Lpc2000

Love the LPC2129.
 
Can anyone explain why the following line of code is changing/resetting VPBDIV from 0x01 to 0x00??
 
IO0DIR = 0x006F0001;
 
Prior to this line IO0DIR is set to 0x006FFF01;
 
??  Thanks ??


Send instant messages to your online friends http://uk.messenger.yahoo.com 

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

I have a project with LPC21xx, directly supplied from non-isolated 
mains. Is there a possibility to optically isolate JTAG use ULINK? For 
development purposes I can use isolation transformer, but I would like 
to isolate hot part of the circuit from my PC to avoid any fatal 
accidents and stil have JTAG debuging.


Marko

Marko
  You might consider using an isolation transformer during testing.
That way you can also use other grounded test equipment - o'scope,
etc.  If the power needed is low and you do not have or can't find
an isolation transformer, two lower voltage transformers can be
wired back-to-back and used as a substitute.
	=>110v||24v=>24v||110v=>
Whichever way you choose, be careful.  Most folks are not use to working
on micros with deadly voltages present and needless to say, it can be
dangerous.

Regards
-Bill Knight
R O SoftWare &
http://www.theARMPatch.com


On Fri, 01 Apr 2005 13:54:15 +0200, Marko Pavlin wrote:


I have a project with LPC21xx, directly supplied from non-isolated 
mains. Is there a possibility to optically isolate JTAG use ULINK? For 
development purposes I can use isolation transformer, but I would like 
to isolate hot part of the circuit from my PC to avoid any fatal 
accidents and stil have JTAG debuging.


Marko



Yahoo! Groups Links

Sorry guys.  Guess I should have checked the Errata first.

Changing the standard UART0 code from (a) to (b) sorted it.

(a)

static unsigned int
peripheralClockFrequency(void)
{
  unsigned int divider;
  switch (VPBDIV & 3)
    {
      case 0:
        divider = 4;
        break;
      case 1:
        divider = 1;
        break;
      case 2:
        divider = 2;
        break;
    }
  return processorClockFrequency() / divider;
}

(b)
static unsigned int
peripheralClockFrequency(void)
{
  unsigned int divider;
  unsigned int vpbdivtemp;
  
  vpbdivtemp = VPBDIV;
  vpbdivtemp = VPBDIV;

  switch (vpbdivtemp & 3)
    {
      case 0:
        divider = 4;
        break;
      case 1:
        divider = 1;
        break;
      case 2:
        divider = 2;
        break;
    }
  return processorClockFrequency() / divider;
}

/******************************************************************/
There are 10 kinds of people: those who understand binary and those 
who don't.
/******************************************************************/


--- In lpc2000@yahoogroups.com, Adam Wilkinson <lpc2129@y...> wrote:
> Love the LPC2129.
>  
> Can anyone explain why the following line of code is 
changing/resetting VPBDIV from 0x01 to 0x00??
>  
> IO0DIR = 0x006F0001;
>  
> Prior to this line IO0DIR is set to 0x006FFF01;
>  
> ??  Thanks ??
> 
> 
> Send instant messages to your online friends 
http://uk.messenger.yahoo.com 
> 
> [Non-text portions of this message have been removed]

On 1 Apr 2005 at 13:54, Marko Pavlin wrote:

> 
> I have a project with LPC21xx, directly supplied from non-isolated
> mains. Is there a possibility to optically isolate JTAG use ULINK? For
> development purposes I can use isolation transformer, but I would like
> to isolate hot part of the circuit from my PC to avoid any fatal
> accidents and stil have JTAG debuging.
> 

If you are using a JTAG debugger with a serial interface, then it is not to difficult to
opto-isolate the serial connection. A ethernet interface is already isolated, and you
can put a small switch inbetween the debugger and PC, to add more isolation.

Regards
   Anton Erasmus
-- 
A J Erasmus

--- In lpc2000@yahoogroups.com, "Anton Erasmus" <antone@s...> wrote:
> On 1 Apr 2005 at 13:54, Marko Pavlin wrote:
> 
> > 
> > I have a project with LPC21xx, directly supplied from non-isolated
> > mains. Is there a possibility to optically isolate JTAG use
ULINK? For
> > development purposes I can use isolation transformer, but I would
like
> > to isolate hot part of the circuit from my PC to avoid any fatal
> > accidents and stil have JTAG debuging.
> > 
> 
> If you are using a JTAG debugger with a serial interface, then it is
not to difficult to
> opto-isolate the serial connection. A ethernet interface is already
isolated, and you
> can put a small switch inbetween the debugger and PC, to add more
isolation.
> 
> Regards
>    Anton Erasmus
> -- 
> A J Erasmus

Careful!  

An ethernet transformator has not been arranged for netspanning! A
colleague of me have kept at that a defective scoop, and it wanted to
can end worse.

Sorry for this a little bad automatic translated text, but my English
is yet more awful..

On 10 Apr 2005 at 19:52, lxlxlx_83 wrote:

> 
> 
> --- In lpc2000@yahoogroups.com, "Anton Erasmus" <antone@s...> wrote: >
> On 1 Apr 2005 at 13:54, Marko Pavlin wrote: > > > > > I have a project
> with LPC21xx, directly supplied from non-isolated > > mains. Is there
> a possibility to optically isolate JTAG use ULINK? For > > development
> purposes I can use isolation transformer, but I would like > > to
> isolate hot part of the circuit from my PC to avoid any fatal > >
> accidents and stil have JTAG debuging. > > > > If you are using a JTAG
> debugger with a serial interface, then it is not to difficult to >
> opto-isolate the serial connection. A ethernet interface is already
> isolated, and you > can put a small switch inbetween the debugger and
> PC, to add more isolation. > > Regards >    Anton Erasmus > -- > A J
> Erasmus
> 
> Careful!  
> 
> An ethernet transformator has not been arranged for netspanning! A
> colleague of me have kept at that a defective scoop, and it wanted to
> can end worse.

I am not exactely sure what you are warning against. Do you mean 
"line voltage" or "mains voltage" when you say netspanning ?

Are you saying that the ethernet transformer isolation voltage is not large
enough to handle 230V mains  ?

> Sorry for this a little bad automatic translated text, but my English
> is yet more awful..    

Maybe you can repeat your warning in your own language and ask someone to
translate into clearer english ?

Regards
   Anton Erasmus

 

-- 
A J Erasmus