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Xref: sserve comp.sys.ibm.pc.hardware:34285 comp.unix.bsd:7041 Newsgroups: comp.sys.ibm.pc.hardware,comp.unix.bsd Path: sserve!manuel.anu.edu.au!munnari.oz.au!spool.mu.edu!yale.edu!ira.uka.de!math.fu-berlin.de!informatik.tu-muenchen.de!roell From: roell@informatik.tu-muenchen.de (Thomas Roell) Subject: Re: Question on Diamond Clock Synthesizer In-Reply-To: kenny@osf.org's message of Mon, 19 Oct 1992 15:14:09 GMT References: <1b7tmgINNi06@agate.berkeley.edu> <1992Oct19.082420.16353@Informatik.TU-Muenchen.DE> <1992Oct19.151409.24581@osf.org> Sender: news@Informatik.TU-Muenchen.DE (USENET Newssystem) Organization: Inst. fuer Informatik, Technische Univ. Muenchen, Germany Date: Sat, 24 Oct 1992 16:52:30 GMT Message-ID: <1992Oct24.165230.18817@Informatik.TU-Muenchen.DE> Lines: 47 >Yeah, like maybe CLK/1???? No, and that's the keypoint. Let's take another PLL where you can get the databook from to see how it works, the SC11410. Note that this one is NOT the Diamond PLL, and this one is quite different, altought the fundamentals are the same. What you basically have is a input frequency of 14.318 MHz. Internally there is ONE multiplier, and ONE divider. To stablize the output, there is a POST scaler after an internal frequency has been generated. The formula is like: fout = ((fin * M) / N) / P; M = 1 .. 127 N = 1 .. 127 P = 1, 2, 4, 8 The wide range for N & M is needed to have a good frequency resolution. There are also some considerations about prime numbers, scaling and if a pll has multiple circuts, about influence. The highest frequency you could get from this PLL would be: 1818 MHz, which is certainly above the chips spec. Hope you guys now understand the danger here. One some others it's even worse. You have to set additional parameters (depending on your target frequency). If you don't programm the right ones, you PLL might blow up. >ONCE MORE- explain to me exactly how programming a divider value into a >chip WILL BLOW IT!!! As explained above, no simple divider. >Either give me a full technical explanation, or quit talking shit! How much >*is* Diamond paying you? Actually, nothing. Althought I own some of their boards ... Hope that makes you understand, why this might be a danger for dumb hacker like you seem to be .... - Thomas -- ------------------------------------------------------------------------------- Das Reh springt hoch, e-mail: roell@sgcs.com das Reh springt weit, #include <sys/pizza.h> was soll es tun, es hat ja Zeit ...