'[uClinux-dev] continuously interrupt in 50ms'

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List:       uclinux-dev
Subject:    [uClinux-dev] continuously interrupt in 50ms
From:       "Hua zhang" <zhanghua () megabyte ! com ! cn>
Date:       2002-11-28 2:10:41
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Hi all:

   When implement the read() function of the device driver, I need to use interrupt \
continuously for about 50ms. I use a sensor to shoot the image, when it starts to \
shoot, it will generate a low to high DS signal when gets one byte data. I connect \
this signal to one external interrupt, and hope to use the external interrupt to get \
the image. In this 50ms peried, I first close uClinux's task schedule by disable one \
timer interrupt, and then hope the cpu doesn't deal with any other task except to \
response to the interrupts(about 352*288 times in 50ms). The external interrupt can \
only get part of the DS signal. I don't know how to make the cpu idle. I tried \
udelay() function, then the system seems die. 

  I have tried to use 
      save_flags();cli();
      .......
      sti();
  to get the image data. In the get image function, I need to get the state when the \
DS changes from low to high, and it wastes a lot of cpu time, and I can only get the \
whole image data when the sensor's frequence is low. Now I have to get the sensor \
image with higher frequence.

Any idea?

Thanks!

Hua.

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<DIV><FONT size=2>Hi all:</FONT></DIV>
<DIV><FONT size=2>&nbsp;</FONT></DIV>
<DIV><FONT size=2>&nbsp;&nbsp; When&nbsp;implement the read() function of the 
device driver, I need to use interrupt&nbsp;continuously for about 50ms. I use a 
sensor to shoot the image, when it starts to shoot, it will generate a low to 
high DS signal when gets one byte data. I connect this signal to one external 
interrupt, and hope to use the external interrupt to get the image. In this 50ms 
peried, I first close uClinux's task schedule by disable one timer interrupt, 
and then hope the cpu doesn't deal with any other task except to response to the 
interrupts(about 352*288 times in 50ms). The external 
interrupt&nbsp;can&nbsp;only&nbsp;get part of the DS signal.&nbsp;I don't know 
how to make the cpu idle. I tried udelay() function, then the system&nbsp;seems 
die. </FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT size=2>&nbsp; I have tried to use </FONT></DIV>
<DIV><FONT size=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
save_flags();cli();</FONT></DIV>
<DIV><FONT size=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;.......</FONT></DIV>
<DIV><FONT size=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; sti();</FONT></DIV>
<DIV><FONT size=2>&nbsp; to get the image data. In the get image function, I 
need to get the state when the DS changes from low to high, and it wastes a lot 
of cpu time,&nbsp;and I can only get the whole image data when the sensor's 
frequence is&nbsp;low.</FONT>&nbsp;<FONT size=2>Now I have to get the sensor 
image with higher frequence.</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT size=2>Any idea?</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT size=2>Thanks!</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT size=2>Hua.</FONT></DIV>
<DIV>&nbsp;</DIV></BODY></HTML>

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