# SVA Issue

**URL:** <https://verificationacademy.com/forums/t/sva-issue/42093>\
**Category:** SystemVerilog\
**Tags:** systemverilogassertionSVA, SystemVerilog\
**Created:** [August 10, 2023, 9:09am UTC](https://verificationacademy.com/forums/t/sva-issue/42093 "2023-08-10T09:09:18Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![nnn314](https://verificationacademy.com/forums/letter_avatar_proxy/v4/letter/n/7ab992/32.png) [@nnn314](https://verificationacademy.com/forums/u/nnn314)\
**Post date:** [August 10, 2023, 9:09am UTC](https://verificationacademy.com/forums/t/sva-issue/42093/1 "2023-08-10T09:09:18Z")

</div>

Hey,

I have the following scenario:

[scenario image](https://imgtr.ee/image/Szbov)

One valid transaction is considered when VALID & RDY are both high.  
Specification states that EOL must be 1 valid transaction wide.  
That is, the fall of EOL can only occur when VALID & RDY are both high.  
How can I write an assertion for it?  
I was able to solve it with an initial-begin block but, it’s not elegant.  
The assertions I tried writing doesn’t catch that.

Thanks in advance.

---

<div class="post-metadata">

**Author:** ![user49](https://verificationacademy.com/forums/user_avatar/verificationacademy.com/user49/32/1084_2.png) [@user49](https://verificationacademy.com/forums/u/user49)\
**Post date:** [August 10, 2023, 5:37pm UTC](https://verificationacademy.com/forums/t/sva-issue/42093/2 "2023-08-10T17:37:09Z")

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_In reply to [nnn314](https://verificationacademy.com/forums/t/sva-issue/42093):_

I would have liked to see your code. Anyway,

```verilog

// the fall of EOL can only occur when VALID & RDY are both high.
ap_v2eol: assert property(@posedge clk) valid && rdy |=> eol); 

```

Ben Cohen  
[Ben@systemverilog.us](mailto:Ben@systemverilog.us)  
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