Author Topic: mm57109  (Read 3009 times)

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Offline Simon123

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mm57109
« on: August 22, 2013, 02:47:54 pm »
Hello

Does anywhone have datasheet for mm57109 number oriented processor-in National Semiconductor databook there is only small description and pinout.  :'(
 

Offline Paul Price

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Re: mm57109
« Reply #1 on: August 22, 2013, 03:45:06 pm »
You could email Nat Semi (TI now) and possibly get help on this discontinued calculator chip from one of their applications engineers.
 

Online PA0PBZ

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« Last Edit: August 22, 2013, 05:35:31 pm by PA0PBZ »
Keyboard error: Press F1 to continue.
 

Offline Simon123

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Re: mm57109
« Reply #3 on: August 22, 2013, 07:04:33 pm »
Thanks for quick response.
I will buy my for 5€(6.5dollars) at local electronics shop.
 

Offline Paul Price

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Re: mm57109
« Reply #4 on: August 22, 2013, 11:38:10 pm »
Interesting, but what can you use it for. It's max operating frequency is 800KHz and you must control it with an external MCU.
So here's the question:  You would have to parse and translate the calculations you wish performed into bytes and into Reverse Polish Notation and order the bytes after maybe converting the values you have from floating point variables. You then have to transfer (maybe 8-bytes of data plus instructions) and transfer them byte by byte to the math coprocessor and also send it the instructions for the operation to be performed. When the processor is finished calculating, you would have to transfer the 8 or so byte result to your MCU and  re-assemble the result into a float or integer or whatever to do the next calculation and repeat this process.

But with a modern PICC chip, for instance, say operating at 32MHz and programmed with C-language, at the same price or for free for a sample chip, but you could perform all these calculations in much less time than this co-processor and no have to work with RPN communication.

Although you would use up quite a bit of program memory on the PICC, it takes certainly many k of code to do some MCU computing at a high math level, and also takes some computing time to accomplish calculations, but you get the result you want in 24-bit or 32 bit accuracy.

 But your PCB real estate would be much less used up in supporting this chip which is not really TTL compatible with its signaling and control lines and clock, etc.

So what's the point of going to all this trouble to maybe get less using more time and money? If you wanted a sci-calculator you could buy one for a few bucks these days at your local discount store.

Everyone should have a hobby.

« Last Edit: August 22, 2013, 11:49:25 pm by Paul Price »
 

Offline Simon123

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Re: mm57109
« Reply #5 on: August 23, 2013, 10:18:00 am »
I want this for my Z80 project-its still simpler to use calculator chip then making calculations in software.
 

Offline Simon123

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Re: mm57109
« Reply #6 on: September 05, 2013, 04:25:18 pm »
Interestingly datasheet apeared on the datasheet archive :)
http://www.datasheetarchive.com/MM57109N-datasheet.html
 


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