leed@hplsla.HP.COM (Lee Darrow) (07/30/87)
Does anyone out there know the 'Best Case', 'Cache Case', and 'Worst Case' cycle counts for the MC68020 BRA instruction. I can't seem to find it in the manual. Is it me or is it the manual? Lee Darrow Hewlett Packard leed@hplsla
hunter@oakhill.UUCP (Hunter Scales) (07/30/87)
In article <5930001@hplsla.HP.COM> leed@hplsla.HP.COM (Lee Darrow) writes: > > > > Does anyone out there know the 'Best Case', 'Cache > Case', and 'Worst Case' cycle counts for the MC68020 > BRA instruction. I can't seem to find it in the > manual. > > Is it me or is it the manual? > > Lee Darrow > Hewlett Packard > leed@hplsla The "bra" instruction is listed under as Bcc (all branches take the same time, regardless of condition; bra is just a pseudonym for branch true). See section 9.2.15 Conditional Branch Instructions in the MC68020 users manual. -- Motorola Semiconductor Inc. Hunter Scales Austin, Texas {ihnp4,seismo,ctvax,gatech}!ut-sally!oakhill!hunter (I am responsible for myself and my dog and no-one else)
top@tub.UUCP (08/06/87)
>> Does anyone out there know the 'Best Case', 'Cache >> Case', and 'Worst Case' cycle counts for the MC68020 >> BRA instruction. I can't seem to find it in the >> manual. > The "bra" instruction is listed under as Bcc (all >branches take the same time, regardless of condition; >bra is just a pseudonym for branch true). >See section 9.2.15 Conditional Branch Instructions >in the MC68020 users manual. >-- >Motorola Semiconductor Inc. Hunter Scales >Austin, Texas {ihnp4,seismo,ctvax,gatech}!ut-sally!oakhill!hunter First: Nice to hear from a motorola-person. Second: Do *YOU* (or anyone else) know any possible way to code a loop *WITHOUT* any memory references, just cache-references ? I thought: x: sub.l #1, d0 bpl x serves the problem, but I still get one memory reference per loop. It seems to be the prefetch -- done every loop-cycle but thrown away... It would be nice to here any answers from you motorola-guys out there. Thanks in advance ! PS: I don't read notes (& mail) that often, so don't wonder if it may take some time discussing with me... Thomas Patzelt, Technical University of Berlin USA : ...!pyramid!tub!top (UUCP) or ...!seismo(now uunet ??)!unido!tub!top (UUCP) Europe: ...!mcvax!unido!tub!top (UUCP) BITNET/EARN top@tub.BITNET