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far malloc

Does anyone know if it is possible to malloc HDATA (far memory) rather than having to use XDATA on a Dallas 390 in continous mode?

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  • Stefan

    We have built a relative complex system into the DS80C390, I expect more complex than most '51 systems, and much more complex than Intel's original intention for this type of microcontroller. We did this solely to save money, as this processor had nearly all features we needed and we had some experience of the DS87C520. It has proved to be more than quick enough for our purposes.

    I originally wrote this query a year or so ago and we have since got around the issue. Anyway here was the original problem.

    In a previous embedded system we had some code that created a number of menus based on a constant array, varying the amount of memory needed for each menu. This memory was malloc'ed at switch on. We intended to port this to this new system with as little changes as possible, as the system was relatively complex and worked. The malloc'ing was just done for convenience so that we did not need to keep extending the array when a menu item was added. This previous system also had a vast amount of memory (1MB).

    As we could not seam to use the keil malloc we rewrote the code so that it used a large array that was compiled in and then allocated to the menu items at startup, and checks to see if text file exceeds the array.

    I expect there are other way of achieving the same thing but it works and is quick enough so ….

    Anyway thanks for the help

    Stuart

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  • Stefan

    We have built a relative complex system into the DS80C390, I expect more complex than most '51 systems, and much more complex than Intel's original intention for this type of microcontroller. We did this solely to save money, as this processor had nearly all features we needed and we had some experience of the DS87C520. It has proved to be more than quick enough for our purposes.

    I originally wrote this query a year or so ago and we have since got around the issue. Anyway here was the original problem.

    In a previous embedded system we had some code that created a number of menus based on a constant array, varying the amount of memory needed for each menu. This memory was malloc'ed at switch on. We intended to port this to this new system with as little changes as possible, as the system was relatively complex and worked. The malloc'ing was just done for convenience so that we did not need to keep extending the array when a menu item was added. This previous system also had a vast amount of memory (1MB).

    As we could not seam to use the keil malloc we rewrote the code so that it used a large array that was compiled in and then allocated to the menu items at startup, and checks to see if text file exceeds the array.

    I expect there are other way of achieving the same thing but it works and is quick enough so ….

    Anyway thanks for the help

    Stuart

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