How to eye diargam in the USB phy simulation

[mitchell]

Dear All :
I work on USB phy , Does any one know how to simulate the
Eye diagram ? Or any process can fix this problem .


Ps , the simulator is Hspice

 

[uncle_urfi]

You can take the data to Matlab and the plot the eye-diagram there. Please follow these links.

Matlab function
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Simulink blocks:
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**broken link removed**

 

[andy2000a]

it is old problem ..

I ever post it ..

1. create a random like data
2. use folding spice sim time like this

.param width=24ns phase=-0.6ns
.probe tran time2=par('time+phase-int((time+phase)/width)*width')

and probe eye pattern , but you should be know this eye is too idea ..

 

[layes2]

use verilog to generate the test pakage
and simulate use hspice

 

[radigital]

Perform transient simulation of your USB serdes,
over a sufficient time to accumulate the data transmission
and reception over many bits.

In Hspice, depending on the wavefrom viewer tool you use, you
should be able to obtain an eye-diagram of your result
using the built-in function in the waveform calculator.

Otherwise you can super-impose a number of rising
and falling edges of your serdes output, by sampling the
waveform edges at periodic intervals starting from the
edge of one rising edge. The result will be your eye-diagram
of the PHY layer.

Hope this helps.

--Radigital