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David Prentice
10/28/11 05:41
Read: 400 times
Wormshill
England


 
#184406 - Simulate or use Logic Analyser
Responding to: Richard Erlacher's previous message
A Simulator will count your cycles for you. And get it correctly.

As far as I know, there are no 8051s that use caches. Each 8051 instruction is documented for its behaviour.

Most bottlenecks are due to frequent calls of short pieces of code. You simply hand-craft these sequences while leaving the other 99.5% of code in HLL. Let's face it, the 8051 is simple to write ASM for.

I am lazy so I get the Simulator to do the cycle counting. I sometimes use an 8051 timer or a Logic Analyser.

All the same, most efficiency is gained by improvements in the algorithm rather than the low level ASM code. As Per has noted, the actual translation of P1.4 = 0 is going to be the same.

Of course, you will get the best performance from a perfectly designed ASM program. Very few applications are that time critical. If your clients have few boards, your development time is very significant.

I am sure that you can knock out perfect ASM faster and more reliably than others can use a HLL. This is due to your experience. At your age, I expect that PDIP-40 8051 chips will see you through. A young student would better spend her time learning how to use MCUs and tools that have a realistic future.

Incidentally, when you meet your bus or jealous husband, will your clients really be able to maintain your ASM code? Or even find another expert?

David.

List of 53 messages in thread
TopicAuthorDate
Linking C programs with Keil evaluation      David Prentice      09/06/11 11:02      
   Eval Tools.      Michael Karas      09/06/11 11:15      
      That makes sense      David Prentice      09/06/11 12:11      
         It's not that much more useable      Richard Erlacher      10/25/11 18:44      
            Work-around for evaluation version limitations?      Per Westermark      10/25/11 23:50      
            Marked -1      Michael Karas      10/26/11 06:26      
               I'm not so sure you're right here ...      Richard Erlacher      10/26/11 07:55      
                  Irrelevant if people have ideas - should they be debated?      Per Westermark      10/26/11 08:19      
                     There's a reason I haven't done it ...      Richard Erlacher      10/26/11 10:36      
                        Would not represent a valid evaluation      Per Westermark      10/27/11 02:00      
                           Wait a minute ... You've got this wrong ...      Richard Erlacher      10/27/11 09:57      
                     One question      Richard Erlacher      10/26/11 12:43      
                        What about the guy who simply wants to evaluate the product?      Andy Neil      10/26/11 14:05      
                           sometimes coding situations and requirements differ      Richard Erlacher      10/26/11 18:57      
                        How would you like it?      Andy Neil      10/26/11 14:13      
                           That's not what I'm asking them to do      Richard Erlacher      10/26/11 19:17      
                              A message from the OP.      David Prentice      10/27/11 03:55      
                                 I don't supply the compiler ...      Richard Erlacher      10/27/11 10:08      
                        Wrong view on evaluation tools      Per Westermark      10/27/11 03:32      
                           as I've said before, where you sit determines what you see      Richard Erlacher      10/27/11 10:47      
                              Still failing to recognize reason for hole in code map      Per Westermark      10/27/11 12:33      
                                 You missed my point again      Richard Erlacher      10/27/11 15:35      
                                    Simulate or use Logic Analyser      David Prentice      10/28/11 05:41      
                                       ramblings      Erik Malund      10/28/11 07:51      
                                       Using evaluation software and hardware      Richard Erlacher      10/28/11 09:44      
                                          The above would be true if....      Erik Malund      10/28/11 10:24      
                                             You don't seriously believe that, do you?      Richard Erlacher      10/28/11 18:54      
                                                A thief is a thief        Per Westermark      10/29/11 07:01      
                                                   Indeed...        Michael Karas      10/29/11 09:47      
                                                   FIrst of all, I don't advocate theivery      Richard Erlacher      10/29/11 14:46      
                                                      and more mumbo jumbo in the reply      Erik Malund      10/29/11 15:47      
                                                      Can _you_ not read debugger output?      Per Westermark      10/29/11 17:39      
                                          8255      Andy Peters      10/28/11 13:26      
                                             Yes, but they're still shipped on some 805x trainer boards      Richard Erlacher      10/28/11 18:42      
                                             Just sayin'      Michael Karas      10/29/11 05:50      
                  Square Wheels for the Car      Michael Karas      10/26/11 10:06      
                     I disagree ... not that that should surprise anyone      Richard Erlacher      10/26/11 10:54      
                        eval and evaluation      Erik Malund      10/26/11 11:25      
                           Yes, if only they were useful ...      Richard Erlacher      10/26/11 12:31      
      Also "LPC900 Studio"      Andy Neil      09/06/11 12:32      
         They all seem crippled      David Prentice      09/06/11 14:22      
            comments      Erik Malund      09/06/11 16:17      
            They all seem crippled      Andy Neil      09/06/11 16:22      
               Yes ... SDCC ... the obvious solution      Richard Erlacher      09/08/11 08:30      
                  what's obvious about it      Erik Malund      09/08/11 09:00      
                     Why not?      Andy Neil      09/08/11 10:48      
                        reasons      Erik Malund      09/08/11 10:59      
                           Unfortunately      Andy Neil      09/08/11 14:13      
                              re Keil      Erik Malund      09/09/11 07:13      
                                 15 years ago?      Maarten Brock      09/09/11 09:28      
                                    OK, maybe not      Erik Malund      09/09/11 09:48      
            reasonable price      Erik Malund      09/07/11 03:41      
            raisonance is 4k with no code offset      Marshall Brown      10/25/11 13:59      

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