matt_hsu at openmoko.org
Wed Feb 13 14:32:51 CET 2008
於 三，2008-02-13 於 16:19 +0800，Neng-Yu Tu (Tony Tu) 提到：
> When GSM on with sleep mode (or power saving but still connect to GSM
> network), the GSM module will _flicking_ the power from 1-2mA to couple
> uA, could observed on power supply's LCD panel. If not in power saving
> mode, it will takes about 20mA at idle. But yesterday's suspend
> experiment result was GSM module still takes 40-50 mA, that is way to
I found the root cause of this phenomenon. According to previous mail,
the suspend current could be reduced into 5mA~4mA if the GSM related
GPIOs are configured OUTPUT low.
But this would affect not only GSM incoming call wake-up behavior but
also blocking GSM into sleep mode. Once GSM could not get into sleep
mode itself, its current consumption would become high.
If you don't have GSM related GPIO configuration, then resuming from GSM
incoming call works quite well. Unfortunately, the suspend current would
becomes 18mA. And the current does not always stay at 18mA, it would up
to 30mA periodically.
I try to have GSM related pins as PULLUP configuration. But nothing
changes. It seems that we might need HW solution such as a buffer
between GSM and CPU.
Allen, any ideas?
> It might because some configuration issue or unknown new moko6 GSM
> firmware issue.
> -- Tony Tu
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