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Reset of circuit

Reset of circuit

2004-12-16 by albin_martinsson

Hi

Anyone know how to reset an LPC2129 from software? Just calling 
address 0x00000000 is not good, course the registers also needs to 
be reseted.

/Fredrik, V-Teknik, Sweden

Re: [lpc2000] Reset of circuit

2004-12-16 by Kerem Or

You may use an external reset circuit with open drain output and connect one 
of the LPCs I/O pins which defaults to input with weak pullup to the reset 
pin of LPC. When you define this I/O pin as output and drive to low will 
reset the LPC. At the same time the I/O pin will become an input pin again 
releasing the reset line. So the LPC will start normally.

Kerem

----- Original Message -----
Show quoted textHide quoted text
From: "albin_martinsson" <fredrik_m@...>
To: <lpc2000@yahoogroups.com>
Sent: Thursday, December 16, 2004 10:36 AM
Subject: [lpc2000] Reset of circuit


>
>
> Hi
>
> Anyone know how to reset an LPC2129 from software? Just calling
> address 0x00000000 is not good, course the registers also needs to
> be reseted.
>
> /Fredrik, V-Teknik, Sweden
>
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>

Re: Reset of circuit

2004-12-16 by albin_martinsson

Isn't there any way of doing this by just software? I have no chance 
of connecting some of the IO-pins just for reset. I want to do it 
from software.

/Fredrik


--- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
> You may use an external reset circuit with open drain output and 
connect one 
> of the LPCs I/O pins which defaults to input with weak pullup to 
the reset 
> pin of LPC. When you define this I/O pin as output and drive to 
low will 
> reset the LPC. At the same time the I/O pin will become an input 
pin again 
> releasing the reset line. So the LPC will start normally.
> 
> Kerem
> 
> ----- Original Message ----- 
> From: "albin_martinsson" <fredrik_m@t...>
> To: <lpc2000@yahoogroups.com>
> Sent: Thursday, December 16, 2004 10:36 AM
> Subject: [lpc2000] Reset of circuit
> 
> 
> >
> >
> > Hi
> >
> > Anyone know how to reset an LPC2129 from software? Just calling
> > address 0x00000000 is not good, course the registers also needs 
to
Show quoted textHide quoted text
> > be reseted.
> >
> > /Fredrik, V-Teknik, Sweden
> >
> >
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> >

Re: [lpc2000] Re: Reset of circuit

2004-12-16 by Kerem Or

Then let the watchdog expire. It will reset the chip but will not change the 
state of the reset pin. That means your external hardware (if you have any) 
connected to the LPC reset pin will not get reset.

kerem


----- Original Message -----
Show quoted textHide quoted text
From: "albin_martinsson" <fredrik_m@...>
To: <lpc2000@yahoogroups.com>
Sent: Thursday, December 16, 2004 5:00 PM
Subject: [lpc2000] Re: Reset of circuit


>
>
> Isn't there any way of doing this by just software? I have no chance
> of connecting some of the IO-pins just for reset. I want to do it
> from software.
>
> /Fredrik
>
>
> --- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
>> You may use an external reset circuit with open drain output and
> connect one
>> of the LPCs I/O pins which defaults to input with weak pullup to
> the reset
>> pin of LPC. When you define this I/O pin as output and drive to
> low will
>> reset the LPC. At the same time the I/O pin will become an input
> pin again
>> releasing the reset line. So the LPC will start normally.
>>
>> Kerem
>>
>> ----- Original Message ----- 
>> From: "albin_martinsson" <fredrik_m@t...>
>> To: <lpc2000@yahoogroups.com>
>> Sent: Thursday, December 16, 2004 10:36 AM
>> Subject: [lpc2000] Reset of circuit
>>
>>
>> >
>> >
>> > Hi
>> >
>> > Anyone know how to reset an LPC2129 from software? Just calling
>> > address 0x00000000 is not good, course the registers also needs
> to
>> > be reseted.
>> >
>> > /Fredrik, V-Teknik, Sweden
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > Yahoo! Groups Links
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>

Re: Reset of circuit

2004-12-16 by Karl Olsen

--- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
> Then let the watchdog expire. It will reset the chip but will not 
change the 
> state of the reset pin. That means your external hardware (if you 
have any) 
> connected to the LPC reset pin will not get reset.

Has anybody done this successfully?

On my LPC2114, I have tried doing a CPU reset by starting the 
watchdog and letting it expire.  But when it expires, the CPU just 
hangs, without restarting.  P0.14 isn't low, and it hasn't entered 
ISP mode.  I'm doing like this:

WDT->WDTC = PCLK_HZ/4; /* Timeout = 1 second */
WDT->WDMOD = 0x03;
WDT->WDFEED = 0xAA;
WDT->WDFEED = 0x55;

At this time I can see WDTV decrementing, and when it reaches zero, 
the system just hangs, and interrupt activity stops.

Karl Olsen

Re: Reset of circuit

2004-12-16 by Kerem Or

according to user manual:

if P0.14 is high while RESET#=0 then LPC attempts to execute user 
code (if a valid csum found at addr 0x14). It does not enter ISP 
mode. I suppose this is your case as described below

If P0.14 is low while RESET#=0 but also the watchdog overflow flag 
is set, then LPC ignores the state of P0.14 and attempts to start 
user code.

In both cases a valid checksum is required at location 0x14 for LPC 
to execute user code

more details in the manual (p217)

Kerem


--- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:
> 
> --- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
> > Then let the watchdog expire. It will reset the chip but will 
not 
> change the 
> > state of the reset pin. That means your external hardware (if 
you 
> have any) 
> > connected to the LPC reset pin will not get reset.
> 
> Has anybody done this successfully?
> 
> On my LPC2114, I have tried doing a CPU reset by starting the 
> watchdog and letting it expire.  But when it expires, the CPU just 
> hangs, without restarting.  P0.14 isn't low, and it hasn't entered 
> ISP mode.  I'm doing like this:
> 
> WDT->WDTC = PCLK_HZ/4; /* Timeout = 1 second */
> WDT->WDMOD = 0x03;
> WDT->WDFEED = 0xAA;
> WDT->WDFEED = 0x55;
> 
> At this time I can see WDTV decrementing, and when it reaches 
zero,
Show quoted textHide quoted text
> the system just hangs, and interrupt activity stops.
> 
> Karl Olsen

Re: Reset of circuit

2004-12-16 by ian48harry

As well as the other ways of forcing a hardware reset you can always 
add to the startup assembler code the instructions to set the 
registers, even if they are the same as at power-up.  I the "old 
days" it was deemed good practice to do this.

Ian

--- In lpc2000@yahoogroups.com, "albin_martinsson" <fredrik_m@t...> 
wrote:
Show quoted textHide quoted text
> 
> Hi
> 
> Anyone know how to reset an LPC2129 from software? Just calling 
> address 0x00000000 is not good, course the registers also needs to 
> be reseted.
> 
> /Fredrik, V-Teknik, Sweden

LPC2114 watchdog reset, was:Reset of circuit

2004-12-16 by Karl Olsen

It boots fine from flash at power on, so the checksum etc. is OK.  
And when it hangs after a watchdog "reset", pulling RESET# low can 
also reboot it correctly.
So has anybody actually seen the watchdog reset work?

Karl Olsen


--- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
> 
> according to user manual:
> 
> if P0.14 is high while RESET#=0 then LPC attempts to execute user 
> code (if a valid csum found at addr 0x14). It does not enter ISP 
> mode. I suppose this is your case as described below
> 
> If P0.14 is low while RESET#=0 but also the watchdog overflow flag 
> is set, then LPC ignores the state of P0.14 and attempts to start 
> user code.
> 
> In both cases a valid checksum is required at location 0x14 for LPC 
> to execute user code
> 
> more details in the manual (p217)
> 
> Kerem
> 
> 
> --- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:
> > 
> > --- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
> > > Then let the watchdog expire. It will reset the chip but will 
> not 
> > change the 
> > > state of the reset pin. That means your external hardware (if 
> you 
> > have any) 
> > > connected to the LPC reset pin will not get reset.
> > 
> > Has anybody done this successfully?
> > 
> > On my LPC2114, I have tried doing a CPU reset by starting the 
> > watchdog and letting it expire.  But when it expires, the CPU 
just 
> > hangs, without restarting.  P0.14 isn't low, and it hasn't 
entered
Show quoted textHide quoted text
> > ISP mode.  I'm doing like this:
> > 
> > WDT->WDTC = PCLK_HZ/4; /* Timeout = 1 second */
> > WDT->WDMOD = 0x03;
> > WDT->WDFEED = 0xAA;
> > WDT->WDFEED = 0x55;
> > 
> > At this time I can see WDTV decrementing, and when it reaches 
> zero, 
> > the system just hangs, and interrupt activity stops.
> > 
> > Karl Olsen

Re: [lpc2000] LPC2114 watchdog reset, was:Reset of circuit

2004-12-16 by Kerem Or

I'm going to deal with the same in a week or two. I'll get back to you if I 
figure out something.

Kerem

----- Original Message -----
Show quoted textHide quoted text
From: "Karl Olsen" <kro@...>
To: <lpc2000@yahoogroups.com>
Sent: Thursday, December 16, 2004 6:53 PM
Subject: [lpc2000] LPC2114 watchdog reset, was:Reset of circuit


>
>
>
> It boots fine from flash at power on, so the checksum etc. is OK.
> And when it hangs after a watchdog "reset", pulling RESET# low can
> also reboot it correctly.
> So has anybody actually seen the watchdog reset work?
>
> Karl Olsen
>
>
> --- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
>>
>> according to user manual:
>>
>> if P0.14 is high while RESET#=0 then LPC attempts to execute user
>> code (if a valid csum found at addr 0x14). It does not enter ISP
>> mode. I suppose this is your case as described below
>>
>> If P0.14 is low while RESET#=0 but also the watchdog overflow flag
>> is set, then LPC ignores the state of P0.14 and attempts to start
>> user code.
>>
>> In both cases a valid checksum is required at location 0x14 for LPC
>> to execute user code
>>
>> more details in the manual (p217)
>>
>> Kerem
>>
>>
>> --- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:
>> >
>> > --- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
>> > > Then let the watchdog expire. It will reset the chip but will
>> not
>> > change the
>> > > state of the reset pin. That means your external hardware (if
>> you
>> > have any)
>> > > connected to the LPC reset pin will not get reset.
>> >
>> > Has anybody done this successfully?
>> >
>> > On my LPC2114, I have tried doing a CPU reset by starting the
>> > watchdog and letting it expire.  But when it expires, the CPU
> just
>> > hangs, without restarting.  P0.14 isn't low, and it hasn't
> entered
>> > ISP mode.  I'm doing like this:
>> >
>> > WDT->WDTC = PCLK_HZ/4; /* Timeout = 1 second */
>> > WDT->WDMOD = 0x03;
>> > WDT->WDFEED = 0xAA;
>> > WDT->WDFEED = 0x55;
>> >
>> > At this time I can see WDTV decrementing, and when it reaches
>> zero,
>> > the system just hangs, and interrupt activity stops.
>> >
>> > Karl Olsen
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>

RE: [lpc2000] Re: Reset of circuit

2004-12-16 by Richard Rauscher

Yes, I've done it on both the 2114 and 2129.
The only difference is that I set WDTC = 0.
 
--rich
Show quoted textHide quoted text
	-----Original Message-----
	From: Karl Olsen [mailto:kro@...] 
	Sent: Thursday, December 16, 2004 7:36 AM
	To: lpc2000@yahoogroups.com
	Subject: [lpc2000] Re: Reset of circuit
	
	
	
	--- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
	> Then let the watchdog expire. It will reset the chip but will
not 
	change the 
	> state of the reset pin. That means your external hardware (if
you 
	have any) 
	> connected to the LPC reset pin will not get reset.
	
	Has anybody done this successfully?
	
	On my LPC2114, I have tried doing a CPU reset by starting the 
	watchdog and letting it expire.  But when it expires, the CPU
just 
	hangs, without restarting.  P0.14 isn't low, and it hasn't
entered 
	ISP mode.  I'm doing like this:
	
	WDT->WDTC = PCLK_HZ/4; /* Timeout = 1 second */
	WDT->WDMOD = 0x03;
	WDT->WDFEED = 0xAA;
	WDT->WDFEED = 0x55;
	
	At this time I can see WDTV decrementing, and when it reaches
zero, 
	the system just hangs, and interrupt activity stops.
	
	Karl Olsen
	
	
	
	
	
	
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[Non-text portions of this message have been removed]

Re: LPC2114 watchdog reset, was:Reset of circuit

2004-12-17 by tom_laffey

Karl,

Just today I was able to get my WD working.  I tested generating 
either an interrupt or a reset on the 2294 and both seem to do the 
right thing.  I had to add a delay before setting the WD, though, in 
order to get control with the debugger before the image in flash had 
already set the registers, since once the WD is enabled, your options 
are more limited.  This is the kind of "debuggability" issue you run 
into with any WD, though.  

Tom



--- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:
> 
>  
> It boots fine from flash at power on, so the checksum etc. is OK.  
> And when it hangs after a watchdog "reset", pulling RESET# low can 
> also reboot it correctly.
> So has anybody actually seen the watchdog reset work?
> 
> Karl Olsen
> 
> 
> --- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
> > 
> > according to user manual:
> > 
> > if P0.14 is high while RESET#=0 then LPC attempts to execute user 
> > code (if a valid csum found at addr 0x14). It does not enter ISP 
> > mode. I suppose this is your case as described below
> > 
> > If P0.14 is low while RESET#=0 but also the watchdog overflow 
flag 
> > is set, then LPC ignores the state of P0.14 and attempts to start 
> > user code.
> > 
> > In both cases a valid checksum is required at location 0x14 for 
LPC
Show quoted textHide quoted text
> > to execute user code
> > 
> > more details in the manual (p217)
> > 
> > Kerem
> > 
> > 
> > --- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:
> > > 
> > > --- In lpc2000@yahoogroups.com, "Kerem Or" <k.or@s...> wrote:
> > > > Then let the watchdog expire. It will reset the chip but will 
> > not 
> > > change the 
> > > > state of the reset pin. That means your external hardware (if 
> > you 
> > > have any) 
> > > > connected to the LPC reset pin will not get reset.
> > > 
> > > Has anybody done this successfully?
> > > 
> > > On my LPC2114, I have tried doing a CPU reset by starting the 
> > > watchdog and letting it expire.  But when it expires, the CPU 
> just 
> > > hangs, without restarting.  P0.14 isn't low, and it hasn't 
> entered 
> > > ISP mode.  I'm doing like this:
> > > 
> > > WDT->WDTC = PCLK_HZ/4; /* Timeout = 1 second */
> > > WDT->WDMOD = 0x03;
> > > WDT->WDFEED = 0xAA;
> > > WDT->WDFEED = 0x55;
> > > 
> > > At this time I can see WDTV decrementing, and when it reaches 
> > zero, 
> > > the system just hangs, and interrupt activity stops.
> > > 
> > > Karl Olsen

Re: LPC2114 watchdog reset, was:Reset of circuit

2004-12-17 by Karl Olsen

--- In lpc2000@yahoogroups.com, "tom_laffey" <tom_laffey@y...> wrote:
> 
> Karl,
> 
> Just today I was able to get my WD working.  I tested generating 
> either an interrupt or a reset on the 2294 and both seem to do the 
> right thing.  I had to add a delay before setting the WD, though, 
in 
> order to get control with the debugger before the image in flash 
had 
> already set the registers, since once the WD is enabled, your 
options 
> are more limited.  This is the kind of "debuggability" issue you 
run 
> into with any WD, though.  

Thanks.  Looks like I have to take a closer look at my code.

Karl Olsen

Re: LPC2114 watchdog reset, was:Reset of circuit

2004-12-17 by dave_albert

WD reset works fine for me on 2114 and 2124.

Be sure to disable interrupts when configuring the WD as any
instructions that interrupt the feed sequence will cause a reset.

--- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:
Show quoted textHide quoted text
> 
> --- In lpc2000@yahoogroups.com, "tom_laffey" <tom_laffey@y...> wrote:
> > 
> > Karl,
> > 
> > Just today I was able to get my WD working.  I tested generating 
> > either an interrupt or a reset on the 2294 and both seem to do the 
> > right thing.  I had to add a delay before setting the WD, though, 
> in 
> > order to get control with the debugger before the image in flash 
> had 
> > already set the registers, since once the WD is enabled, your 
> options 
> > are more limited.  This is the kind of "debuggability" issue you 
> run 
> > into with any WD, though.  
> 
> Thanks.  Looks like I have to take a closer look at my code.
> 
> Karl Olsen

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