Databook on Lite-On PNIC-II

[Donald Becker]

On Sat, 1 Apr 2000, Bill Paul wrote:

> >> I knew the chip was supposed to be compatible with Macronix's 
> >> products. So, I e-mailed Macronix and asked them for info on which 
> >> of their chips was the same as Lite-On chip. They have told me that    
> >> the 98715 is an exact match. 
> 
> Not 100% exact, but pretty close.

> > Donald Becker wrote.
> > While Macronix and Lite-On have a close relationship, the PNIC-II is *not*
> > the same as the 98715. Beyond both being loosely Tulip clones, they are not
> > even close. A quick look at the driver sections will confirm this.
> 
> I'm sorry, but this is wrong. The LC82C115 chip is very, *very* similar
> to the 98715A.

It similar mostly in the sense that they are both trying to be work-alikes
to the 21143.  Their differences from the 21143 were both driven by the
bogusness in the 21143.

> The differences are that it supports magic packet/Wake on
> LAN and has a 128-bit multicast hash table instead of a 512-bit table
> like most tulip clones.

It points out that the chips are not the same.  Macronix now owns the
Lite-On design, but the 98715 and the PNIC-II started from different bases.
At least they both were trying to copy the good Digital architecture, rather
than force an old 8390-like design into going faster.

> It has the same 21143-alike NWAY support as
> the 98715A, the same register layout (except for the new ones needed
> for the magic packet/WOL stuff) and the same rx filter programming scheme
> (except for the smaller hash table). The PNIC II is basically the 98715A
> with a few extra features (and one misfeature).

The c115 document that I have uses the MXIC logo, but in much the same way
that "Digital" was replaced by "Intel" in the 21143, without changing the
contents.  It doesn't say 98715 anywhere in the text.  I'm guessing the
98715A was the merger ("alignment") of the PNIC-II evolution with the
98715.

> > The PNIC-II datasheet is (or was at one time), proprietary. I have no
> > rights to redistribute it.
> 
> I got my copy from LinkSys when the asked me to do support for their
> new card, and they never said anything about limiting redistribution.
...
> http://www.freebsd.org/~wpaul/Macronix/PNIC_II.PDF
> http://www.freebsd.org/~wpaul/PNIC/pnic.ps.gz
> 
> The latter is the datasheet I have for the original PNIC. It's not
> terribly spectacular. These datasheets have been sitting at these
> URLs for a while.

The original PNIC datasheet evolution was amusing.  It started out as a few
quick notes, and moved to increasing detail.  All the while keeping the
Jan. 95 date.  (Uhmm, cred gap.)  You always needed a 21140 databook
around to understand what they had intended to write.

Donald Becker
Scyld Computing Corporation, becker@scyld.com

-------------------------------------------------------------------
To unsubscribe send a message body containing "unsubscribe"
to linux-tulip-request@beowulf.org