USB Superspeed Peripherals

[Anonymous]

Hi

   

On my boards I have found that if the bootloader is running (USB boot selected PMODE=F11), some GPIO pins are driven avtively. As an example, GPIO[51] is driven low by the FX3. If the FX3 is hold in reset, the GPIOs seem to be in high impedance state. There are also other GPIOs affected, but GPIO[51] is the one I was investigating since it is important for us that this pin is high impedance state.

       

I have found this behaviour of GPIO[51] on our custom hardware with the CYUSB3014 production code 1149 and the Cypress Rev 2 DVK Kit having production code 1113. Has somebody else also observed such behaviour?

       

At this point I would like to get a statement from Cypress, how the bootloader is initialising the GPIOs. As you guys have access to the bootloader code, it should be easy enough to tell us. Thanks.

       

Regards

       

Silvio

[Anonymous]

Hi Silvio,

   

As it is related to bootloader it would be a good idea to discuss this over a tech support case. Please create a tech support case (MyAccount -> MyCases) so that we can take a deeper look into this.

   

Regards,

   

Anand

[LiMa_282146]

Hi,

   

Is there any update on this issue. GPIO50 and 57 also seem to be actively driven. Could Cypress let us know the default states of all the GPIO. They do not all default as inputs and this will cause problems if their initial state is not known

       

Sodafarl

[Anonymous]

I have still an open webcase on this. So far Cypress admitted that they were able to repeat the reported behaviour on GPIO[51] but apparently not all boards tested behaved the same.

       

My feeling was already before that more pins than GPIO[51] are affected and now Sodafarl is finding the same. I think Cypress needs to clarify this asap.

       

-Silvio

[Anonymous]

I'll follow-up with our team and provide an update on this as soon as possible.

   

Regards,

   

Anand

[Anonymous]

In the meantime I got the following information. GPIO[0..32] are still missing though.

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

GPIO#	Pin State
33	Tri-state
34	Tri-state
35	Tri-state
36	Tri-state
37	Tri-state
38	Tri-state
39	Tri-state
40	Tri-state
41	Tri-state
42	Low
43	Tri-state
44	Tri-state
45	High
46	Tri-state
47	Tri-state
48	Tri-state
49	Tri-state
50	Tri-state
51	Low
52	Tri-state
53	High
54	Tri-state
55	High
56	Tri-state
57	Tri-state

[Anonymous]

Silvio,

   

Saw the case. Was just about to post it.

   

Thanks for posting it here.

   

Regards,

   

Anand

[Anonymous]

Our experience on the rev 3 DVK has been that the bootloader won't enumerate over USB if any of the following are being driven during boot:

   

GPIO[0] - GPIO[8]

   

GPIO[10]-GPIO[15]

   

GPIO[18]-GPIO[19]

   

GPIO[29]
 

[Anonymous]

 Has there been any official word from Cypress on this issue? 

[Anonymous]

Hi,

   

GPIO # 33 to 57 are same as Silvio posted above ( Sil posted on 09 May 2012 11:05 PM PST ).

   

GPIO # 0 to 29 are in "Tri-state".

   

GPIO # 30 to 32 are "inputs to the FX3".

   

Thanks,

   

sai krishna.

[Anonymous]

 To force a GPIO to tri-state, please use the API as follows:

   

CyU3PGpioSetIoMode(GPIO_NUMBER,0);

   

-Madhu

[StSt_296371]

Hello,

   

I've got a question regarding the Knowledge Base article "FX3 GPIO Pin Condition During Reset - KBA86731" (http://www.cypress.com/?id=4&rID=91267):

   

The document defines the default GPIO states for "USB Boot mode". What about the "SPI Boot mode"? Do the same default GPIO states apply for this boot mode?

   

Regards,

   

Stefan

   

===============================================================================================

   

2015-03-05 Update:

       

Hello,

   

meanwhile I found the information I'd looked for in the AN76405 "FX3 Boot Options" (see Table #29):

   

http://www.cypress.com/?docID=49862

       

Regards,

   

Stefan