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???
07/09/10 14:06
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Msg Score: +4
 +4 Good Answer/Helpful		 #177191 - No need for these canned "schedulers"
Responding to: ???'s previous message
There really is no need for these pre-canned scheduler packages in most 8051 embedded systems.

What I do is design all my critical I/O to take place in either short interrupt service routines or timer dispatched state machines. I then use the mainline program to operate the connectivity algorithms that tie the I/Os together and make the embedded gadget "do its job". This mainline program is free to run any slow I/O as needed. I have built many a device in this manner even with mainline firmware running graphics LCDs and I2C peripherals and had no problems with performance. The mainline code is able to utilize ALL of the CPU band width that is not consumed by the various timer dispatched state machines and other interrupt routines. It is rare that I've had implementations where the mainline code has had less than 80-85 percent of the processor bandwidth even under the worst case conditions. And if the budget gets too close then just select an MCU with a higher clock frequency!!

Michael Karas


List of 23 messages in thread
TopicAuthorDate
co-operative scheduler            01/01/70 00:00      
   RE: This inevitably wastes processing time.            01/01/70 00:00      
      re - Separate display processor            01/01/70 00:00      
         I see (I think)            01/01/70 00:00      
            re - Separate display processor            01/01/70 00:00      
   Separate display processor?            01/01/70 00:00      
      re - Separate display processor            01/01/70 00:00      
   how can processing "waste processing time"            01/01/70 00:00      
      Answered here?            01/01/70 00:00      
      All multi-tasking with real-time requiremens suffer waste            01/01/70 00:00      
         re - Separate display processor            01/01/70 00:00      
            Parasitic newspapers?            01/01/70 00:00      
   I do not know your "Time Triggered Prioritised Cooperative S            01/01/70 00:00      
      re - Separate display processor            01/01/70 00:00      
         what does a time interval have to do with it?            01/01/70 00:00      
         TTPCS            01/01/70 00:00      
            re- TTPCS            01/01/70 00:00      
   No need for these canned "schedulers"            01/01/70 00:00      
      re - real time system            01/01/70 00:00      
         no, it does not            01/01/70 00:00      
            re- Scheduler            01/01/70 00:00      
      Timeslice timewaste            01/01/70 00:00      
         re - real time system            01/01/70 00:00      

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