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09/05/09 21:59
Modified:
  09/05/09 23:20
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 		 #168748 - Fastest way to fill buffer
Hi, I am making a small project with an GLCD, and I want to know if anyone knows the fastest way to clear a 1024 byte buffer (which is in external memory at location 0).

So far I have done this:

Save This Code
	clr a
	mov r0, a
	mov p2, a
	cpl a

lp1:
	movx @r0, a  ;P2 = 0
	inc p2
	movx @r0, a  ;P2 = 1
	inc p2
	movx @r0, a  ;P2 = 2
	inc p2
	movx @r0, a  ;P2 = 3
	dec r0
	movx @r0, a  ;P2 = 3
	dec p2
	movx @r0, a  ;P2 = 2
	dec p2
	movx @r0, a  ;P2 = 1
	dec p2
	movx @r0, a  ;P2 = 0
	djnz r0, lp1

 


Which ends in 1603uS (at 24MHz in a 12clocker), which is a perfect time, considering that minimum time is 1500 uS (1 movx and 1 inc/dec)

Does anybody know how to make it even faster?

Thanks,
Gonzalo

List of 11 messages in thread
TopicAuthorDate
Fastest way to fill buffer            01/01/70 00:00      
   something like this            01/01/70 00:00      
   when software hits limits...            01/01/70 00:00      
      auto-increment            01/01/70 00:00      
         Two questions ..            01/01/70 00:00      
         But Gonzallo unrolled it already isn't it?            01/01/70 00:00      
            Yes, but not with the hardware increment            01/01/70 00:00      
                be specific            01/01/70 00:00      
                  Don't forget about the Maxim/Dallas parts!            01/01/70 00:00      
            what to unroll            01/01/70 00:00      
               Well, what you CAN do ...            01/01/70 00:00      

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