Question About USB device Lib

[gafsos]

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

[Tesla DeLorean]

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

[gafsos]

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

[Tesla DeLorean]

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.