Subject: Re: ibischk3 problems
From: Mike LaBonte (mike@labonte.com)
Date: Thu Oct 18 2001 - 15:19:34 PDT
Brian,
You probably are seeing an s2ibis2 function call bug. It depends
on how s2ibis2 was compiled, and on which platform. Check all of
the waveform test .spi files (like a00XXX.spi), and you may see
a test fixture resistor RFIXS2I with both terminals attached to
the same node. So the buffer is running open circuit and goes full
swing.
If you are willing to fix the code, the bug lines are in s2ispice.c,
and looks like this:
sprintf( dummyBuffer, resString[spiceType], "RFIXS2I", nodeList[nodeIndex],
nodeList[++nodeIndex], currentWave_P->R_fixture );
The problem is that order of argument evaluation in C is indeterminate,
and the ++nodeIndex may be evaluated first. Change it to:
sprintf( dummyBuffer, resString[spiceType], "RFIXS2I", nodeList[nodeIndex],
nodeList[nodeIndex+1], currentWave_P->R_fixture );
++nodeIndex;
The same bug appears at other places in that file. If your RFIXS2I
terminals are not shorted, then I don't know what the problem is :-)
Mike LaBonte
Brian Young wrote:
>
> Hello,
>
> I am getting errors from ibischk3, but I can't figure out what
> the problem is. The IBIS file was generated by a methodology in
> development, so there are lots of little problems. Right now,
> there are also big problems:
>
> IBISCHK3 V3.2.7
>
> Checking test.ibs for IBIS 2.1 Compatibility...
>
> ERROR - Model mod.A35_2.5V: The [Rising Waveform]
> with [R_fixture]=50 Ohms and [V_fixture]=2.5V
> has TYP column DC endpoints of 1.15V and 2.45v, but
> an equivalent load applied to the model's I-V tables yields
> different voltages ( 2.52V and 2.50V),
> a difference of 54.34% and 1.87%, respectively.
> ERROR - Model mod.A35_2.5V: The [Rising Waveform]
> with [R_fixture]=50 Ohms and [V_fixture]=0V
> has TYP column DC endpoints of 0.00V and 1.20v, but
> an equivalent load applied to the model's I-V tables yields
> different voltages ( 1.43V and 1.38V),
> a difference of 100.00% and 13.05%, respectively.
> ERROR - Model mod.A35_2.5V: The [Falling Waveform]
> with [R_fixture]=50 Ohms and [V_fixture]=2.5V
> has TYP column DC endpoints of 1.25V and 2.50v, but
> an equivalent load applied to the model's I-V tables yields
> different voltages ( 2.52V and 2.50V),
> a difference of 50.37% and 0.13%, respectively.
> ERROR - Model mod.A35_2.5V: The [Falling Waveform]
> with [R_fixture]=50 Ohms and [V_fixture]=0V
> has TYP column DC endpoints of 0.05V and 1.35v, but
> an equivalent load applied to the model's I-V tables yields
> different voltages ( 1.43V and 1.38V),
> a difference of 96.51% and 2.18%, respectively.
>
> Errors : 4
>
> File Failed
>
> Take for example the first error. Before the start of the rising edge,
> the NFET is holding the voltage low. I can find the holding low voltage
> by finding the point on the PULLDOWN IV curve where 2.5V=V+50*I. Using
> the IV curve entry 1.10 27.69m, I find the voltage to be 1.1V. From the
> [Rising Waveform], R_fixture = 50, V_fixture = 2.500 curve, I get the
> starting voltage as 1.15V. That looks like a match to me, but ibischk3
> comes up with an error and different numbers.
>
> Can someone ID the problem with these errors?
>
> Thanks,
> Brian
>
> -------------------------------------
>
> [ibiS ver] 2.1
> [File Name] test.ibs
> [File Rev] 2.0
> [Date] date
> [Source] rev x.x
> [Copyright] test
> [Component] test1
> [Manufacturer] Motorola
> [Package]
> R_pkg 1m NA NA
> L_pkg 1p NA NA
> C_pkg 1f NA NA
> [Pin] signal_name model_name
> |
> D9 A35 mod.A35_2.5V
>
> [Model] mod.A35_2.5V
> Model_type I/O
> Polarity Non-Inverting
> Enable Active-High
> Vinh = 1.23V
> Vinl = 1.21V
> Cref = 0
> Rref = 0
> Vref = 0
> C_comp 4p 3p 6p
> [Temperature Range] 27 NA NA
> [Pullup Reference] 2.5V NA NA
> [Pulldown Reference] 2.5V NA NA
> [Power Clamp Reference] 2.5V NA NA
> [GND Clamp Reference] 0.0V NA NA
>
> [Ramp]
> |variable typ min max
> dV/dt_r 0.75/0.24n NA NA
> dV/dt_f 0.75/0.09n NA NA
>
> [Rising Waveform]
> R_fixture = 50
> V_fixture = 2.500
> C_fixture = 0p
> L_fixture = 0n
> C_dut = 0p
> R_dut = 0m
> L_dut = 0n
> |Time V(typ) V(min) V(max)
> 1.45ns 1.15V NA NA
> 1.46ns 1.20V NA NA
> 1.47ns 1.95V NA NA
> 1.49ns 2.00V NA NA
> 1.51ns 2.05V NA NA
> 1.52ns 2.10V NA NA
> 1.54ns 2.15V NA NA
> 1.57ns 2.20V NA NA
> 1.60ns 2.25V NA NA
> 1.64ns 2.30V NA NA
> 1.75ns 2.35V NA NA
> 2.57ns 2.40V NA NA
> 8.05ns 2.45V NA NA
>
> [Falling Waveform]
> R_fixture = 50
> V_fixture = 2.500
> C_fixture = 0p
> L_fixture = 0n
> C_dut = 0p
> R_dut = 0m
> L_dut = 0n
> |Time V(typ) V(min) V(max)
> 1.54ns 2.50V NA NA
> 1.57ns 1.80V NA NA
> 1.67ns 1.75V NA NA
> 1.76ns 1.70V NA NA
> 1.84ns 1.65V NA NA
> 1.89ns 1.60V NA NA
> 1.92ns 1.55V NA NA
> 1.95ns 1.50V NA NA
> 1.98ns 1.45V NA NA
> 2.03ns 1.40V NA NA
> 2.07ns 1.35V NA NA
> 2.13ns 1.30V NA NA
> 2.22ns 1.25V NA NA
>
> [Rising Waveform]
> R_fixture = 50
> V_fixture = 0
> C_fixture = 0p
> L_fixture = 0n
> C_dut = 0p
> R_dut = 0m
> L_dut = 0n
> |Time V(typ) V(min) V(max)
> 1.47ns 0.00V NA NA
> 1.49ns 0.70V NA NA
> 1.51ns 0.75V NA NA
> 1.54ns 0.80V NA NA
> 1.56ns 0.85V NA NA
> 1.60ns 0.90V NA NA
> 1.64ns 0.95V NA NA
> 1.72ns 1.00V NA NA
> 1.85ns 1.05V NA NA
> 2.16ns 1.10V NA NA
> 2.38ns 1.15V NA NA
> 2.69ns 1.20V NA NA
>
> [Falling Waveform]
> R_fixture = 50
> V_fixture = 0
> C_fixture = 0p
> L_fixture = 0n
> C_dut = 0p
> R_dut = 0m
> L_dut = 0n
> |Time V(typ) V(min) V(max)
> 1.78ns 1.35V NA NA
> 1.79ns 0.80V NA NA
> 1.82ns 0.60V NA NA
> 1.86ns 0.55V NA NA
> 1.90ns 0.50V NA NA
> 1.93ns 0.45V NA NA
> 1.96ns 0.40V NA NA
> 2.00ns 0.35V NA NA
> 2.04ns 0.30V NA NA
> 2.10ns 0.25V NA NA
> 2.17ns 0.20V NA NA
> 2.30ns 0.15V NA NA
> 3.17ns 0.10V NA NA
> 8.77ns 0.05V NA NA
>
> [Pulldown]
> |Voltage I(typ) I(min) I(max)
> -0.60V -17.34m NA NA
> -0.55V -16.16m NA NA
> -0.50V -14.83m NA NA
> -0.45V -13.48m NA NA
> -0.40V -12.14m NA NA
> -0.35V -10.78m NA NA
> -0.30V -9.38m NA NA
> -0.25V -7.99m NA NA
> -0.20V -6.55m NA NA
> -0.15V -5.17m NA NA
> -0.10V -3.74m NA NA
> -0.05V -2.24m NA NA
> 0.00V -0.89m NA NA
> 0.05V 0.57m NA NA
> 0.10V 2.05m NA NA
> 0.15V 3.42m NA NA
> 0.20V 4.89m NA NA
> 0.25V 6.31m NA NA
> 0.30V 7.66m NA NA
> 0.35V 9.08m NA NA
> 0.40V 10.46m NA NA
> 0.45V 11.87m NA NA
> 0.50V 13.16m NA NA
> 0.55V 14.50m NA NA
> 0.60V 15.83m NA NA
> 0.65V 17.06m NA NA
> 0.70V 18.42m NA NA
> 0.75V 19.64m NA NA
> 0.80V 20.86m NA NA
> 0.85V 22.04m NA NA
> 0.90V 23.22m NA NA
> 0.95V 24.39m NA NA
> 1.00V 25.54m NA NA
> 1.05V 26.60m NA NA
> 1.10V 27.69m NA NA
> 1.15V 28.75m NA NA
> 1.20V 29.73m NA NA
> 1.25V 30.75m NA NA
> 1.30V 31.71m NA NA
> 1.35V 32.66m NA NA
> 1.40V 33.56m NA NA
> 1.45V 34.46m NA NA
> 1.50V 35.33m NA NA
> 1.55V 36.15m NA NA
> 1.60V 36.95m NA NA
> 1.65V 37.76m NA NA
> 1.70V 38.48m NA NA
> 1.75V 39.22m NA NA
> 1.80V 39.94m NA NA
> 1.85V 40.63m NA NA
> 1.90V 41.29m NA NA
> 1.95V 41.91m NA NA
> 2.00V 42.53m NA NA
> 2.05V 43.10m NA NA
> 2.10V 43.69m NA NA
> 2.15V 44.22m NA NA
> 2.20V 44.71m NA NA
> 2.25V 45.21m NA NA
> 2.30V 45.63m NA NA
> 2.35V 46.07m NA NA
> 2.40V 46.48m NA NA
> 2.45V 46.86m NA NA
> 2.50V 47.20m NA NA
> 2.55V 47.52m NA NA
> 2.60V 47.82m NA NA
> 2.65V 48.11m NA NA
> 2.70V 48.38m NA NA
> 2.75V 48.63m NA NA
> 2.80V 48.95m NA NA
> 2.85V 49.38m NA NA
> 2.90V 49.78m NA NA
> 2.95V 49.78m NA NA
> 3.00V 49.78m NA NA
> 3.05V 49.78m NA NA
> 3.10V 49.78m NA NA
>
> [Pullup]
> |Voltage I(typ) I(min) I(max)
> 3.10V -47.76m NA NA
> 3.05V -47.50m NA NA
> 3.00V -47.27m NA NA
> 2.95V -46.99m NA NA
> 2.90V -46.73m NA NA
> 2.85V -46.46m NA NA
> 2.80V -46.18m NA NA
> 2.75V -45.89m NA NA
> 2.70V -45.59m NA NA
> 2.65V -45.31m NA NA
> 2.60V -44.99m NA NA
> 2.55V -44.69m NA NA
> 2.50V -44.38m NA NA
> 2.45V -44.03m NA NA
> 2.40V -43.66m NA NA
> 2.35V -43.31m NA NA
> 2.30V -42.91m NA NA
> 2.25V -42.50m NA NA
> 2.20V -42.06m NA NA
> 2.15V -41.59m NA NA
> 2.10V -41.10m NA NA
> 2.05V -40.57m NA NA
> 2.00V -40.04m NA NA
> 1.95V -39.46m NA NA
> 1.90V -38.82m NA NA
> 1.85V -38.21m NA NA
> 1.80V -37.51m NA NA
> 1.75V -36.82m NA NA
> 1.70V -36.07m NA NA
> 1.65V -35.33m NA NA
> 1.60V -34.55m NA NA
> 1.55V -33.73m NA NA
> | 1.50V -32.88m NA NA
> 1.45V -32.08m NA NA
> | 1.40V -31.27m NA NA
> 1.35V -30.42m NA NA
> | 1.30V -30.80m NA NA
> 1.25V -29.87m NA NA
> | 1.20V -28.94m NA NA
> 1.15V -27.96m NA NA
> | 1.10V -26.99m NA NA
> 1.05V -25.92m NA NA
> | 1.00V -24.89m NA NA
> 0.95V -23.89m NA NA
> | 0.90V -22.83m NA NA
> 0.85V -21.66m NA NA
> | 0.80V -20.50m NA NA
> 0.75V -19.33m NA NA
> 0.70V -18.14m NA NA
> 0.65V -17.00m NA NA
> 0.60V -15.75m NA NA
> 0.55V -14.53m NA NA
> 0.50V -13.26m NA NA
> 0.45V -12.00m NA NA
> 0.40V -10.61m NA NA
> 0.35V -9.30m NA NA
> 0.30V -7.99m NA NA
> 0.25V -6.63m NA NA
> 0.20V -5.32m NA NA
> 0.15V -3.93m NA NA
> 0.10V -2.54m NA NA
> 0.05V -1.16m NA NA
> 0.00V 0.18m NA NA
> -0.05V 1.58m NA NA
> -0.10V 2.95m NA NA
> -0.15V 4.38m NA NA
> -0.20V 5.79m NA NA
> -0.25V 7.12m NA NA
> -0.30V 8.52m NA NA
> -0.35V 10.01m NA NA
> -0.40V 11.30m NA NA
> -0.45V 12.67m NA NA
> -0.50V 14.08m NA NA
> -0.55V 15.49m NA NA
> -0.60V 16.82m NA NA
>
> [GND Clamp]
> |Voltage I(typ) I(min) I(max)
> -0.60V -5.08m NA NA
> -0.55V -4.04m NA NA
> -0.50V -3.04m NA NA
> -0.45V -2.12m NA NA
> -0.40V -1.33m NA NA
> -0.35V -0.71m NA NA
> -0.30V -0.29m NA NA
> -0.25V -0.10m NA NA
> -0.20V -0.02m NA NA
> -0.15V -0.02m NA NA
> -0.10V -0.01m NA NA
> -0.05V -0.01m NA NA
> 0.00V -0.01m NA NA
>
> [POWER Clamp]
> |Voltage I(typ) I(min) I(max)
> 0.00V -0.02m NA NA
> -0.05V -0.01m NA NA
> -0.10V -0.01m NA NA
> -0.15V 0.00m NA NA
> -0.20V 0.03m NA NA
> -0.25V 0.14m NA NA
> -0.30V 0.43m NA NA
> -0.35V 0.95m NA NA
> -0.40V 1.61m NA NA
> -0.45V 2.41m NA NA
> -0.50V 3.39m NA NA
> -0.55V 4.41m NA NA
> -0.60V 5.50m NA NA
>
> [End]
>
> --
> ***************************************************************
> * Brian Young phone: (512) 996-6099 *
> * Somerset Design Center fax: (512) 996-7434 *
> * Motorola, Austin, TX brian.young@motorola.com *
> ***************************************************************
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