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young
Joined: 24 Jun 2004
Posts: 285
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 Posted: Mon Nov 08, 2004 3:19 pm |
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Twom thing important to understand from your posting.
one is Never put those huge delays in there
another is There is no #int_rda with a software USART
thank you guys |
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Twitie
Joined: 08 Nov 2004
Posts: 11
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| Posted: Mon Nov 08, 2004 5:34 pm |
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5. Never put those huge delays in there. Better to set a flag and handle in main.
6. Better use "ERRORS" in the #use RS232 if using the hardware uart.
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Sorry guys for interrupt~ I have some doubt regarding your postings. Hope that anyone of you can answer my doubt.
Q1> Why we shouldn't use those huge delays in the program? 300ms is considered huge?
Q2> If so, what is the better way to implement delay? (coz I am using delay in my program too... just like young)
Q3> What is the usage of "ERRORS" in #use RS232?
Thank you very much! Looking forward for your replies~ |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Mon Nov 08, 2004 6:14 pm |
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| Quote: | Q1> Why we shouldn't use those huge delays in the program? 300ms is considered huge?
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Okay for a program but you shouldn't do them in an interrupt.
| Quote: | ERRORS
Used to cause the compiler to keep receive errors in the variable RS232_ERRORS and to reset errors when they occur.
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He is not doing any error checking. A buffer overrun will cause the receive to stop working unless the error is handled. The ERROR parameter will do this for him. |
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Twitie
Joined: 08 Nov 2004
Posts: 11
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| Posted: Mon Nov 08, 2004 7:16 pm |
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Thx Mark~ ^^
| Quote: | Okay for a program but you shouldn't do them in an interrupt.
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One more question. What should I do if I need to implement delay in intterupt?
Thx. |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Mon Nov 08, 2004 8:21 pm |
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Rewrite it so you don't 
Usually you can set a flag and then handle the interrupt in the main loop. Ints are supposed to be as short and fast as possible. |
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Twitie
Joined: 08 Nov 2004
Posts: 11
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| Posted: Mon Nov 08, 2004 8:27 pm |
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That's mean I use the interrupt subroutine only to set the flag and the all the work for interrupt will be done in main()...
Thx Mark, I think I get your point~~ |
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