Re: ASSEMBLY MOVE/CLEAR/SET/COMPARE ROUTINES

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Article #33717

#33717

From: Eric Gisin
Date: Tue, 23 Aug 1988 01:04

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In article <8808180442.AA08547@cory.Berkeley.EDU>, dillon@CORY.BERKELEY.EDU (Matt Dillon) writes:
> In an article I write:
> :copying 12 long words with movem (a0)+,regs; movem regs,(a1); add.l Rn,a1"
> : takes 242 cycles on the 68000,
> :while 12 successive "move.l (a0)+, (a1)+" takes 240 cycles.
> :(timings derived from Motorola'a 68000 manual)
> :when copying fewer words, move.l is even better.
> 
> 				* BULL SHIT *
> 
> 	The motorola manual states the following for movem.l:
> 
> 	movem M->R, long:  (An)+:   12 + 8n clock cycles
> 	movem R->M, long:  (An):     8 + 8n clock cycles
> 	add.l D0,A1:		     8      clock cycles
> 
> 	Total clocks to move 12 longwords of data from source to destination
> 	in an ascending copy is:  220 clock cycles
>  [asks where I got my information]

Third edition of the Motorola 16-bit microprocessor user's manual.
It is dated 1982. On page 203, movem r->m (long) is 8+10n cycles.
I guess my sources are obsolete.

Anyone know when this changed to 8+8n cycles?

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From: egisin@watmath.waterloo.edu (Eric Gisin)
Newsgroups: comp.sys.atari.st,comp.sys.m68k
Subject: Re: ASSEMBLY MOVE/CLEAR/SET/COMPARE ROUTINES
Message-ID: <20499@watmath.waterloo.edu>
Date: 23 Aug 88 01:04:59 GMT
References: <8808180442.AA08547@cory.Berkeley.EDU>
Organization: U of Waterloo, Ontario
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