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PostPosted: Tue May 01, 2012 10:56 am 
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Joined: Thu Dec 10, 2009 9:20 pm
Posts: 324
I do not believe this restriction was stated. If sharing SDA and SCL on a single port is the only requirement (and a restricted I2C implementation is satisfactory) then the single port module should be fine.

For a full I2C compliant solution you need to use two separate ports (1-bit or otherwise).

Many devices do not support clock-stretching, you may even get around this with increased time-outs etc.


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PostPosted: Tue May 01, 2012 12:01 pm 
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Joined: Sun Jul 11, 2010 1:31 am
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Not stated no, but I think it is a reasonable assumption that if he has I2C on
pins 7 and 8 of a 32-bit port, he has other stuff on the other pins on that port :-)


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PostPosted: Tue May 01, 2012 6:11 pm 
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Joined: Wed May 19, 2010 9:42 pm
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To make it 100% clear, yes there are other connections on the 32-bit port. Now Ross makes me think that perhaps this is possible so I'm hoping for some further clarification.

Looking at some of the reference designs I see that the USB Audio shares the 32-bit port with other connections, specifically, 1/2 of the ULPI bus is on the P32A. Since that obviously has to switch between input and output while not impacting the other connections how is that handled?


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PostPosted: Wed May 02, 2012 6:51 pm 
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Do you mean the L1 USB Audio Reference Design? If so all the signals used on the 32bit port are outputs I'm afraid (CODEC reset, USB phy reset, LEDs etc)


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PostPosted: Wed May 02, 2012 8:39 pm 
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Yes, I did mean the L1 USB Audio Reference Design. Looking at the connections I thought at first that the following ULPI data signals were connected to the 32-bit port.

ULPI_DATA0 -- P32A28
ULPI_DATA1 -- P32A29
ULPI_DATA6 -- P32A30
ULPI_DATA7 -- P32A31

But I see now that P8B takes precidence and that is the port the ULPI are "really" connected to.


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PostPosted: Thu May 03, 2012 10:42 am 
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Oh i see. Yes, "Smaller" ports take presidence.


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