Path: chuka.playstation.co.uk!news From: gil@snsys.com (Gil Jaysmith) Newsgroups: scea.yaroze.programming.codewarrior Subject: Re: System memory Date: Wed, 13 Aug 1997 10:31:10 GMT Organization: SN Systems Lines: 26 Message-ID: <5ss22b$d577@chuka.playstation.co.uk> References: <01bc957d$ffb78880$9fbf43ce@wkwerner> <33d63ee2.2608036@news.scea.sony.com> <01bca2b9$a16f32c0$69bf43ce@wkwerner> <33E9982D.54A636C9@micronetics.com> <5snuct$dp61@scea> <01bca6a7$43e59580$adbf43ce@wkwerner> Reply-To: gil@snsys.com NNTP-Posting-Host: gil.snsys.com X-Newsreader: Forte Free Agent 1.0.82 "Wayne K. Werner" wrote: >Another option is what is generally refered to as a watchpoint. >Watchpoints are like breakpoints, however, instead of stopping execution >when a specific line of code is reached, execution is stopped when a >particular memory address is writen. Watchpoints put you right to the line >of code causing the memory write in question. I am unaware of whether >watchpoints are supported by CW. Unless they are supported by the >hardware, as well as the debugger, they cause MAJOR hits to the speed of >the code under the debugger. Often that is acceptable, especialy when >tracking down a nasty memory corruption problem. FYI: The PSX supports the WatchHi and WatchLo registers (R18 and R19 in the system coprocessor I think) which can be set to provide a Watch exception on certain types of access to an address (I seem to remember reading somewhere that it actually triggers on the eight-byte section surrounding that byte, but whatever). It also has a sneaky way of watching ranges of memory using R8 and R3 to specify a power of two as the size of the range to watch and the start address of the range (which must be aligned with respect to the range's size, so a 64K range can only be watched with a 64K alignment, and so forth). Gil Jaysmith SN Systems Software Ltd, makers of Psy-Q... http://www.snsys.com Disclaimer: What I say when I post here represents me, not my employers.