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Can i use variables in custom eye mask coordinates?

amarkanteti

Hi,

We are generating custom eye mask for different voltages and data rates. we want to make the eye diagram co ordinates generic. so we used variables in the coordinates. I am using the 6.1.7 version. 

Orginal expression:  

eyeMask(eyeDiagram(v("/E_B2" ?result "tran") 0.0 1.27e-06 2e-08 ?triggerPeriod (1 / VAR("DR")) ?autoCenter t) "s" '(6e-09 2.75) '(8e-09 3.85) '(1.2e-08 3.85) '(1.4e-08 2.75) '(1.2e-08 1.65) '(8e-09 1.65))

 

Modified expression (changes the coordinates to variables):

 

eyeMask(eyeDiagram(v("/E_B2" ?result "tran") 0.0 1.27e-06 2e-08 ?triggerPeriod (1 / VAR("DR")) ?autoCenter t) "s" '(VAR(“tmiddleX1”) VAR(“ VMIDDLE”)) '(8e-09 3.85) '(1.2e-08 3.85) '(VAR(“tmiddleX2”) VAR(“VMIDDLE”)) '(1.2e-08 1.65) '(8e-09 1.65))

 

where:

VAR(“tmiddleX1”) is 6n

VAR(“VMIDDLE”) is 2.75V

VAR(“tmiddleX2”) is 14n

 

These points are middle ones in hexagon shape eye mask. After using the variables we are seeing rectangular waveforms.  Can you please help me out how to use the variables in eye mask's co ordinates.

  • I didn’t test this, but the single quoted lists will prevent evaluation for everything inside the lists. So I think:

    eyeMask(eyeDiagram(v("/E_B2" ?result "tran") 0.0 1.27e-06 2e-08 ?triggerPeriod (1 / VAR("DR")) ?autoCenter t) "s" '(VAR(“tmiddleX1”) VAR(“ VMIDDLE”)) '(8e-09 3.85) '(1.2e-08 3.85) '(VAR(“tmiddleX2”) VAR(“VMIDDLE”)) '(1.2e-08 1.65) '(8e-09 1.65))

    should be:

    eyeMask(eyeDiagram(v("/E_B2" ?result "tran") 0.0 1.27e-06 2e-08 ?triggerPeriod (1 / VAR("DR")) ?autoCenter t) "s" list(VAR(“tmiddleX1”) VAR(“ VMIDDLE”)) '(8e-09 3.85) '(1.2e-08 3.85) list(VAR(“tmiddleX2”) VAR(“VMIDDLE”)) '(1.2e-08 1.65) '(8e-09 1.65))

    The literal numbers don’t matter if they are evaluated or not, because they are literal - but in general using ‘(x y z) means that nothing inside the list is evaluated - it is used literally.

    Andrew.

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