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Michael Karas
06/20/10 10:20
Read: 776 times
Beaverton Or
USA


 
#176785 - Do not get focused on one operation...
Responding to: Richard Erlacher's previous message
The better MCU for any real application is going to be a tradeoff. There will be parts of the application where bit manipulation of a port but could be more efficient using an 8051 type instruction and access method. And then you will have the part of the algorithm where computing a 32-bit integer value will be much more efficient with a ColdFire or ARM MCU. Since one generally has to choose one over the other you pick the MCU that offers the best behavior for the most intense portions of the application algorithm.

It has been my experience however that sometimes a 32-bit architecture MCU may still offer better performance than an 8-bit MCU for bitwise access because the clocking rate of the MCU is way higher than the older 8-bit unit. I had a case where an 80MHz ColdFire 32-bit MCU used a BSET and BCLR macro set that I created that implemented parallel access instructions with AND and OR instructions. I was able to bit-bang port I/O at rates equivalent to what was achievable on a 22.1184 MHz 8051 8-bit MCU. Using that MCU I also had far superior performance for implementing 32-bit math for both integers and floats.

Michael Karas


List of 104 messages in thread
TopicAuthorDate
So What Is An 8051/2 Good For?      Andy Neil      06/17/10 16:35      
   thoughts      Erik Malund      06/18/10 04:36      
      The Future of the 805x      Joseph Hebert      06/18/10 08:40      
         PARC      Rob Klein      06/18/10 09:01      
            Bigger Hammers      Joseph Hebert      06/18/10 09:37      
               re: Bigger Hammers      Rob Klein      06/18/10 10:59      
               The opposite problem seems more common here!      Andy Neil      06/18/10 15:50      
         Would Toyota have had the problem if ...      Erik Malund      06/18/10 09:31      
            Toyota: Case in point      Joseph Hebert      06/18/10 09:46      
            RE: Toyota      Andy Neil      06/18/10 10:17      
               It was a mechanical fix ...      Richard Erlacher      06/18/10 22:37      
            Parallel Processing      Justin Fontes      06/18/10 10:35      
               Sometimes the practical reality is of little consequence      Richard Erlacher      06/18/10 22:45      
                  Totally Agree, but I was looking for a magic bullet      Justin Fontes      06/18/10 23:09      
                  RE: "outperform"      Andy Neil      06/19/10 01:10      
                     There are some operations ...      Richard Erlacher      06/19/10 06:19      
                        rephrased      Erik Malund      06/19/10 06:44      
                        Now, you are extrapolating      Per Westermark      06/19/10 06:44      
                           good points, but      Erik Malund      06/19/10 07:12      
                              How many 8051 chips uses 0.13u?      Per Westermark      06/19/10 08:57      
                                 not yet      Erik Malund      06/19/10 13:05      
                           not exactly ...      Richard Erlacher      06/20/10 09:39      
                              Do not get focused on one operation...      Michael Karas      06/20/10 10:20      
                              any 8-bit instruction can exist in a 32-bit processor      Per Westermark      06/20/10 12:14      
                                 Yes, but does it?      Richard Erlacher      06/22/10 07:54      
                                    So have you looked at any other processors?      Per Westermark      06/22/10 09:37      
                                       not a point of disagreement, but you missed it anyway      Richard Erlacher      06/22/10 22:50      
                                          A good point      Justin Fontes      06/22/10 23:10      
                                             beg to differ      Michael Karas      06/22/10 23:23      
                                             Disagree entirely!      Andy Neil      06/23/10 00:45      
                                          Yes, auto-increment/decrement is standard and not "feature"      Per Westermark      06/23/10 00:29      
                                             What I wanted to point out ...      Richard Erlacher      06/23/10 06:07      
                                                Same same all the time. no "one size fits".      Per Westermark      06/23/10 07:46      
                                                   and the most important point is (drumroll) ....      Erik Malund      06/23/10 09:49      
                                                Comparing Apples to Oranges      Andy Neil      06/23/10 08:03      
                                          Prices are comparable      Andy Neil      06/23/10 01:00      
               Parallel processing        Oliver Sedlacek      06/22/10 02:40      
                  Sweeping generalisation!      Andy Neil      06/22/10 03:22      
                     Not a magic silver bullit      Per Westermark      06/22/10 04:20      
                        Fond memories      Oliver Sedlacek      06/22/10 07:58      
                        A magic bullet      Justin Fontes      06/22/10 10:17      
                           Most concepts already exists in the wild      Per Westermark      06/22/10 11:31      
                           Another generalisation        Andy Neil      06/22/10 14:43      
                           Speed vs latency      Oliver Sedlacek      06/22/10 14:47      
                              Why 8051?      Andy Neil      06/22/10 15:08      
                                 Isn't it obvious?      Justin Fontes      06/22/10 23:17      
                                    ARM simpler than 8051      Oliver Sedlacek      06/23/10 00:21      
                                       Generalisation      Andy Neil      06/23/10 01:34      
                                          ARM 'MCUs' have their limitations too!      Valentin Angelovski      06/24/10 07:52      
                                             You normally engineer with a backup plan      Per Westermark      06/24/10 08:20      
                                    No, it's not!      Andy Neil      06/23/10 01:27      
                                       Im just trying to provide an argument      Justin Fontes      06/23/10 10:33      
                                          x bits are just one parameter among many      Per Westermark      06/23/10 11:27      
                                             Avoiding the issue      Justin Fontes      06/23/10 21:09      
                                                Avoiding what issue?      Per Westermark      06/24/10 03:10      
                                          They say it because it's true!      Andy Neil      06/24/10 00:59      
                                          RE: ARM is not the only 32-bitter      Andy Neil      06/24/10 01:15      
                                    Please don'g generalize      Per Westermark      06/23/10 01:28      
                                 Heterogenous multiprocessing widespread      Oliver Sedlacek      06/23/10 00:17      
                  Re: Multicore 8051      Valentin Angelovski      06/24/10 06:48      
                     ALU chaining      Oliver Sedlacek      06/24/10 06:57      
   Well... maybe      Jez Smith      06/18/10 14:47      
      A Linear Accelerator?      Joseph Hebert      06/18/10 15:28      
         Its one of these      Jez Smith      06/18/10 15:51      
      please, repeat      Stefan KAnev      06/19/10 04:56      
         All I was saying was      Jez Smith      06/19/10 10:39      
   So what the '51 are good for...      Jan Waclawek      06/21/10 13:54      
      Not terribly helpful      Andy Neil      06/21/10 14:46      
         Always up to the developers      Per Westermark      06/21/10 15:24      
            RE: The manufacturers tells us...      Andy Neil      06/21/10 15:30      
               Sales - "may be used for" presented as "recommended"      Per Westermark      06/21/10 16:41      
               pretty hot, low-power and small      Maarten Brock      06/22/10 15:17      
                  Automotive...      Andy Neil      06/22/10 15:26      
         but answers your original question (at least the one...      Jan Waclawek      06/22/10 10:19      
         MCS51 still rocking !!!      Kiran V. Sutar      06/23/10 05:14      
            Scale      Andy Neil      06/23/10 06:09      
            Missing the point      Andy Neil      06/23/10 06:21      
               Impossible to generalize into fields      Per Westermark      06/23/10 08:09      
                  An appropriate generalisation...      Andy Neil      06/23/10 10:20      
               You are right..Andy Neil      Kiran V. Sutar      06/24/10 05:27      
                  Cheers!      Andy Neil      06/24/10 05:43      
                     No..only AT89C52 can be used      Kiran V. Sutar      06/24/10 05:56      
                        why do you insist on Atmel?      Erik Malund      06/24/10 06:05      
                        what a strange post      Erik Malund      06/24/10 06:09      
                        Tools?      Andy Neil      06/24/10 07:12      
                           Multiple manufactuers with (almost) identical chips      Per Westermark      06/24/10 07:48      
                              Getting better      Andy Neil      06/24/10 08:52      
                                 Unified interrupt controller is really great      Per Westermark      06/24/10 09:28      
                           Yes, even with free tools for PIC/AVR      Kiran V. Sutar      06/24/10 08:38      
                              I mean no offense, but ...      Richard Erlacher      06/26/10 09:59      
                              Similar difficulties coming to 8051/2?      Andy Neil      06/26/10 10:28      
                                 Same same      Per Westermark      06/26/10 11:18      
                  Is it your purchase price or why so sure AVR or PIC are off?      Per Westermark      06/24/10 05:55      
                     Answer to Per and Erik...      Kiran V. Sutar      06/24/10 06:38      
                  Living in the past      John D. Maniraj      06/24/10 09:44      
                     Thanks John D. Maniraj      Kiran V. Sutar      06/25/10 03:54      
                     locking      Erik Malund      06/25/10 07:20      
                        RE: Locking      Andy Neil      06/25/10 07:32      
                        Agreed, but      John D. Maniraj      06/25/10 11:00      
                           fairly easy      Erik Malund      06/25/10 11:53      
      Don't forget consumer devices      David Good      06/24/10 13:45      
         A perfect application      David Good      06/25/10 10:49      
   8051 vs ARM      Valentin Angelovski      06/24/10 08:34      
   just thought of one case      Erik Malund      06/24/10 12:32      

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