| Author |
Message |
Andreas
Guest
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 Posted:
Mon Dec 06, 2004 3:57 pm Post subject:
How to estimate I/O and calculation power of a micro? |
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Hi!
I try to choose a micro fitting for my application.
I'm not sure how to estimate the power rating of the micro.
Basicly, I must handle 1 parallel printerport (with connected printer),
1 chipcard drive, 1 serial link to a GSM modem, a 4x4 keyboard matrix,
4x20 alphanumeric display (with its own display driving controller) and
4 serial 38,4 kBit/s links.
In a worst case all actions (keyboard hit, entering chipcard, display
output, I/O...) can take place at a time. Further, there is the
processing of the I/O data. Let's assume the task times are known.
Now, how much MIPS do I actually need? Is there a kind of approximation
formula or something?
Thanks in advance!
Best regards,
Andreas |
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EventHelix.com
Guest
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| Posted:
Tue Dec 07, 2004 8:09 am Post subject:
Re: How to estimate I/O and calculation power of a micro? |
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1. Estimate the approximate number of C code lines that will execute to
performing a transfer on the serial link.
2. Multiply this number by 4 to obtain the approximate number of
instructions.
3. Use the rate of the link to estimate the total instructions that
need to be executed per second. This
should give you a reasonable estimate.
Other operations on your processor do not seem to be computationaly
intensive.
Deepa
--
http://www.EventHelix.com/EventStudio
EventStudio 2.5 - Embedded System with Sequence Diagrams |
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Tauno Voipio
Guest
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| Posted:
Tue Dec 07, 2004 11:59 am Post subject:
Re: How to estimate I/O and calculation power of a micro? |
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Andreas wrote:
| Quote: | Hi!
I try to choose a micro fitting for my application.
I'm not sure how to estimate the power rating of the micro.
Basicly, I must handle 1 parallel printerport (with connected printer),
1 chipcard drive, 1 serial link to a GSM modem, a 4x4 keyboard matrix,
4x20 alphanumeric display (with its own display driving controller) and
4 serial 38,4 kBit/s links.
In a worst case all actions (keyboard hit, entering chipcard, display
output, I/O...) can take place at a time. Further, there is the
processing of the I/O data. Let's assume the task times are known.
Now, how much MIPS do I actually need? Is there a kind of approximation
formula or something?
Thanks in advance!
Best regards,
Andreas
|
IMHO, most of your processing load comes from the serial lines:
the 5 lines will generate up to 20000 interrupts / second
unidirectional and double that bidirectional. You have only
25 us per character including all overhead, if all the serial
connections are full duplex active together.
--
Tauno Voipio
tauno voipio (at) iki fi |
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