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???
06/03/05 19:46
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 		 #94314 - Try these
Responding to: ???'s previous message
Ofir Epstein said:
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I tried the example that you gave, but the asm51 compiler says that there are two errors:

    1:	  0000	74 F4		mov a,#0F4h
    2:	  0002	78 04		MOV R0,#004h
    3:	  0004	78 00 00	CJNE A,R0,NOT_EQ
				       ^
			  @@@@@ illegal operand @@@@@

    4:				; ... .... ; R7 = 60H.
    5:	  0007	40 00		NOT_EQ: JC REQ_LOW ; IF A < R0.
					   ^
			  @@@@@ symbol not defined @@@@@

    6:				; ... .... ; R7 > 60H.
    7:				end



Hi Ofir,
What are you trying to do exactly? Comparing Accumulator with a value? or Comparing Acc with a register? You cant explicitly compare Accumulator with a register.

CJNE can take the following forms:
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              CJNE A,direct,rel
              CJNE A,#data,rel

              CJNE Rn,#data,rel
              CJNE @Ri,#data,rel


In line 2 of your above code, you are moving 04h to R0(why #004h?) If you are sure that always you will be comparing Accumulator with #04h, then use
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         CJNE A,#04h,NOT_EQ

If that is not true, if the value at R0 changes (I mean that you are going to compare the value of R0 with Accumulator), then use
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         CJNE A,00h,NOT_EQ

(Since that piece of code starts at 0000h, which is the reset vector address, and upon reset PSW will be 00h, the active bank will be bank 0. So, 00h direct address will be your current R0.)
Or if you are sure about the register bank in use, substitute the address of R0 of corresponding bank in the CJNE instruction.

About line 5, where is the lable REQ_LOW? If your assembler cant find any label mentioned in jumps and calls, similar error will occur.

Regards,
Vignesh.


List of 23 messages in thread
TopicAuthorDate
compares on the 8051.            01/01/70 00:00      
   CJNE            01/01/70 00:00      
      sorry, I forgot            01/01/70 00:00      
   compares on the 8051            01/01/70 00:00      
      Not so good...            01/01/70 00:00      
         Comparing            01/01/70 00:00      
            where is the bible?            01/01/70 00:00      
               Here it is            01/01/70 00:00      
               Compare value            01/01/70 00:00      
                  the code            01/01/70 00:00      
                     Another method            01/01/70 00:00      
                        what?            01/01/70 00:00      
                           No            01/01/70 00:00      
                              There are more errors!            01/01/70 00:00      
                                 anyone??            01/01/70 00:00      
                                 There are more errors!            01/01/70 00:00      
                                    YOU ARE GREAT!!! THANKS!!!            01/01/70 00:00      
                                       Simulator            01/01/70 00:00      
                                       search..            01/01/70 00:00      
                                          Compare tips            01/01/70 00:00      
         Try these            01/01/70 00:00      
            sensors            01/01/70 00:00      
   Macros            01/01/70 00:00      

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