1.\" $NetBSD: memc.4,v 1.3 2002/01/15 01:49:56 wiz Exp $ 2.\" 3.\" Copyright (c) 2001 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Steve C. Woodford. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.Dd July 28, 2001 38.Dt MEMC 4 mvme68k 39.Os 40.Sh NAME 41.Nm memc 42.Nd MVME162-MVME177 Memory Controller Chip 43.Sh SYNOPSIS 44.Cd "memc* at mainbus0" 45.Sh DESCRIPTION 46The 47.Nm 48devices are used on MVME162, MVME167, MVME172 and MVME177 boards 49to manage one or more DRAM modules. 50.P 51Depending on the type of DRAM module fitted, the device will 52either be a MEMC040 device or an MCECC device. The former manages 53a Parity DRAM module while the latter manages an ECC DRAM module. 54.Sh DIAGNOSTICS 55.Bl -diag -compact 56.It memc0 at mainbus0. 57This is the normal autoconfiguration message indicating that the 58Memory Controller Chip has been found and attached to the main processor 59bus. 60.It memc0: Correctable error on CPU read access to 0x12345678. 61This indicates that an MCECC memory controller detected and corrected 62a single bit error in one of the DRAM banks. There are a few variations 63on the message where "CPU" can be replaced with "Peripheral Device" 64or "Scrubber", and "read" can be substituted for "write". 65This message is followed by some more details which can help pin-point 66the error... 67.It memc0: ECC Syndrome 0x23 (DRAM Bank C, Bit#16). 68Pin-points exactly where the error occurred. 69.It memc0: Uncorrectable error on CPU read access to 0x12345678. 70Errors like this have the potential to corrupt data. As such, it is 71likely the system will panic very soon afterwards. 72.El 73.Sh SEE ALSO 74.Xr mainbus 4 75.Sh BUGS 76The 77.Nm 78driver does not yet fully support the MEMC040 (Parity) version 79of the device. 80