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Is it possible to netlist a cross event in Verilog-A?

I'm trying to implement a prescaler block in verilog-a. The block should trigger a certain behavior when both signal1 and signal2 have rising edges.

// when a signal1 is in rising edge
@(cross(signal1 , 1)) begin

    // check also when signal 2 is in rising edge
    // but this checking should be second in priority
    // which means when signal1 is in rising edge
    // go check if signal 2 is in rising edge

    @(cross(signal2 , 1)) begin
        do something
    end
end

I have been searching for ways to create netlist-like events to achieve this functionality in Verilog-A, but I couldn't find any similar examples. Can you provide guidance on how to approach this situation and implement the desired behavior?

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ShawnLogan over 2 years ago

Dear twix232,

twix232 said:
I'm trying to implement a prescaler block in verilog-a. The block should trigger a certain behavior when both signal1 and signal2 have rising edges.

I think you basically need to set a flag when signal1 undergoes a rising edge and then use the flag in the cross statement for signal2. The cross event syntax includes an "enable" input. When the value of "enable" is non-zero, the cross expression is evaluated. However, if it is zero, it is not evaluated. Hence, if you set your flag to zero and then to, say, 1 when signal1 undergoes a rising edge, the cross event for signal2 will only be evaluated after signal1 undergoes a rising edge. Of course, if you have more than one rising edges of signal1 in your simulation time and want to detect a second signal2 edge, you will need to reset the flag to 0 after the cross event for signal2 occurs.

An example may be found at URL:

https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1O0V000009MpctUAC&pageName=ArticleContent

I hope this helps twix232.

Shawn
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twix232 over 2 years ago in reply to ShawnLogan

Helpful answer thank you
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ShawnLogan over 2 years ago in reply to twix232

Dear twix232,

Great! Thank you for letting us know you made some progress!

Shawn
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ShawnLogan over 2 years ago in reply to twix232

Dear twix232,

Great! Thank you for letting us know you made some progress!

Shawn
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