From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <200007301643.RAA16451@hyperion.valhalla.net> Date: Sun, 30 Jul 2000 17:44:03 +0100 Subject: Re: Stealth port problems From: "Iain Sandoe" To: Takashi Oe CC: linuxppc-dev@lists.linuxppc.org Mime-version: 1.0 Content-type: text/plain; charset="US-ASCII" Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Sun, Jul 30, 2000, Takashi Oe wrote: > On Sun, 30 Jul 2000, Iain Sandoe wrote: > >> > Ok, this is a news to me. I'm certain that SCC on oldworld pmacs is >> > 85C30. When did the change to 85230 occur? If I remember correctly, >> > some DMA setup codes in macserial.c need to know about it if it's dealing >> > with 85230 rather than 85C30. >> >> OK - I don't know for certain - but the code refers to an "ESCC" which is >> the name of the 85230 - the 8530 should just be called "SCC". > > It's not 8530. I got an impression from Zilog's manual that ESCC refers > to both 85230 and 85C30 loosely. That manual has "Iain's all-time-award-for-the-worst-written-chip-manual" :-( > Actually, on some pages, the term was > used to refer to functionalities only available on 85230, and, on other > pages, it was used to describe something 8530 doesn't support but both > 85C30 and 85230 do. AMD's usage of the term ESCC is yet slightly > different, IIRC. > > Anyway, Apple's documentation uses the term ESCC and 85C30 > interchangeably, and I think the driver's usage of the term "ESCC" comes > from there. OK. Well, that makes things worse - rather than better (re. the original problem - if DMA is not enabled). The 8530 had only 4 bytes of RX buffer & only 2 Tx (the ESCC doubled these) - can't remember about the 85C30. Wrote drivers for the other two some years ago on a different OS (so memory might be a shade foggy). Of course, Apple has implemented the devices as a cell in an ASIC - so who knows? Iain. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/