Lpc2000

I've designed an LP2106 board that includes a few special features I need 
such as MIDI, an EPROM, etc.  I've had the alpha PCB manufactured and 
intalled the parts, and am now testing.  (If I can get this working, I may 
make the design available in the list archives as its MIDI capabilites could 
be useful to others)

I put a JPG of the schematic here 
http://members.shaw.ca/photonwind/Images/Processor%20Schematic.JPG.

I first populated the power supply parts and verified that the voltages were 
correct.  Then I populated all the parts related to the processor, reset, 
and the MAX3221 serial converter.

I'm now trying to get the bootloader to work.  I installed the jumper to tie 
P0.14 low, started up the Philips bootload utility, set 9,600 baud and set 
the crystal frequency to 14746 khz to match the board's crystal.

Then I pressed the "Upload to Flash" button and hit the reset button  when 
promped.  The board does not respond.  I can trace the RS232 signal from the 
PC through the MAX3221 to the correct pin on the LP2106.  I also verified 
that the Reset button is pulling the RST pin low, and the P0.14 pin is 
really pulled low.

I see no signal being returned by the board out of TXD0 to the MAX3221.

I've done all this in the past with a TiniArm board and the setup external 
to the board is the same, so I know generally what I'm doing.

Is this a reasonable way to test a new board?  Have I overlooked anything?

Thanks in advance.

- Chris

At 02:25 PM 9/15/04 -0700, you wrote:
<snip>
>I'm now trying to get the bootloader to work.  I installed the jumper to tie
>P0.14 low, started up the Philips bootload utility, set 9,600 baud and set
>the crystal frequency to 14746 khz to match the board's crystal.
>
>Then I pressed the "Upload to Flash" button and hit the reset button  when
>promped.  The board does not respond.  I can trace the RS232 signal from the
>PC through the MAX3221 to the correct pin on the LP2106.  I also verified
>that the Reset button is pulling the RST pin low, and the P0.14 pin is
>really pulled low.
>
>I see no signal being returned by the board out of TXD0 to the MAX3221.
>
>I've done all this in the past with a TiniArm board and the setup external
>to the board is the same, so I know generally what I'm doing.
>
>Is this a reasonable way to test a new board?  Have I overlooked anything?

Have you verified that the clock is running?

Next question would be are connected to an input pin on the MAX?

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,
be they legal, genetic, or physical.  If you don't believe me, try to
chew a radio signal. "

                         Kelvin Throop, III

Thanks Robert,

> Have you verified that the clock is running?

Yes I can see the clock on my oscilloscope scope and the frequency is 
correct to the accuracy I can measure.

>
> Next question would be are connected to an input pin on the MAX?
>

I can see the RS232 signal at the board input with the oscilloscope, and I 
can also see a logic level version of the signal coming out of the MAX, and 
arriving the RXD0 pin of the LP2106.  When I check the TXD0 pin I see no 
signal.

- Chris

At 02:36 PM 9/15/04 -0700, you wrote:
>Thanks Robert,
>
> > Have you verified that the clock is running?
>
>Yes I can see the clock on my oscilloscope scope and the frequency is
>correct to the accuracy I can measure.
>
> >
> > Next question would be are connected to an input pin on the MAX?
> >
>
>I can see the RS232 signal at the board input with the oscilloscope, and I
>can also see a logic level version of the signal coming out of the MAX, and
>arriving the RXD0 pin of the LP2106.  When I check the TXD0 pin I see no
>signal.

OK, I'd do two things.  Not necessarily in this order.

- lift the Max pin that is connected to the TXD0 pin and then check the TXD 
pin for output.  That will verify it's not just being pulled down by the MAX.

- Use a simple terminal program and go through the initial startup sequence 
by hand.  It's a lot easier to repeat that way and the timing is totally 
under your control.

Hmm, a thought springs to mind.  An earlier poster ran into a problem with 
ISP and it turned out to be insufficient decoupling (on his driver chip if 
I remember correctly).

Also check the pin that takes the micro into JTAG mode, I don't remember if 
that is a potential problem and I don't have the reference to hand but it's 
worth verifying.

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,
be they legal, genetic, or physical.  If you don't believe me, try to
chew a radio signal. "

                         Kelvin Throop, III

--- In lpc2000@yahoogroups.com, "Chris Graham" <chris_e_gr@y...> 
wrote:
> I've designed an LP2106 board that includes a few special features 
I need 
> such as MIDI, an EPROM, etc.  I've had the alpha PCB manufactured 
and 
> intalled the parts, and am now testing.  (If I can get this 
working, I may 
> make the design available in the list archives as its MIDI 
capabilites could 
> be useful to others)
> 
> I put a JPG of the schematic here 
> http://members.shaw.ca/photonwind/Images/Processor%20Schematic.JPG.
> 
> I first populated the power supply parts and verified that the 
voltages were 
> correct.  Then I populated all the parts related to the processor, 
reset, 
> and the MAX3221 serial converter.
> 
> I'm now trying to get the bootloader to work.  I installed the 
jumper to tie 
> P0.14 low, started up the Philips bootload utility, set 9,600 baud 
and set 
> the crystal frequency to 14746 khz to match the board's crystal.
> 
> Then I pressed the "Upload to Flash" button and hit the reset 
button  when 
> promped.  The board does not respond.  I can trace the RS232 
signal from the 
> PC through the MAX3221 to the correct pin on the LP2106.  I also 
verified 
> that the Reset button is pulling the RST pin low, and the P0.14 
pin is 
> really pulled low.
> 
> I see no signal being returned by the board out of TXD0 to the 
MAX3221.
> 
> I've done all this in the past with a TiniArm board and the setup 
external 
> to the board is the same, so I know generally what I'm doing.
> 
> Is this a reasonable way to test a new board?  Have I overlooked 
anything?
> 
> Thanks in advance.
> 

Chris

Is pins 17 and 40 really not connected, as per your schematic?
With no I/O supply, I expect you won't be getting any I/O.
Hope this helps.
Greg

From: "Greg" <shem_an_na@...>
>
> Is pins 17 and 40 really not connected, as per your schematic?
> With no I/O supply, I expect you won't be getting any I/O.
> Hope this helps.
> Greg
>
Thanks Greg.  Yes, that was my dumb mistake!  I did eventually found it when 
checking the voltages on all the pins of the CPU, installed a jumper to make 
the connection, and like magic the board started working.  :-)))

Actually I did have them connected at one point, but must have accidentally 
deleted the wire when I extracted the CPU circuit from a larger circuit that 
contained other things.

- Chris