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Verilog A Event (Read 3568 times)

yaxazaa New Member Offline Posts: 6	Verilog A Event Mar 22^nd, 2006, 4:44pm Can someone tell me how to do integration between two events in Verilog-A? Foe example, when signal a passed trigger point, the function starts to do integration, after detected signal b passed trigger point, intergation stop. Thanks.
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Geoffrey_Coram

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Posts: 1998
Massachusetts, USA

Re: Verilog A Event
Reply #1 - Mar 23^rd, 2006, 5:49am

@(initial_step) integ = 0;

@(cross(V(ctrl), +1)) integ = 1; // triggers when V(ctrl) crosses 0 in the positive direction
@(cross(V(ctrl)-2,+1)) integ = 0; // triggers when V(ctrl) crosses 2 in the positive direction

V(out) <+ idt(integ * V(in), 0);

Note that V(ctrl) must start below zero, or else the cross function won't detect a crossing.

If at first you do succeed, STOP, raise your standards, and stop wasting your time.

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Marq Kole

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Eindhoven, The Netherlands

Re: Verilog A Event
Reply #2 - Mar 24^th, 2006, 2:18am

Or use the @(above) event if you want V(ctrl) to be able to start above 0 from the start of your simulation. With @(above) the event is triggered also during (implicit) DC analysis.

@(above(V(ctrl))) integ = 1;
@(above(V(ctrl))) integ = 0;

BTW @(above) is an Verilog-AMS 2.2 feature so may not be available in all simulators yet.

Alternatively, test for V(ctrl) during the @(initial_step)

@(initial_step) integ = (V(ctrl) > 0) ? ((V(ctrl) > 2) ? 0 : 1) : 0;

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