Holtek Chip HT46R47 Programming

Discussion in 'General Electronics Chat' started by spanish fly, Nov 4, 2013.

  1. spanish fly

    Thread Starter New Member

    Apr 27, 2010
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    Hi,
    Sorry but I'm a bit of a novice to electronics, but could someone please advise me how easy it would be to program a blank chip?
    The chip is a Holtek HT46R47, would it be more convenient to use a different make? I choose Holtek as that was the type removed from the board although the original was in a SOP package.

    Any help would be appreciated thank you.
     
  2. eyesee

    Member

    Oct 19, 2013
    33
    3
    Many of the Holtek microcontrollers are One-Time Programmable (OTP) meaning that once you have programmed them once, they cannot be programmed (written to) again. This includes the HT46R47 that you mentioned.

    The Holtek MCUs are intended for production applications where the code has already been debugged and tested. This is not a good starting point for a beginner to microcontroller programming.

    Have a look at PIC, Atmel or MSP430.
     
  3. spanish fly

    Thread Starter New Member

    Apr 27, 2010
    11
    0
    Thanks for your response to my problem, Ive tried to find the PIC alternative but can't seem to convert away from Holtek. Is it not possible to use a pre programmed chip? or would that mean redesigning the board.
     
  4. eyesee

    Member

    Oct 19, 2013
    33
    3
    Can you provide more information on what the board does and the pin connections to the microcontroller?

    You can use the Holtek, but if you are new and developing code, you'll be disposing of many of the ICs before you perfect your design.
     
  5. MrChips

    Moderator

    Oct 2, 2009
    12,452
    3,371
    OTP mcu are almost a thing of the past and have been replaced with mcu containing flash memory.

    I used OTP mcu chips for many years and developed a technique that allowed me to test, debug and patch the code thus avoiding having to throw away hundreds (or thousands) of chips.
     
  6. eyesee

    Member

    Oct 19, 2013
    33
    3
    I wouldn't say they are thing of the past. The Holtek parts are fairly new in comparison to other microcontrollers.

    The advantage of OTP microcontrollers is when manufacturing high volumes and the code will never need to be changed.
     
  7. spanish fly

    Thread Starter New Member

    Apr 27, 2010
    11
    0
    Thanks again for your help, the board is part of a golf trolley board, I'll make a circuit diagram and post later.
    The original was in a sop package this in a DIP.
    The main reason for changing the chip was when starting from stop the motor takes a while to get up to speed unless the pot is turned off then on again.
     
  8. eyesee

    Member

    Oct 19, 2013
    33
    3
    Do you have a method of extracting the existing program code from the microcontroller or have you probed the I/O lines to obtain a timing diagram?

    Otherwise, if the microcontroller code has been locked, you will need to write a program from scratch.
     
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  9. spanish fly

    Thread Starter New Member

    Apr 27, 2010
    11
    0
    No im sorry i have no way of accessing the old chip, But some information taken from the datasheet shows a diagram that could be what you are asking about a program code, other info from the data sheet is that it has 13bidiretional I/O lines, watchdog timer etc. is it possible for you to access the Holtek site to gain all the info.
    I did download the HT-IDE 3000 users guide from Holtek this could help you, but its all a bit over my head, it even shows the hardware required. Thanks
     
  10. eyesee

    Member

    Oct 19, 2013
    33
    3
    The program code will be specific to the application and the manufacturer of your equipment would have written custom code for that microcontroller.

    You cannot obtain the code from the datasheet or any other resources from Holtek.

    There may be ways others have tried to extract code from pre-programmed Holtek OTP microcontrollers but since it's surface mounted onto the board, it might be tricky probing lines. Try searching online.
     
  11. spanish fly

    Thread Starter New Member

    Apr 27, 2010
    11
    0
    I guess i'll just have to thank you for all your help and suggestions, but maybe we've hit a dead end, I don't know the manufacture of the machine just that its Chinese built. there are some markings on the board I can try and match on the net.
    The old chip was surface mounted but the new chip is in a DIP package although maybe it makes no difference.
    The only thing I could do is compile a circuit diagram if it would help
     
  12. eyesee

    Member

    Oct 19, 2013
    33
    3
    The only options you have are to try and interrogate the code from the existing microcontroller - this may or may not be possible and you will need to search online to see if others have managed to do this.

    Or to look at the circuit and devise your own code for a microcontroller.
     
  13. spanish fly

    Thread Starter New Member

    Apr 27, 2010
    11
    0
    Thanks
    Is it possible to program a chip or purchase a suitable chip if I was able to compile a circuit diagram.
    Since my last post I think Ive managed to find the firm that designed this board, Ive emailed them to see if they would give me some info. The company is ITL and based in Canada.
    The number on the board is ITL21909.
     
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