:41

Hello Paolo. I also have the same question. in my opinion, if the GPIO are disabled by FW, the problem ther is not. I mean that if we set them as inputs, where is the need to pull-up/down them? however, as I complete my prototype I'll inform you. see you soon. Marcello

:)

mtraman
Associate II
Posted on May 17, 2011 at 09:41

Hi

simply connect vddq to avdd and avref. it does no harm if u r not using adc

[ This message was edited by: tvikram on 18-04-2007 15:19 ]

paolo239955
Associate II
Posted on May 17, 2011 at 09:41

Sorry, but in the datasheet of the STR91xF there is written :

''The ADC unit goes to stand-by mode (very low-current consumption) after any reset event. CPU firmware may also command the ADC unit to stand-by mode at any time.''

Where I find how much is such consumption?

m_tibu
Associate II
Posted on May 17, 2011 at 09:41

Hi guys,

the trick to put the pins in output and drive them to 0 or 1, should work well. Remember to don't put any load on that pins.

To reduce power consumption activate the clock only to those peripheral you need. In my experience of IC developer (inside the chip), I can tell you that the power consumption of a logic that is not working is few uA.

I hope this could help you.

Marco

[ This message was edited by: m_tibu on 16-11-2007 15:42 ]