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kender
Joined: 09 Aug 2004
Posts: 768
Location: Silicon Valley
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| Could not start target. The target was not halted after... |
 Posted: Wed Jun 22, 2005 11:55 am |
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Colleagues,
I have made 2 identical PCBs with PIC18F6720 on them. One programs fine with the ICD-U. The other one doesn?t, and it gives the following message:
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Could not start target. The target was not halted after reset. Check target oscillator and MCLR.
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Checked the oscillator ? it?s oscillating. Checked the MCLR ? it's at +5V, and there is continuity. Re-flowed the RB6, RB7 etc. pins.
My fuses are the following:
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#include <18F6720.h>
#device ICD=TRUE
#device adc=8
#use delay(clock=11000000)
#fuses NOWDT,WDT128,HS, NOPROTECT, NOOSCSEN, BROWNOUT, BORV25, NOPUT, NOCPD, STVREN, DEBUG, NOLVP, NOWRT, NOCPB, NOEBTRB, NOEBTR, NOWRTD, NOWRTC, NOWRTB
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=9)
#use i2c(Master,Fast,sda=PIN_C4,scl=PIN_C3)
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What could go wrong?
Thanks,
Nick |
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Humberto
Joined: 08 Sep 2003
Posts: 1215
Location: Buenos Aires, La Reina del Plata
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| Posted: Wed Jun 22, 2005 12:22 pm |
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| Quote: |
Could not start target. The target was not halted after reset. Check target oscillator and MCLR.
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Typical hardware problem in the target board. Same problem when
inadvertidely I left a capacitor in the MCLR pin.
1) Re-recheck for good connections form ICD to target.
2) Re-recheck the MCLR circuit.
3) Measure if the 47K resistor is connected.
4) If you have two target boards, keep the board wich is running and
swap the microcontrollers.
5) Good luck.
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kender
Joined: 09 Aug 2004
Posts: 768
Location: Silicon Valley
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| Found it |
| Posted: Wed Jun 22, 2005 10:16 pm |
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The voltage at MCLR was +4.0V. I have a 0.1uF cap (SMT 0805) between MCLR and GND. When I removed it, the PIC allowed to run itself. When I have put the cap back, the PIC kept working. I guess there was a solder bridge under the cap.
Nick |
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Humberto
Joined: 08 Sep 2003
Posts: 1215
Location: Buenos Aires, La Reina del Plata
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| Posted: Thu Jun 23, 2005 4:54 am |
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| Quote: |
When I removed it, the PIC allowed to run itself. When I have put the cap back, the PIC kept working.
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All the info I have regarding this issue told the same:
to connect an ICD, the capacitor in the MCLR circuit must be removed.
After found the error you reconected it again. 
Do I miss something ? if so pls let me know.
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I guess there was a solder bridge under the cap.
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If you assume this, you wouldn´t read 4.0V in this point !!!
Keep well,
Humberto |
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kender
Joined: 09 Aug 2004
Posts: 768
Location: Silicon Valley
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| Posted: Thu Jun 23, 2005 11:20 am |
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Humberto,
I'll remove the cap anyways, because it will make the ICD work more reliably.
But the cause of my immediate problem might have been a short with resistance of about 190k. It could have been some flux residue for example. Together with a 47k resistor it formed a voltage divider, which brought the voltage down to +4.0V
Nick |
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