Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
???
12/02/07 16:54
Read: times


 		 #147730 - you need to read "the bible"
Responding to: ???'s previous message
You have to push all the registers You use in any interrupt unless You want to get a real mess around.
You do NOT need to push registers. Using the '51 in many ways defeat "common wisdom"

You need to read "the bible" and get familiar with thye chip, if you plan to use it.

Thus using table lookups, and that IS costly on C, is to be avoided during interrupts.
no, as I state3d it will cost you "two lousy microseconds" NO MORE THAN THAT. And, if I recall the VERSA is a 40 MHz 6 clocker so the total will be less than 300 nanoseconds.

Erik

here are the links to "the bible"
Chapter 1 - 80C51 Family Architecture:
http://www.nxp.com/acrobat_d...ARCH_1.pdf

Chapter 2 - 80C51 Family Programmer’s Guide and Instruction Set:
http://www.nxp.com/acrobat_d...UIDE_1.pdf

Chapter 3 - 80C51 Family Hardware Description:
http://www.nxp.com/acrobat_d...WARE_1.pdf



List of 25 messages in thread
TopicAuthorDate
how to use buffer or stack to store digits            01/01/70 00:00      
   many question            01/01/70 00:00      
   Stack            01/01/70 00:00      
   use register as a pointer to a table            01/01/70 00:00      
      How many segments?            01/01/70 00:00      
         you seldom need to use both ...            01/01/70 00:00      
            Not as DP, but...            01/01/70 00:00      
               sorry ... double post            01/01/70 00:00      
               Why would you want those?            01/01/70 00:00      
                  example            01/01/70 00:00      
      Timer interrupt and segments in RAM            01/01/70 00:00      
         many words about two lousy microseconds            01/01/70 00:00      
            Lousy microseconds            01/01/70 00:00      
               Wholehardely agree            01/01/70 00:00      
                  Burning stack bytes            01/01/70 00:00      
                     you need to read "the bible"            01/01/70 00:00      
                        Not entirely true            01/01/70 00:00      
                     Table lookup in 'C'            01/01/70 00:00      
                        Why tables can be costly on C            01/01/70 00:00      
                           Well, If you abuse the tools...            01/01/70 00:00      
                           if we consider this off topic, you may be correct            01/01/70 00:00      
                              Not even then?            01/01/70 00:00      
                                 Another thread, please            01/01/70 00:00      
                                    And the new thread is...            01/01/70 00:00      
   Example on driving 7-segment displays            01/01/70 00:00      

Back to Subject List