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Re: [802.3_SPMD] state diagrams - question

Lennart – very good to heard from you.  In fact, I was thinking of you, and what we did in 802.3bt, when I wrote this.  I think that for now, I have found a good-enough solution to do what I want, without inventing new nomenclature.  After looking at my own email, it turns out that the convention added in 802.3bt (IF-THEN-ELSE) along with separating a couple of the cases that really needed to be separated anyways, appears to solve the problem nicely.  The thing about switch/case statements that I did NOT like is that they have the potential to be abused to collapse what really should be separate states into a single box with a bunch of cases…  After all, what is a state controller other than an state indicator, a set of actions for each value, and determining the next state indicator…  exactly what a switch/case statement does.

 

I hope there is some chance we get to see you soon, maybe when we are in Hamburg in September.

 

George Zimmerman, Ph.D.

President & Principal

CME Consulting, Inc.

Experts in Advanced PHYsical Communications

george@xxxxxxxxxxxxxxxxxxxx

310-920-3860

 

From: Lennart Yseboodt <00000b30a2081bcd-dmarc-request@xxxxxxxxxxxxxxxxx>
Sent: Thursday, June 27, 2024 4:43 AM
To: STDS-802-3-SPMD@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_SPMD] state diagrams - question

 

Classified

 

Hi George,

 

If you recall we encountered a similar limitation during 802.3bt, when we needed an IF/ELSE statement.

The solution then was to create the mechanism for it for Clause 145.

Below you already describe what you want, you could add a “Conventions” clause and create your favorite flavor of a SWITCH statement. You can point to and build upon the state diagram conventions in Clause 145 (by many considered one of the very finest Clauses in all of 802), which will get you operator precedence and an IF THEN ELSE construct already.

 

Tip: don’t forget to add a keyword that applies when none of the cases is true. Also define what happens if multiple are true.

 

Kind regards,

 

Lennart

 

From: George Zimmerman <george@xxxxxxxxxxxxxxxxxxxx>
Date: Wednesday, 26 June 2024 at 20:35
To: STDS-802-3-SPMD@xxxxxxxxxxxxxxxxx <STDS-802-3-SPMD@xxxxxxxxxxxxxxxxx>
Subject: [802.3_SPMD] state diagrams - question

CAUTION: This email is from outside the organization. Do not click on links or open attachments unless you trust the sender.

 

Does anyone know of an example of something like a “switch/case” construct in the 802.3 state diagrams?

 

I am looking for an elegant recursive solution that looks like:

 

Switch ( index )

Case 1:  do_x

Case 2: do_y

Case 3: do z,

End

….

 

Instead of writing a whole string of if-then-else:

If(index = 1) do_x; ELSE

If (index = 2) do_y; ELSE

If (index = 3) do_z); END

 

 

George Zimmerman, Ph.D.

President & Principal

CME Consulting, Inc.

Experts in Advanced PHYsical Communications

george@xxxxxxxxxxxxxxxxxxxx

310-920-3860

 

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