Lpc2000

Simon Ansley wrote:

>Hello,
>
>I'm trying to get a new PCB up and running using an LPC2214, but 
>cannot get the chip to talk to the JTAG port. I'm fairly new to both 
>the processor, and ARM in general, so sorry if this is a really dumb 
>problem.
>
>I'm using a Segger J-Link (IAR rebadged) and Rowley compiler.
>
>I have connected to and run test code on the Olimex LPC2214 
>development board, so I know the J-Link is OK.
>
>I have checked and double checked the JTAG connection against the 
>Olimex schematic.
>
>I have the BSL (P0.14) connected to a pullup. Boot0 and Boot1 are 
>open circuit (high through internal pullups). RTCK is pulled low by 
>10K. 
>
>The processor oscillator is running.
>
>I've scoped the levels on the JTAG interface with the J-Link 
>unplugged, and they are identical on my and the Olimex board, with 
>the exception of TCK, which is at 0V on my board and approx 0.4V on 
>the Olimex board
>
>Whenever I try to connect from the Rowley IDE I get "Too few devices 
>on the JTAG bus. Selected Device :0, No. of Devices 0". I guess this 
>means the JLink simply can't see the processor for whatever reason.
>
>The board and chip are new, and have not have any code downloaded 
>into them. Do I need to download code using the Flash Loader utility 
>from the Phillips website, or should I be able to connect straight 
>away through the J-Link? 
>
>Does everything else sound OK, or could I have got a duff processor?
>
>
>  
>
I just brought up a new design using LPC2106 and LPC2138 processors.  
The first thing that I did was to see if they were "alive".  I connected 
to them via the UART0, gave them the '?' and echo'ed the "Synchronized" 
back to them. 

Once I had done that, I could assume that Clock operation was correct, 
Power Supplies were ok, Reset Circuit was okay, ...  IOW, the processors 
had the proper conditions to run with.

Next step was to attempt to connect via the Abatron BDI2000 JTAG, that 
worked as expected.  But, I was not about to subject the BDI2000 to an 
unknown board until  I had some level of confidence in the board.

I would scope the pins to see if the JTAG signals get to the processor 
pins, and see if the signals are clean, without glitches which would 
suggest a short.

I know that the BDI2000 will not attempt to connect to the board unless 
it first sees a VCC supply present on the JTAG connector.  Did you 
"edit" the JTAG connector pins and removed anything?


Hope this helps?

TomW



-- 
Tom Walsh - WN3L - Embedded Systems Consultant
http://openhardware.net, http://cyberiansoftware.com
"Windows? No thanks, I have work to do..."
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