Lpc2000

My LPC2132 fails to start running about 1/100 power-ups. 99 out of 
100, everything is OK.  
The Symptoms when if fails:
 a) Crystal does not oscillate. No voltage on either crystal osc 
pin. 
 b) No firmware appears to ever run or initialize anythign in my 
hardware.
 c)I/O pins are still inputs. 
 d)P0.14 is pulled low by CPU (I have a 10K P/U on it).  This 
symptom baffles me.  

When it is broke, I tried asserting reset low manually.  It does not 
clear the condition.   P0.14 stays stuck low, even with a manual 
reset. (power stays on through the reset. )

 I have checked the usual issues (P0.31 is pulled-up w/10K, P0.14 is 
pulled up w/10K, P1.20 is pulled up w/4.7K, PU on all JTAG lines 
except 10K PD on TCK)  

I've got a number of boaords doing this.  Power on, reset was 
assered properly, but XTAL does not start.  CPU appears to be 
dead.    Any ideas would be much appreciated.  

Some I/O pins go to circuits that have zigh-z (>1Mohm) paths to 5V, 
and the 5V does come up before the 3.3.  Could this be it?  

Thanks in advance for any comments.
John

----- Original Message ----- 

From: "johnsonnenberg99" <johnsonnenberg99@...>
To: <lpc2000@yahoogroups.com>
Sent: Friday, February 03, 2006 7:03 PM
Subject: [lpc2000] Unrelialble 2132 start-up problem.


> My LPC2132 fails to start running about 1/100 power-ups. 99 out of
> 100, everything is OK.
> The Symptoms when if fails:
> a) Crystal does not oscillate. No voltage on either crystal osc
> pin.
> b) No firmware appears to ever run or initialize anythign in my
> hardware.
> c)I/O pins are still inputs.
> d)P0.14 is pulled low by CPU (I have a 10K P/U on it).  This
> symptom baffles me.
>
> When it is broke, I tried asserting reset low manually.  It does not
> clear the condition.   P0.14 stays stuck low, even with a manual
> reset. (power stays on through the reset. )
>
> I have checked the usual issues (P0.31 is pulled-up w/10K, P0.14 is
> pulled up w/10K, P1.20 is pulled up w/4.7K, PU on all JTAG lines
> except 10K PD on TCK)
>
> I've got a number of boaords doing this.  Power on, reset was
> assered properly, but XTAL does not start.  CPU appears to be
> dead.    Any ideas would be much appreciated.
>
> Some I/O pins go to circuits that have zigh-z (>1Mohm) paths to 5V,
> and the 5V does come up before the 3.3.  Could this be it?
>
> Thanks in advance for any comments.

The 5 V on the I/Os before power is applied could be the cause. I don't know 
about the '2132, but it is mentioned in the '2106 data - there shouldn't be 
any voltage on the pins before the Vdd3 supply is present, if I am reading 
it correctly.

Leon

Hi John,
   
  Had u pulled the P0.14 PIN TO LOW. 
  Since u connected a 10k pull up, just check the pin with a multimeter.
   
  Provide the Power Supply as per in the User Manual.
  or try by inserting external switch on reset.
  I had the same problem in LPC2138. I connected only a 10k pullup to the P0.14 Pin and a i grounded via a jumper. Then in the reset pin i used the same 10k pull up with an external reset switch it worked properly.
   
  U can see the schematic files in the LPC groups.
   
  cheers,
  Rajender
   
   
  

johnsonnenberg99 <johnsonnenberg99@...> wrote:
  My LPC2132 fails to start running about 1/100 power-ups. 99 out of 
100, everything is OK.  
The Symptoms when if fails:
a) Crystal does not oscillate. No voltage on either crystal osc 
pin. 
b) No firmware appears to ever run or initialize anythign in my 
hardware.
c)I/O pins are still inputs. 
d)P0.14 is pulled low by CPU (I have a 10K P/U on it).  This 
symptom baffles me.  

When it is broke, I tried asserting reset low manually.  It does not 
clear the condition.   P0.14 stays stuck low, even with a manual 
reset. (power stays on through the reset. )

I have checked the usual issues (P0.31 is pulled-up w/10K, P0.14 is 
pulled up w/10K, P1.20 is pulled up w/4.7K, PU on all JTAG lines 
except 10K PD on TCK)  

I've got a number of boaords doing this.  Power on, reset was 
assered properly, but XTAL does not start.  CPU appears to be 
dead.    Any ideas would be much appreciated.  

Some I/O pins go to circuits that have zigh-z (>1Mohm) paths to 5V, 
and the 5V does come up before the 3.3.  Could this be it?  

Thanks in advance for any comments.
John











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[Non-text portions of this message have been removed]

I found the problem.  The DC supply had a false start. For the 500mS 
or so before it would ramp-up to 3.3V, it would wobble around .5-
1V.  This was due to leakage through a 232 driver as well as an 
idosyncracy of the DC supply.  During the wobble, Reset was hard 
low, so I'm suprised the voltage on Vcc mattered.  Putting a 1k pull-
down on the 3.3V to ensure when the 3.3V is OFF, the Vcc of the 
LPC2132 goes to all the way to ground, fixed the problem.  
Live and learn. 

--- In lpc2000@yahoogroups.com, Rock Raj <rockraj_2003@...> wrote:
>
> Hi John,
>    
>   Had u pulled the P0.14 PIN TO LOW. 
>   Since u connected a 10k pull up, just check the pin with a 
multimeter.
>    
>   Provide the Power Supply as per in the User Manual.
>   or try by inserting external switch on reset.
>   I had the same problem in LPC2138. I connected only a 10k pullup 
to the P0.14 Pin and a i grounded via a jumper. Then in the reset 
pin i used the same 10k pull up with an external reset switch it 
worked properly.
>    
>   U can see the schematic files in the LPC groups.
>    
>   cheers,
>   Rajender
>    
>    
>   
> 
> johnsonnenberg99 <johnsonnenberg99@...> wrote:
>   My LPC2132 fails to start running about 1/100 power-ups. 99 out 
of 
> 100, everything is OK.  
> The Symptoms when if fails:
> a) Crystal does not oscillate. No voltage on either crystal osc 
> pin. 
> b) No firmware appears to ever run or initialize anythign in my 
> hardware.
> c)I/O pins are still inputs. 
> d)P0.14 is pulled low by CPU (I have a 10K P/U on it).  This 
> symptom baffles me.  
> 
> When it is broke, I tried asserting reset low manually.  It does 
not 
> clear the condition.   P0.14 stays stuck low, even with a manual 
> reset. (power stays on through the reset. )
> 
> I have checked the usual issues (P0.31 is pulled-up w/10K, P0.14 
is 
> pulled up w/10K, P1.20 is pulled up w/4.7K, PU on all JTAG lines 
> except 10K PD on TCK)  
> 
> I've got a number of boaords doing this.  Power on, reset was 
> assered properly, but XTAL does not start.  CPU appears to be 
> dead.    Any ideas would be much appreciated.  
> 
> Some I/O pins go to circuits that have zigh-z (>1Mohm) paths to 
5V, 
> and the 5V does come up before the 3.3.  Could this be it?  
> 
> Thanks in advance for any comments.
> John
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
>   SPONSORED LINKS 
>         Microcontrollers   Microprocessor   Intel 
microprocessors     Pic microcontrollers 
>     
> ---------------------------------
>   YAHOO! GROUPS LINKS 
> 
>     
>     Visit your group "lpc2000" on the web.
>     
>     To unsubscribe from this group, send an email to:
>  lpc2000-unsubscribe@yahoogroups.com
>     
>     Your use of Yahoo! Groups is subject to the Yahoo! Terms of 
Service. 

> 
>     
> ---------------------------------
>   
> 
> 
> 
> 				
> ---------------------------------
>  Jiyo cricket on Yahoo! India cricket
> 
> [Non-text portions of this message have been removed]
>