MOD54415 pinout clarification, J2-17&18, I2C2 USB OTG input

[barttech]

On Rev 1.7 and greater MOD54415s, are pins J2-17 and J2-18 input-only when used as PIO? I think that is what the DS says, I'm just unclear if that only applies to the OTG, or the PIO.
A search found a topic that had a link to
http://www.netburner.com/component/docm ... ix?Itemid=
but that link is a 505 now.
Is the product MOD54415 I2C2 rev 1.6, and the others are 1.7?
Is there a valid link to this change notice?
Sam

[barttech]

I found the right link:
http://www.netburner.com/support/docume ... ignals-fix
Still a little unclear, on the MOD54415s that I just ordered, will they be V1.9, and are there zero-ohms I can place to get the old I2C2 functionality? Where does it show what to put where on the module, or does NB do that prior to shipping?
Thanks,
Sam

[mbrown]

Hi Sam,

If you just go to the NetBurner store and buy a product, you should get the latest production of that product. In this case, you would get the MOD54415 v.1.9 with 0 ohm resistors on the USB OTG lines. From time to time, people do call and ask about getting custom products made and we will generally do that in quantity. Sometimes, we build a few extras and have them in stock. However, there is no landing page in the store to order them, and you'd actually have to contact sales (sales@netburner.com) see if we have any. If that's what you did, you'll likely get the alternate stuffing for that part.

You can always modify the part after it arrives however, and I believe for the MOD54415 and MOD54417, the resistor numbers on the PCN are up to date to allow that. All the resistors in questions should be near the J2-17 and J2-18 pins, the pairs of USB selection resistors each sharing 3 pads, and the I2C2 pins not far away. Note: The first shipping versions of the MOD54417 will be revision 1.1, but it will be pin compatible with the MOD54415 down to the selectable resistors.

[barttech]

Thanks!
When the pins are wired for the USB option, are pins J2-17 and J2-18 input-only when configured as PIO?
Sam

[mbrown]

Sorry I forgot you had asked about that. The input only note is for any of the USB lines. Since they do not have a GPIO alternate function, we can only use the bit in the USB registers to monitor the state of the lines. Therefore we can't drive them as we would a GPIO line, but we can read them. By moving the resistors to the I2C lines however, you'd be able to use them as GPIO. It looks like the software (pinconstant.h & pins.cpp) assumes they are in the I2C state. If you want to read the USB pins you'll have to address the USB registers directly. I believe we have an example of that, I'll just do a little looking around and get back to you.

[mbrown]

To use pins 17 and 18, you will need to read the "portsc1" register of the USB OTG module and look at bits 10 and 11.

A read for pin 17 or 18 would end up being:

bool pin17_state = sim2.usb_otg.portsc1 & 0x00000400;
bool pin18_state = sim2.usb_otg.portsc1 & 0x00000800;

[barttech]

OK,
But if I changed the zero ohms for I2C2 operation, then I could use the library GPIO functions as usual?
Sam

[roland.ames]

Yes

the library gpio pin software assumes that:
J2-17 is connected to ssi0_RXD / PH7 / I2C_SDA / SIM1_VEN (processor C12)
J2-18 is connected to ssi0_TXD / PH6 / I2C_SCL / SIM1_DATA (processor C13)

[sblair]

Glad to hear you kept the I2C2 option on the 417 version too! I was wondering about that as I've got some projects coming up that it would be useful for.