Lpc2000

Em Seg 10 Abr 2006 18:26, ws kendall escreveu:
> I'm new to this group and to the 2000 architecture.  I have a design that
> was initially coded on the IAR 2106 dev board.  We've now moved that to our
> own hardware.

Me too. Unfortunatelly I never had such problems, the best I can is to say to 
you wath may NOT be the problem...

> The problem that I'm experiencing is that I cannot flash the controller on
> my hardware more than once.  Once flashed, the controller is unresponsive
> to attempts to connect to the loader.  The design is a mixed 3v/5v
> design.  I discovered that I was driving the controller's reset pin with a
> 5v signal (banging my forehead on the desk).  So, we hacked the board and
> are now driving reset with a 3v signal.  I had thought that that would
> solve my problem - 5v eventually burns out the reset pin circuit so of
> course I can't communicate with the loader because I can't reset the
> controller.  Application code runs fine.

If the application runs fine, you didnt burnt the reset pin.

> While the 5v on a 3v pin surely must have contributed, it doesn't seem to
> be the entire cause.  We fixed the 5v reset problem but still can only
> program virgin controllers.  Since, P0.14 is a port pin I didn't change the
> circuit that drives it.  Now I've gotten to wondering if that pin and the
> perhaps the Rx/Tx connections to serial 0 must also be at 3v levels during
> programming.  The data sheet appears somewhat vague about just which pins
> are 5v tolerant but it does say that there are 32 general purpose I/O pins
> that are and interestingly enough, P0 just happens to be 32 bits wide,
> therefore I can assume, can I not, that those are the pins that are 5v
> tolerant?

Yes, they are. I program my LPC2106 devices with a simple MAX232 (the ones I 
could find to buy on local electronic components sales) powered at 5V. The 
LPC2106 TX has enough voltage to drive the MAX232 and the RX works fines with 
5V signals. So far I programed about 10 pieces, all worked fine. 
So, maybe thats not the problem to you.

I take a little care with P014. I put a pull up resistor on it, 100k ohms, to 
+3,3V, and another resistor, 4,7k ohms, to my programming connector. That pin 
on the conector is connected (in my "programmer") to switch wich connects 
that pins to ground. So, when I select my switch to ISP, I have on P0.14 a 
resistor divider with 100k and 4k7 to give him a low signal. With the switch 
open, or my programmer disconnected, the pin becomes high with the 100k 
resistor. Works fine. Its nice because I use the UART0 for debug pouposes, so 
with the ISP switch opened I use the serial port for debug, with the switch 
closed, I use to program it.
I made it with the Philips ISP program, and in Linux (most of the time) with 
the lpc21isp program. The only issue I founded is that the lpc21isp do not 
configures correctly the serial board. I allways has to open minicom, close 
minicom (the serial port becomes reconfigured) and then I run lpc21isp. 
When (or if) I finish my actual project, I will work on lpc21isp to correct 
this...

> If any of you have had this or similar problems with flashing the 210x
> family, I surely appreciate whatever help you can send my way.
>
> There isn't any "security" bit somewhere that would prevent me from
> connecting to the loader is there?  That makes no sense to be but there
> have been stranger things ...

No, unfortunatelly not. LPC210X do not have any kind of protecting for the 
firmware, wich is making me to not sleep...

> Scott
>
> Systronix, Inc
> Salt lake City, Utah
>
Xultz
Curitiba - Brazil