AnsweredAssumed Answered

STM32 Manuals and Schematics Correct

Question asked by jlc.jlsilicon on Jul 26, 2012
Latest reply on Aug 4, 2013 by kele

In Manufacturing my own Boards, and with the assistance of Tsuneo,
I have found Usb Pinout Backwards.
This is after I analyzed the Specs and Schems
- which match my Eagle Pcb Files and my Boards.
And, I tested this from Cable-end to Micro-Pins with a MultiMeter.

The UsbVBus+ and UsbGND are Correct,
but the UsbDm and UsbDp are BACKWARDS.

You are kidding me.  I see the results as you say.  So the schematics are backwards ?
Yes, I use USB-View, besides a Usb packet logger analyzer.
Let me check the Usb connections.

I forgot about this simple issue.  For example, just Google for USB PLUG PINOUT IMAGE , then click the images page.  Notice that the Plug on the Right is labeled Gnd D- D+ V+ , which should be Gnd D+ D- V+.  This error has been on there for years like this - and is still there. 

Bingo ! - That fixes it.
So, looking at the Stm32f4Discovery and Stm3240g and Stm32405_RefMan. 
And scanned over my Eagle Pcb Files which match the Schems and Spec.

p1=UsbVBUS -> PA9
p2=UsbDM     -> res=20R ->  PA11
p3=UsbDP      -> res=20R ->  PA12
p4=UsbID       -> PA10
p5=UsbGND   -> GND

Tsuneo, thanks - for the unique and constructive idea and solution.

From: chinzei.tsuneo

Connection from the D+/D- pins of the USB receptacle to the MCU USB DP/DM pins may be swapped.
 ConnectionStatus: DeviceFailedEnumeration
 Device Bus Speed:      Low   <----------
If the stm32f4 (Unknown device) is detected as low-speed, the D+/D- connections are swapped.