Subject:
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Re: Motor Drivers in 7000 - 7fff
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Mon, 4 May 1998 22:41:11 GMT
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Original-From:
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Charles Hacker EAS <C.HACKER@STE.GU.EDU.AUihatespam>
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Reply-To:
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c.hacker@eas.gu.edu.au+antispam+
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Viewed:
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1471 times
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Jaron,
>
> QUESTION - Why can the whole memory range from 7000 - 7fff be used to set
> the motor drivers or to fetch the digital input signals?
This was done (obviously) to save extra decoding circuitry needed on
the board.
That is, if the handy board needed to assign (say) 7000 as the motor
then sixteen address lines need to be decoded (binary 0111 000 000
000).
Yet with the address of 7000 - 7FFF, only the first four bits
(binary 0111 = 7) need to be decoded.
This is essentially wasteful in memory locations, yet with plently of
address space this is not really a problem.
Charles Hacker
School of Engineering
Griffith University - Gold Coast
PMB 50 Gold Coast Mail Centre
Southport Queensland 9726
Australia.
Email - C.Hacker@eas.gu.edu.au
Ph. (07) 55948 670
Fax.(07) 55948 065
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Message is in Reply To:
 | | Working with a different compiler 2
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| Howdy All, I am in a happy mood today. I finally got to the 'hello world' stage. All I had to do was count the number of interrupts, * 2 (16 bit addresses), subtract this from BFFF which is the reset vector and thus supply BFD6 to my linker to start (...) (27 years ago, 4-May-98, to lugnet.robotics.handyboard)
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