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Question About USB device Lib

gafsos
Associate II
Posted on June 24, 2012 at 14:23

Hello

I'm working on USB device library V3.3.0; I'm new be in STM32 USB; I have some question:could you please help me

1/ I don't understand why SYSCFG module clock is used for the USB disconnect feature ?

2/ What GPIO_AINConfig() function do exactelly ?

3/ EXTERNAL_PULLUP and INTERNAL_PULLUP what are the differences and how they work ?

4/ PWR_EnterSTOPMode () is STM32 in STOP mode ? I measured  IDD I get a high value around (2mA)

5/What Get_SerialNum(void) fuction do ??

Tanks

Abdul Kalam

3 REPLIES 3
Posted on June 24, 2012 at 14:35

Isn't the most current USB library V2.1.0 (March 2012)

1) Probably because it uses EXTI functions

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gafsos
Associate II
Posted on July 02, 2012 at 00:35

thank you clive1 for your answer, do you have please any idea about the other questions ?

abdul

Posted on July 02, 2012 at 19:22

5) A unique serial number for your USB peripheral will permit Windows to recognize and use settings (ie COM#) for that peripheral regardless of which USB socket you plug it into.

4) Don't know, large static current may depending on GPIO settings, and external circuitry/draw.

3) The internal pull-up is only an option for the STM32L15x parts, and presumably relates to detecting if the bus is connected, and the states of D+/D-

2) It would appear to float/tri-state all the GPIO's by making them inputs, and not sink/source drive current.
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