Re: initialization order

Hi Xavier,

According to the LRM 2.2 mixed-signal chapter, the analog simulator will
always move first in the transient simulation domain. However, it was
recognized that no such order is implied for the DC solution nor is there
any text in the 2.2 LRM that addresses this issue. The proposed text to
amend this in LRM 2.3 is the following (taken from Draft 2):

8.3.2 Mixed-signal DC analysis

Mixed-signal DC analysis is the process of finding the steady state of the
circuit, which is the DC operating
point for transient and AC analysis. The steady state of the digital
circuit is defined as the final state at time
0 when all analog and digital events are executed. For mixed-signal DC
analysis, the processes of the analog
DC analysis and the digital simulation at time 0 are executed iteratively,
starting with the initialization state
(including analog and digital) defined in circuit initialization (8.3.1),
until all signals at the A/D boundaries
reach steady state. The signal propagation at the A/D boundaries follows
the same scheduling semantics as
are defined in transient analysis in the following sections.

Best regards,
Marq


owner-verilog-ams@server.eda.org wrote on 04-03-2008 18:37:34:

> Hi again,
>
> does anyone have a hint of an answer on this question ?
>
> Thanks,
>    Xav
>
> On Wed, 2008-02-27 at 16:00 +0100, Xavier Bestel wrote:
> > Hi,
> >
> > when you have a design with both a initial block (digital) and an
> > initial_step (in the analog block), is there a designated execution
> > order ?
> >
> > Apparently, there's a Kundert testcase where there's a division by a
> > digital signal, in the initial_step. That would implicitly mean that
the
> > initial block should be ran first by the simulator.
> >
> > However I can't find any thace of this in the LRM. Could someone
> > enlighten me please ?
> >
> > Thanks,
> >
> >    Xav
>
>
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