use differential I/O simultaneously

[yickma]

Hi all,

Are there any method to use differential I/O simultaneously?

Firstly, route in_P + in_N pad to pad connects to out_P + out_N.

Secondly, route

IBUFDS ( .I(in_P)
.IB(in_N)
.O (out_put)
);

The purpose to doing this is I need No Delay on first route and the
process "out_put" as normal signal.

Please help.

Thanks!

yickma




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[RCIngham]

Hi all,

Are there any method to use differential I/O simultaneously?

Firstly, route in_P + in_N pad to pad connects to out_P + out_N.

Secondly, route

IBUFDS ( .I(in_P)
.IB(in_N)
.O (out_put)
);

The purpose to doing this is I need No Delay on first route and then
process "out_put" as normal signal.

Please help.

Thanks!

yickma

1. Looks like a Xilinx device - which one?

2. Simultaneously with each other, or something else?

3. How simultaneously? (In femtoseconds, for instance)


---------------------------------------
Posted through http://www.FPGARelated.com

 

[Gabor]

RCIngham wrote:

Hi all,

Are there any method to use differential I/O simultaneously?

Firstly, route in_P + in_N pad to pad connects to out_P + out_N.

Secondly, route

IBUFDS ( .I(in_P)
.IB(in_N)
.O (out_put)
);

The purpose to doing this is I need No Delay on first route and then
process "out_put" as normal signal.

Please help.

Thanks!

yickma

1. Looks like a Xilinx device - which one?

2. Simultaneously with each other, or something else?

3. How simultaneously? (In femtoseconds, for instance)


---------------------------------------
Posted through http://www.FPGARelated.com

Newer Xilinx parts have a IBUFDS_DIFF_OUT primitive which gives access
to inverted and non-inverted inputs. Obviously there will be a delay
from the pad to the output of the buffer - you can't route through the
FPGA with no delay. However the delay to each output should be fairly
well matched.

Normally the only reason to use the IBUFDS_DIFF_OUT primitive is that
you have some unusual connection requirement like using two IDELAY
primitives - not because you need an inverted copy of the input.

-- Gabor