Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/3/84; site enmasse.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!mhuxn!mhuxr!ulysses!allegra!mit-eddie!think!harvard!talcott!panda!enmasse!frankr From: frankr@enmasse.UUCP (Franklin Reynolds) Newsgroups: net.micro.68k Subject: Re: Latest MC68020 bug list by request Message-ID: <454@enmasse.UUCP> Date: Wed, 21-Aug-85 16:17:10 EDT Article-I.D.: enmasse.454 Posted: Wed Aug 21 16:17:10 1985 Date-Received: Sat, 24-Aug-85 17:17:31 EDT References: <483@oakhill.UUCP> Reply-To: frankr@enmasse.UUCP (Franklin Reynolds) Organization: Enmasse Computer Corp., Acton, Mass. Lines: 43 In article <483@oakhill.UUCP> davet@oakhill.UUCP (Dave Trissel) writes: >The allegations are quite absurd. Here is the latest bug list for the '020 >1A45J mask which has been out for some time. This is as of August 12, 1985. > > 1) the CAS2.x instruction will not operate correctly if either of the > operand effective addresses is data register indirect (Dn). > > 2) The TAS instruction will not operate properly if either the read or write > portion of the RMC cycle is bus-errored. (We have a ten line fix for > this in the exception handler.) > > 3) The BTST (bit test) instruction when used as follows will not do the bit > test: > BTST Dn,#< > I just checked the letter I received from Motorola describing bugs in their A45J mask. Please note that my letter is dated july, not august, 1985. Anyway, the first two errors are listed but the third is nowhere to be found. In addition, six other bugs are listed. 1. LINK A7,Disp will load A7 with an undetermined value. 2. During power on RESET the RMC pin may be driven high. If bus error occurs during an arbitrated bus cycle, RMC may driven high for several clocks before being tri-stated. 3. Coprocessor primitive to evaluate EA and transfer data where the EA is immediat addressing and the size is byte passes the operand to the co- processor as a word. As such, the byte operand is passed in bit position [23 -16] rather that bit [31-24]. 4. CMP.x (A7)+,(Ax)+ may not work correctly in a virtual environment. 5. There is a problem with the RTE instruction when returning from a bus access error (bus error or address error) that may cause the porcessor to hang up. The letter goes on to describe how to write a bus exception handler that can deal with problem mentioned above. Franklin Reynolds EnMasse Computer Corp. {genrad,panda,harvard}!enmasse!frankr