CKOPT....how to make it 1 again ?

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Guys,

 

How can I return CKOPT on atmega8 fusebit to 1 again ?

I put CLK as 1111 and 12MHz crystal has been connected but I can't not communicate...

 

from avrdude :

C:\WinAVR-20100110\bin>avrdude -p m8 -c usbasp -F -e -v

avrdude: Version 5.10, compiled on Jan 19 2010 at 10:45:23
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2009 Joerg Wunsch

         System wide configuration file is "C:\WinAVR-20100110\bin\avrdude.conf"

         Using Port                    : lpt1
         Using Programmer              : usbasp
         AVR Part                      : ATMEGA8
         Chip Erase delay              : 10000 us
         PAGEL                         : PD7
         BS2                           : PC2
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page
      Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  Max
W   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ---
-- ---------
           eeprom         4    20   128    0 no        512    4      0  9000  90
00 0xff 0xff
           flash         33    10    64    0 yes      8192   64    128  4500  45
00 0xff 0x00
           lfuse          0     0     0    0 no          1    0      0  2000  20
00 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  2000  20
00 0x00 0x00
           lock           0     0     0    0 no          1    0      0  2000  20
00 0x00 0x00
           calibration    0     0     0    0 no          4    0      0     0
 0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0
 0 0x00 0x00

         Programmer Type : usbasp
         Description     : USBasp, http://www.fischl.de/usbasp/

avrdude: auto set sck period (because given equals null)
avrdude: warning: cannot set sck period. please check for usbasp firmware update
.
avrdude: error: programm enable: target doesn't answer. 1
avrdude: initialization failed, rc=-1
avrdude: AVR device initialized and ready to accept instructions
avrdude: Device signature = 0x000000
avrdude: Yikes!  Invalid device signature.
avrdude: Expected signature for ATMEGA8 is 1E 93 07

avrdude done.  Thank you.

 

 

How can I fix it ?

thanks

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change are that you put it to external clk, (all programmed), and then you will need an external clk to your chip.

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do you mean I need to connect external clock to X1 ?

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will 1 MHz external clock be enough ? thanks

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yes , but read the data sheet, the spi speed need to be less than 1/4 of clk speed or something like that. (so just do it slow :) )

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I put 1MHz on X1, but still can not response...any ideas ? thanks

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Have you read this?:

 

https://www.avrfreaks.net/forum/t...

 

if that doesn't help I suspect you may have changed RSTDISBL in which case it will be time to throw away the mega and get a new one. (you cannot repair RSTDISBL with a USBAsp alone).

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no  I didn't change RSTDISBL....could  10MHz help  ?

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You chose to use -F
Anything might happen. Most likely, fuses will get set inappropriately.
David.

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I have encountered similar problem very confusing.

Recently I have had a few ATMEGA8A-AU ,Replace some old ATMEGA8L-8PU.

 

once CKOPT=0, The chip does not work.  crystal is 11.0592MHZ,49S.   20pF*2

 

Exactly the same circuit board, I used to deliberately programmed this fuse bit CKOPT,  In this new chip, this fuse bit cause it to stop oscillation.

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Eh? The difference between non-L and L parts is the speed range. The 8L is 2.7V..5.5V and 0..8MHz. The standard 8 is 4.5V..5.5V and 0..16MHz.

 

You cannot have been running L parts at 11.0592 and be within the specification.