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Visitor
Visitor
6,252 Views
Registered: ‎04-21-2016

Constraining communication interface

Hi,

 

I'm having difficulty constraining (in .xdc) my pins for communication interfaces in general (SPI and IIC at least). For example, in my Block Design, I created an Interface Port of type spi_rtl. I connected that interface port to the AXI Quad SPI IP in my Block Design. Now, my interface is composed of the following signals:

 

adc_spi_io0_i

adc_spi_io0_o

adc_spi_io0_t

adc_spi_io1_i

adc_spi_io1_o

adc_spi_io1_t

etc...

 

What puzzles me is the _i, _o and _t for each IO. I'm don't know how to write, in my .xdc, that this io0 will be used as MOSI. Will this be the correct way to go (and I ignore the _i and _t pins?):

 

set_property PACKAGE_PIN C16 [get_ports adc_spi_io0_o]
set_property IOSTANDARD LVCMOS18 [get_ports adc_spi_io0_o]

 

Thanks,

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2 Replies
Mentor
Mentor
6,207 Views
Registered: ‎06-16-2013

Re: Constraining communication interface

Hi dt_novo

 

If the design has a communication interface via Quad SPI, you describe the constraint for input and output.

I guess "adc_spi_io*_i"  is for input and "adc_spi_io*_o" is for output and "adc_spi_io*_t" is for control of output buffer.

I describe the example for it.

Please modify it by yourself.

 

[example]

- Input

set_input_delay -max <maximum value> -clock <related clock> <port name>

set_input_delay -min <minimum value> -clock <related clock> <port name>

 

- Output

set_case_analisys <1 or 0 (Enable output mode)> <control pin of output buffer>

set_output_delay -max <maximum value> -clock <related clock> <port name>

set_output_delay -min <minimum value> -clock <related clock> <port name>

 

[note]

I guess you need to add "-clock_fall" option. But it's related with your design.

 

Thank you.

Best regards,

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Visitor
Visitor
5,978 Views
Registered: ‎04-21-2016

Re: Constraining communication interface

Hi,

 

thanks for your answer. This, combined with the following link I found, I think I have all the elements to needed!

https://forums.xilinx.com/xlnx/board/crawl_message?board.id=NewUser&message.id=34851

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