Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 8/7/84; site ucbvax.ARPA Path: utzoo!watmath!clyde!burl!ulysses!ucbvax!info-vax From: info-vax@ucbvax.ARPA Newsgroups: fa.info-vax Subject: Re: MachineChecks Message-ID: <2740@ucbvax.ARPA> Date: Mon, 22-Oct-84 11:34:05 EDT Article-I.D.: ucbvax.2740 Posted: Mon Oct 22 11:34:05 1984 Date-Received: Tue, 23-Oct-84 02:05:53 EDT Sender: daemon@ucbvax.ARPA Organization: University of California at Berkeley Lines: 93 From: NEWMAN%SAV@LLL-MFE.ARPA Ron: What follows is an example from a machine check we had here at SAIC Oak Ridge just recently. When we got it I went looking through the hardware reference manual and the Arichetecture handbook to find out what the stack looked like. There is no documentation other than the fiche. This is a copy of what I sent out to some of the other people in our company. Hope this helps. gkn ------------------------------------------ Arpa: Newman%SAV@LLL-MFE.Arpa USPS: Gerard K. Newman Science Applications International 800 Oak Ridge Turnpike Oak Ridge, TN 37830 AT&T: (615) 482-9031 -------------------------------------------------------------------------------- From: GKN 15-OCT-1984 16:21 Subj: Machine checks on the 11/780 Having just had a machine check crash and discovering that the documentation for the contents of the machine check logout stack is virtually non-existant I thought I'd share with you what the stack looks like and a little about what kinds of things cause a machine check. All of this information is 11/780 specific; I havn't looked at the machine check exception handlers for the 11/730 or 11/750. I suspect (though I don't know for sure) that this information is valid for the 11/785 also. Stack format: @SP: 00000028 Number of bytes pushed onto the stack 008800F6 Machine check summary parameter 00010204 CPU error status 0000025B Trapped micro PC 800813E7 Virtual address at fault time F4001D4B CPU "D" register 00000A01 Translation buffer status register 0 00000000 Translation buffer status register 1 00000000 Physical address causing SBI timeout 00001533 Cache parity error status 00004000 SBI error status 800054CE PC of instruction causing machine check 00C70000 PSL at fault time These parameters are actually taken from our recent machine check. We're most interested in the machine check summary paramter, the second longword on the stack. As far as I can tell, only the low order two bytes are significant. The low order byte contains the fault type in the low order 4 bits; The high order 4 bits seem to be 1111 always. The next byte contains the 'timeout pending flag', whatever that is. The fault type codes are: 0 - CPU timeout/SBI error confirmation 1 - Control store parity error 2 - Translation buffer parity error 3 - Cache parity error 4 - Not used 5 - Read data substitute error 6 - 'Microcode can't get here' error 7 - Not used 8 - Not used 9 - Not used A - IB detected translation buffer parity error B - Not used C - IB detected memory error D - IB detected CPU timeout or SBI error confirmation E - Not used F - IB detected cache problem As you can see, we just had a 'microcode can't get here' error, which gives me one of those "warm fuzzy" feelings. Anyway, the next time you get a machine check I hope this info is of some use. gkn