Ji junli

The monitor mode of MC68HC908JW32

Discussion created by Ji junli on Nov 29, 2006
Latest reply on Dec 4, 2006 by Michael Rhoades
I created a board of MC68HC908JW32.
but after I entered monitor mode of MC68HC908JW32 only one time,
I have not entered monitor mode of MC68HC908JW32 anymore.
I measured Vtst is about 8.2V.
there is reset button on my board.
 
when I connect Vtst to the pin IRQ,
after power on this board,
I use oscilloscope to measure the pin RESET and the pin OSC1, OSC2.
this pin RESET is always low and the crystal 9.804MHz can't work.
 
when I pull up the pin IRQ to 5V,
after power on this board,
I use oscilloscope to measure the pin RESET and the pin OSC1, OSC2 again.
this pin RESET is high and the crystal 9.804MHz can work normal;
if when I switch the pin IRQ to Vtst at this time,
I found the crystal 9.804MHz stop working at once,
but the pin RESET is still high.
 
I can't understand what happen.
please help me!
thanks a lot in advance!
 
best regards
jjl
 

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