jamie@defoe.enet.dec.com (01/10/91)
Hello! I wonder if anyone has a listing of 68000 instruction timings for the ST ? I've got a couple of books on ST internals and 68000 programming but neither of them mention instruction speeds at all. I'm trying to write some code to remove all the borders so I need to know exactly how many clock cycles each instruction takes in my code... Can anyone help ? Cheers, Jamie.
fischer-michael@cs.yale.edu (Michael Fischer) (01/10/91)
In article <18805@shlump.nac.dec.com> jamie@defoe.enet.dec.com () writes: >Hello! > >I wonder if anyone has a listing of 68000 instruction timings for the ST >? I've got a couple of books on ST internals and 68000 programming but >neither of them mention instruction speeds at all. I'm trying to write >some code to remove all the borders so I need to know exactly how many >clock cycles each instruction takes in my code... > >Can anyone help ? Sure. Get the Motorola MC68000 Microprocessor User's Manual, published by Motorola, Inc. The instruction timings take up 8 pages of an appendix (in the version of the manual that I have)! They are quite complicated and depend on the particular instruction, addressing mode and lengths of the two operands. -- ================================================== | Michael Fischer <fischer-michael@cs.yale.edu> | ==================================================
csbrod@informatik.uni-erlangen.de (Claus Brod (turo)) (01/12/91)
fischer-michael@cs.yale.edu (Michael Fischer) writes: >>I wonder if anyone has a listing of 68000 instruction timings for the ST >>? I've got a couple of books on ST internals and 68000 programming but >>neither of them mention instruction speeds at all. I'm trying to write >>some code to remove all the borders so I need to know exactly how many >>clock cycles each instruction takes in my code... Be sure to include in your calculations that, on the ST, some instructions may take longer than what Motorola tells you. This is due to the fact that there are some 6-cycle instructions, and the ST bus is shared between processor and shifter on a 4-cycle-basis. Thus, these instructions can effectively take 8 cycles instead of 6! (This applies to any instruction which has an instruction time which is not a multiple of 4.) ---------------------------------------------------------------------- Claus Brod, Am Felsenkeller 2, Things. Take. Time. D-8772 Marktheidenfeld, West Germany (Piet Hein) csbrod@medusa.informatik.uni-erlangen.de ----------------------------------------------------------------------
Roger.Sheppard@bbs.actrix.gen.nz (01/15/91)
In article <18805@shlump.nac.dec.com> jamie@defoe.enet.dec.com () writes: > Hello! > > I wonder if anyone has a listing of 68000 instruction timings for the ST > ? I've got a couple of books on ST internals and 68000 programming but > neither of them mention instruction speeds at all. I'm trying to write > some code to remove all the borders so I need to know exactly how many > clock cycles each instruction takes in my code... > > Can anyone help ? > > Cheers, > > > Jamie. I do have a Manual called Programmmer's Reference Manual M68000UM/AD , Prentice-Hall, ISBN 0-13-541491-1, there is also a Pocket book version of this manual used to come with the HighSoft DevpacST also I have a Programming card, MC68000(AC1), all this was from the Motorola agent here in Wellington NZ,, ..VSI.. -- Roger W. Sheppard 85 Donovan Rd, Kapiti New Zealand...