Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!rutgers!mit-eddie!uw-beaver!fluke!pwv From: pwv@fluke.UUCP Newsgroups: comp.sys.m68k Subject: Re: Signetics (Philips) scc68070 CPU chip Message-ID: <2111@sputnik.COM> Date: Wed, 28-Oct-87 11:54:06 EST Article-I.D.: sputnik.2111 Posted: Wed Oct 28 11:54:06 1987 Date-Received: Sat, 31-Oct-87 06:54:40 EST References: <3240@hoptoad.uucp> Sender: news@tc.fluke.COM Organization: John Fluke Mfg. Co., Inc., Everett, WA Lines: 32 In article <3240@hoptoad.uucp> gnu@hoptoad.uucp (John Gilmore) writes: >I just looked over a preliminary data sheet for the 68070 tonight. >It's basically a 10 MHz 68000 with a crazed 'segment based' mmu, UART, >timers, DMA channel, kitchen sink, etc all on a CMOS chip in a small >plastic chip carrier. ... > >However, for some reason just about EVERY instruction runs from 1 to 15 >cycles SLOWER than the 68000! All the simple instructions run in 7 >cycles instead of 4; .... I think that you missed one very important fact, John: the 68070 uses a 2X clock scheme: Where a 68000 counts T states of a 10 MHz clock the 68070 counts it's states off a 20 MHz clock BUT uses a 10 MHz bus clock. Soooo, the 68070 actually runs FASTER than a 68000 of equivalent BUS speed. > ... I thought Signetics was licensed >to produce the 68000; why didn't they just use the old one? It wasn't >a 68020 but it was at least as fast as a 68000... CMOS. See your the first paragraph of your message. If you want to get more information from the horses mouth, so to speak, Michael Gordan Weaver (weaver@prls.UUCP) of Signetics Microprocessor Division and Junien Labrousse (junien@prls.UUCP) of Philips Research Labs have both posted info on the 68070 in this forum last May. (Junien also claims to be one of the architects.) -- Pat Vilbrandt John Fluke Mfg. Co., Inc. Everett, Washington USA UUCP: { ihnp4!uw-beaver, ucbvax!lbl-csam, allegra, ssc-vax }!fluke!pwv domain style address: pwv@tc.fluke.COM ARPA: fluke!pwv@uw-beaver.ARPA