Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [802.3_RTPGE] Clause 45 updates



Colleagues,

I would like to point out that the change in question was in response to IEEE P802.3 (IEEE 802.3bx) Revision to IEEE Std 802.3-2012 initial Working Group ballot comment #58. The comment requested that consistent text be used to describe reserved registers and bits in Clause 45.

Please refer to IEEE Std 802.3-2012, 45.2.
"The operation of an MMD shall not be affected by writes to reserved and unsupported register bits, and such register bits shall return a value of zero when read."

The description of reserved bits in IEEE Std 802.3-2012 Table 45-11 is consistent with this: "Value always 0, writes ignored".

A R/W bit for which writes are ignored and the value returned is always zero is consistent with the definition of an RO bit. As I recall, this was a consideration of the ballot resolution committee during the development of the comment response. I have checked as far back as IEEE Std 802.3-2005 and the text in 45.2 has been the same (it has not been the case that reserved bits can be written/read as 1).

I hope this helps to clarify the situation.

Best regards,
--Adam


On Thu, May 14, 2015 at 7:00 PM, Marek Hajduczenia <marek.hajduczenia@xxxxxxxxx> wrote:

That is a good discussion for P802.3bx, I believe

 

From: William Lo [mailto:williaml@xxxxxxxxxxx]
Sent: Thursday, May 14, 2015 6:56 PM


To: Marek Hajduczenia; STDS-802-3-RTPGE@xxxxxxxxxxxxxxxxx
Subject: RE: [802.3_RTPGE] Clause 45 updates

 

Hi Mark,

 

OK.  I wasn’t aware of the .3bx activities on this.  We can comply for 1000BASE-T1.

But this change in .3bx makes existing parts in the field technically non-compliant as the reserved registers values can be written

into and read as 1.

 

Thanks,

William

 

 

From: Marek Hajduczenia [mailto:marek.hajduczenia@xxxxxxxxx]
Sent: Thursday, May 14, 2015 3:43 PM
To: William Lo; STDS-802-3-RTPGE@xxxxxxxxxxxxxxxxx
Subject: RE: [802.3_RTPGE] Clause 45 updates

 

I understand, but we will be emending next revision of the standard, so we need to be looking at 802.3bx as the base for our draft J

 

Marek

 

From: William Lo [mailto:williaml@xxxxxxxxxxx]
Sent: Thursday, May 14, 2015 6:35 PM
To: Marek Hajduczenia; STDS-802-3-RTPGE@xxxxxxxxxxxxxxxxx
Subject: RE: [802.3_RTPGE] Clause 45 updates

 

Hi Marek,

 

Did all this get changed in 802.3bx?

The previous one in 802.3-2012_SECTION4.pdf which was in the 2015 disk has them as R/W.

 

Thanks,

William

 

 

Thanks,

William

 

From: Marek Hajduczenia [mailto:marek.hajduczenia@xxxxxxxxx]
Sent: Thursday, May 14, 2015 3:18 PM
To: William Lo; STDS-802-3-RTPGE@xxxxxxxxxxxxxxxxx
Subject: RE: [802.3_RTPGE] Clause 45 updates

 

William,

 

I checked latest 802.3bx draft and it seems to be correct there.

 

cid:image001.png@01D08E68.0C2FDA30

 

Marek

 

From: William Lo [mailto:williaml@xxxxxxxxxxx]
Sent: Thursday, May 14, 2015 5:02 PM
To: Marek Hajduczenia; STDS-802-3-RTPGE@xxxxxxxxxxxxxxxxx
Subject: RE: [802.3_RTPGE] Clause 45 updates

 

Hi Marek,

 

Good job cleaning this up. 

One thing I’m wondering why many of the reserved registers that are R/W got changed to RO.

i.e. 1.2304.14:12

 

Looking at existing registers in other parts of clause 45 registers that have predominantly R/W bits, the reserved bits are

also R/W and not RO. (i.e. 1.9.15:11, 3.0.9:7). 

 

I think to be consistent we should not change the R/W to RO.

 

Thanks,

William

 

From: Marek Hajduczenia [mailto:marek.hajduczenia@xxxxxxxxx]
Sent: Tuesday, May 12, 2015 8:52 AM
To: STDS-802-3-RTPGE@xxxxxxxxxxxxxxxxx
Subject: [802.3_RTPGE] Clause 45 updates

 

Dear colleagues,

 

Pete and myself went in detail through Clause 45 D1.4 version and identified a number of changes, mostly editorial, needed to align it with the style and wording from Clause 45 in 802.3, and minimize the number of comments we would be getting on Clause 45in Working Group ballot. There were many changes done (see attached PDF with diff changes) and these can be classified into the main groups of changes:

 

-          fixed incorrect editorial instructions (E)

-          removed “register” from names of registers in tables listing register names, e.g., Table 45-3. These were considered repetitions. Also, words were decapitalized (“Control Register” becomes “control”)

-          fixed names of individual registers in level 4 headings, e.g., “BASE-T1 PMA Control Register” becomes “BASE-T1 PMA control register”. In some cases, it was needed to add word “register”, and in some just drop capitalization off

-          in multiple tables for individual registers, we had “set to 0”, “set to 0s”, or some other wording  - the wording used consistently in Clause 45 is “Value always 0”. Also, respective register bits are always marked as “RO” which was aligned across all tables in Clause 45.

-          all register tables were missing footnotes with explanation of RO, RW, SC, LH, LL, etc. – these were added consistently.

-          captions in all tables describing individual bit assignment for registers were corrected to match Clause 45 style, i.e., “<REGISTER_NAME> bit definitions”

-          in multiple locations, name of the register used in descriptive text did not match the name of the register defined in heading / tables – these were aligned.

-          in multiple locations, name of PHY / PMA / PMD was missing – depending on register scope, either “BASE-T1”, or “1000BASE-T1” was added to specify what PHY / PMA / PMD we are referring to

-          in multiple level 5 headings defining individual register bits, names of fields were aligned with names used in the associated tables, e.g., in 45.2.1.130a.1, “BASE-T1” was removed to match with content of Table 45–98a. Where appropriate, capitalization was also fixed

-          in Table 45–98e, register 1.2308.15:13 was named incorrectly as “reserved”

-          in Table 45–163c, register 3.2305.5:0 was missing the word “count” in the name

-          references to correct tables were added together with the associated text in 45.2.3.50d, 45.2.3.50f, 45.2.7.14c, 45.2.7.14d, 45.2.7.14e

-          “NEXT PAGE” was changed to “Next Page” to match what is used elsewhere

 

These changes do not account for any other received comments against D1.4 (these will be considered and implemented separately), but I would like to consider them as fixes required to prepare Clause 45 for WG ballot in July. Please let me know if there are any concerns abou the proposed changes. I will be submitting a post-deadline comment for this document, and will bring this comment up for discussion at the F2F meeting to make sure that we all have a chance to review / discussion any concerns.

 

Last but not least, I wanted to thank Pete for spending a few hours of his time going over the changes and preparing Clause 45 for WG ballot.

 

Regards

 

Marek