Answers Database
What kinds of information IBIS Models do and don't provide.
Record #3359
Product Family: Unspecified
Product Line: Unspecified
Product Part: NotDetermined
Problem Title:
What kinds of information IBIS Models do and don't provide.
Problem Description:
URGENCY:Standard
GENERAL DESCRIPTION: IBIS models provide information on I/O characteristics. IBIS models can be free
ly distributed to any customers who request them because these models do not require Xilinx to revea
l any proprietary device technology data.
Solution 1:
IBIS CAN:
1. model best case and worst case models by using the min, max current w/the proper min, max ramp ra
tes.
2. model SSO (Simultaneous Switching Output). These are mainly the package inductance, other associa
ted parasitics and the number of buffers switching. IBIS specifies R, L and C in matrix format and t
he use of a matrix for the inductance accounts for the "loop"inductance i.e. the mutuals between the
pins. Specifying the mutual inductance is necessary to account for SSO event simulation.
3. (v2.1) model RTC(Rise Time Controlled), GTO(Gradual Turn on) or Slew rate controlled outputs. The
se are defined under [Rising Waveform] and [Falling Waveform] keywords.
4. model ground bounce. IBIS contains the the package parasitic information necessary to simulate gr
ound bounce. Even though the data is available within the model file, not all simulators may be able
to use it to simulate ground bounce. Refer to your respective simulator for support.
IBIS CAN'T:
1. provide timing information (i.e. propdelays, skew, etc).
2. support measurement of propagation delays. IBIS is mainly used to simulate transmission lines and
analyze signal integrity issues.
End of Record #3359 - Last Modified: 03/02/98 11:19 |
