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TE703 Level shifter

Started by whitsydaddy, December 17, 2015, 04:20:31 PM

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whitsydaddy

Hello,
We are currently using a TE0720 on a TE703 carrier board.  We want to use the Processor pins MIO10 and MIO11 on the TE703 for IO from the Zynq processor.  In looking at the schematic there is an I2C level shifter (U7) on those pins with pull-up resistors on the output.  The input voltage to the level shifter is 3.3 V and the output voltage is also 3.3V, so it does not seem to be level shifting anything. Was there a particular reason for this?
We want to use these pins for uart0 from the Zynq and hope to be able to use this by removing the pullup resistors? I would appreciate any thoughts on this.  Thanks, Scott

Antti Lukats

Hi

we added the I2C "buffer" from some consideration, probably to provide one i2c bus that is bit more protected than regular FPGA pins that are sensitive to ESD and overshoot over-voltage.

I would assume you do not need to remove any pullups to use the mio10,11 for uart.

whitsydaddy