kudo1017
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Hi there,
I'm a student and now writting a .sp file(for SPICE simulation) to test the delays of a trisbuffer cell in the cell library designed by myself. Now Im confused by what is the proper way to measure the delays for its 'Enable' signal. Cause for each other cells, I normally just write code like:
***************************************
**for propagation delay, when Enable is active**
.measure tran propagation_ARY TRIG v(A) VAL='3.3*0.5' TD=0NS RISE=1
+ TARG v(Y) VAL='3.3*0.5' TD=0NS RISE=1
**for rise and fall time delay**
.measure tran risetime_ARY TRIG v(Y) VAL='3.3*0.1' TD=0NS RISE=1
+ TARG v(Y) VAL='3.3*0.9' TD=0NS RISE=1
.measure tran falltime_AFY TRIG v(Y) VAL='3.3*0.9' TD=0NS FALL=1
+ TARG v(Y) VAL='3.3*0.1' TD=0NS FALL=1
***************************************
As can be seen, I test it with trigs of certain values in certain rising or falling curves and then minuse it with a target trig. But for enable signal, I don't know whether it will reach such a value as '3.3*0.1' or '3.3*0.9', because 'Y' should be high impedance instead of '0' when ENABLE is passive.
But I checked a formal DATABOOK, this value is actually given, so Im condering how do they measure it? Which value should I set for trigs monitoring?
Regards,
Kellen Wang:grin:
I'm a student and now writting a .sp file(for SPICE simulation) to test the delays of a trisbuffer cell in the cell library designed by myself. Now Im confused by what is the proper way to measure the delays for its 'Enable' signal. Cause for each other cells, I normally just write code like:
***************************************
**for propagation delay, when Enable is active**
.measure tran propagation_ARY TRIG v(A) VAL='3.3*0.5' TD=0NS RISE=1
+ TARG v(Y) VAL='3.3*0.5' TD=0NS RISE=1
**for rise and fall time delay**
.measure tran risetime_ARY TRIG v(Y) VAL='3.3*0.1' TD=0NS RISE=1
+ TARG v(Y) VAL='3.3*0.9' TD=0NS RISE=1
.measure tran falltime_AFY TRIG v(Y) VAL='3.3*0.9' TD=0NS FALL=1
+ TARG v(Y) VAL='3.3*0.1' TD=0NS FALL=1
***************************************
As can be seen, I test it with trigs of certain values in certain rising or falling curves and then minuse it with a target trig. But for enable signal, I don't know whether it will reach such a value as '3.3*0.1' or '3.3*0.9', because 'Y' should be high impedance instead of '0' when ENABLE is passive.
But I checked a formal DATABOOK, this value is actually given, so Im condering how do they measure it? Which value should I set for trigs monitoring?
Regards,
Kellen Wang:grin: