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Read-Only Author behrang moojani Posted 10-Sep-2005 10:35 GMT Toolset None	look up table behrang moojani i am trying to use code memory space to store some constants patterns. to do this, i have defined an array in code memory space as follows: unsigned char code A[]={0x00,0x3F,0x50,0x90,0x50,0x3F,0xAA}; it doesn't work at all or sometimes i get unpredicted results. but when i define the array in data memory and initialize the array as follows. can anyone help me? thanks A[1] = 0x00; A[2] = 0x3F; . A[6] = 0xAA

Read-Only Author Andy Neil Posted 10-Sep-2005 13:18 GMT Toolset None	RE: look up table Andy Neil In what way does it "not work at all?" Have you tried this in the simulator? Have you looked in the map file & verified that the code constants are being placed in a sensible location? Are you getting any errors or warnings during the build? Post the smallest complete program that illustrates the problem - and remember those 'pre' and '/pre' tags when posting code (see the 'Notes' immediately above the 'Message' window when you post).

Read-Only Author behrang moojani Posted 10-Sep-2005 18:23 GMT Toolset None	RE: look up table behrang moojani dear Andy Neil if you still read me, first of all, thanks for writing me back anyway, cause this problem is making me crazy, any way, i haven't tried it on simulator,instead i am trying this code directly on hardware each time i proramme it, the irony is that it works perfectly well when i initialize the array element by element,but it doesn't work when i try it the following way: A[] = {0x00,0x03F,0x050,0x090,0x050,0x03F}; or A[] = {0x00,0x03F,0x050,0x090,0x050,0x03F}; you have any suggestion?

Read-Only Author Dan Henry Posted 10-Sep-2005 18:29 GMT Toolset None	RE: look up table Dan Henry The array defined with initializers is initialized by the runtime startup code, whereas the other way is by explicit assignment in your program. Are you including the runtime startup in your project? http://www.keil.com/support/man/docs/c51/c51_ap_startup.htm

Read-Only Author Andy Neil Posted 10-Sep-2005 20:36 GMT Toolset None	RE: look up table Andy Neil "Are you including the runtime startup in your project?" It shouldn't be necessary to explicitly include it - if you don't explicitly include it, you should automatically get the default.

Read-Only Author Andy Neil Posted 10-Sep-2005 20:44 GMT Toolset None	RE: look up table Andy Neil "i haven't tried it on simulator, instead i am trying this code directly on hardware each time i proramme it" And you say it's driving you crazy - so don't do it! Unless you have a chip with on-chip debug - in which case, use it! IF you can reproduce the problem in the simulator, it will be much easier to debug; if you can't, it most likely means that you have a hardware fault, misconfiguration, or your interfacing is bad. "you have any suggestion?" I'm still waiting for your response to my previous questions & suggestion: Have you looked in the map file & verified that the code constants are being placed in a sensible location? Are you getting any errors or warnings during the build? Post the smallest complete program that illustrates the problem.

Read-Only Author Andy Neil Posted 10-Sep-2005 20:50 GMT Toolset None	RE: look up table Andy Neil Note that unsigned char code A[]={0x00,0x3F,0x50,0x90,0x50,0x3F,0xAA}; is not equivalent to A[1] = 0x00; A[2] = 0x3F; : A[6] = 0xAA; Your array indexes are out by one! If you are making the same mistake elsewhere in your code, you will get unexpected behaviour! (and you are probably trying to access the byte after the end of the array...!)

Read-Only Author behrang moojani Posted 11-Sep-2005 19:55 GMT Toolset None	RE: look up table behrang moojani dear Andy Neil i am so thankful to youR attention, i checked startup.A51 to see if there is any option to manipulate the enternal code memory of 8051 for initialization, and there is no such option so far as i can see, so tell me if i am making a mistake, and then, this code is perfectly working well when i am initializing the array element by element in AT89C52 internal RAM, but because of the volume of data, i have no other option except using the code space. i even translated the C51 code i had written to assembly all by hand and it worked, but because of some complexities, it's not possible to wtire the entire code in assembly, i am looking forward to hear from you, thanKs.

Read-Only Author Andrew Neil Posted 12-Sep-2005 06:49 GMT Toolset C51	RE: look up table Andrew Neil You need to find out why the initialisation in the definition isn't working. See my previous replies: * Check your 'C' array indexing; * Use the simulator.

Read-Only Author Stefan Duncanson Posted 12-Sep-2005 10:33 GMT Toolset None	RE: look up table Stefan Duncanson We cannot help you further unless you post the smallest complete program which shows the problem. Please copy and paste this from you editor - do not retype it.

Read-Only Author Benno Baumgartner Posted 19-Sep-2005 12:38 GMT Toolset C51	RE: look up table Benno Baumgartner have you ever tried to set the "code" definition in the first place. are you sure the array definition "A" is not defined elsewhere. Try out the following definition: code unsigned char MyArray[7]={0x00,0x3F,0x50,0x90,0x50,0x3F,0xAA};

Read-Only Author behrang moojani Posted 19-Sep-2005 21:38 GMT Toolset C51	RE: look up table behrang moojani thanks for your attention, and thanks foR your replay, actually there was nathing wrong with the code i had written, there was something wrong with the version of software i was using, i didn't know it was using a cracked one.

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