Lpc2000

Richard wrote:

>I am having problems to the 2106 using the secondary JTAG, this is on
>a prototype board.  Keil gives me the message:
>
> "Couldn't stop the ARM device.  Check the JTAG cable"
>
>The particulars:
>
>Keil IDE
>DBGSEL is pulled low.
>RTCK is pulled low
>TRST, TDI, TDO, and TMS are pulled high
>TCK is pulled low
>14.7456 MHz Xtal
>
>I have used this setup in two ther designs without problems.  I
>configure PINSEL2 to 0x55400000 as I always have.
>
>I have slow the JTAG as slow as it will go.  I can see all the signals
>active on the logic analyser.  
>
>  
>
That sounds odd, there should be a DELAY setting someplace.  At least I 
have this with the Abatron BDI2000, I can assert a RESET for a specific 
interval, then a DELAY before it attempts to connect.

Sounds like that Keil is attempting to connect the JTAG immediately 
after releasing the RESET.  As you know, with the secondary JTAG of the 
LPC2106, you have to enable the secondary JTAG, then (I do this) put a 
short delay loop in before the actual startup code to allow the BDI2000 
to "catch" the processor before it runs the actual code.

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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