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Richard Erlacher
11/25/12 22:33
Read: 954 times
Denver, Co
USA


 
#188899 - You have to know hidden details about the simulator
Responding to: Robert Bowen's previous message
If the simulator doesn't account for each clock cycle in the UART and keep track of the precise timing between the various registers involved, ranging from the data register to the interrupt flag, it's not really a complete simulator. If it doesn't "know" how the chip in question operates, down to the tiniest detail, or, at least, the tiniest detail knowable from the information the manufacturer will give out, then it can't simulate them properly. Since several manufacturers of 805x's have deviated from the original Intel model, to greater or lesser extent and for reasons ranging from using fewer oscillator periods per machine cycle to adding operational features not incorporated in Intel's design, it's unlikely a simulator applied to several different variations of the 805x will yield results identical to the UART in the chip under examination.

Having spent many hours with 'scope, logic analyzer, and prototype, I'm persuaded that one shouldn't let perfection be the enemy of adequate. In most cases, the simulator is "good enough" for some things, though it's necessary to know in advance for which things it is not adequate. I've spent frustrating hours trying to figure out the synchronization details between the UART in the Maxim/Dallas DS89C4x0's, which the manufacturer wouldn't give me, because I wanted to know the timings that resulted in the various addressing modes to external memory. The result was that I switched to an external serial port implemented in programmable logic rather than guessing at what happened inside the MCU.

Having written and used scores of simulation programs I know that they're, at best, an approximation. That means that the best I can expect, from a simulator I didn't write, is that the information about unknown details is a guess. The user has to decide whether that guess is "close enough."

RE


List of 39 messages in thread
TopicAuthorDate
SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/19/12 06:04      
   I gave up long ago      Erik Malund      11/19/12 07:57      
      SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/19/12 15:12      
         Silabs IDE      Hal Albach      11/19/12 18:06      
            SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/19/12 18:57      
               Silabs IDE      Hal Albach      11/20/12 06:26      
                  SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/20/12 07:39      
                     why did you not say so      Erik Malund      11/20/12 07:48      
                        SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/20/12 08:07      
                           IDE - Silabs or Keil?      Hal Albach      11/20/12 18:15      
                              SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/20/12 19:09      
                                 so would I, but      Erik Malund      11/20/12 20:24      
                                    SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/21/12 07:05      
                                       nope      Erik Malund      11/21/12 08:44      
                                          8 Bit micro - Kernal      Robert Bowen      11/22/12 05:59      
                     but hardware is easy to get ?      Jim Granville      11/21/12 20:26      
                        SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/22/12 05:51      
                           I do not have it here, but      Erik Malund      11/22/12 08:09      
                              SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/22/12 08:58      
                                 SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/22/12 09:23      
                                    I know none that show that directly      Erik Malund      11/22/12 16:53      
                                       Keil IDE Screen shots      Robert Bowen      11/22/12 18:52      
                                          what is missing?      Erik Malund      11/22/12 19:47      
                                             SiLabs - C8051F020 - Keil IDE      Robert Bowen      11/24/12 06:52      
                                                why?      Erik Malund      11/24/12 08:27      
                                                   Why Simulator      Robert Bowen      11/24/12 14:17      
                                                      simulators      Mahmood Elnasser      11/25/12 07:02      
                                                      simulators      Mahmood Elnasser      11/25/12 07:02      
                                                         Simulator      Robert Bowen      11/25/12 11:00      
                                                            funny      Erik Malund      11/25/12 12:16      
                                                               Simulators      Robert Bowen      11/25/12 14:48      
                                                      neither of this is simulation      Erik Malund      11/25/12 12:11      
                                                         Simulator      Robert Bowen      11/25/12 14:51      
                                                            if I show you the timetable ...      Erik Malund      11/25/12 15:39      
                                                               Simulating      Robert Bowen      11/25/12 15:55      
                                                                  You have to know hidden details about the simulator      Richard Erlacher      11/25/12 22:33      
                                                                     Simulator      Robert Bowen      11/26/12 06:12      
                                                                        two aswers and a question      Erik Malund      11/26/12 07:38      
                                                                           Great suggestions, Eric....      Robert Bowen      11/26/12 08:46      

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