Lpc2000

What about for the LPC213x and LPC214x series?  I think they only 
have 1 JTAG port, right?

--- In lpc2000@yahoogroups.com, Tom Walsh <tom@o...> wrote:
>
> varuzhandanielyan wrote:
> 
> >Maybe very silly question, but...
> >Can I use P1.24-P1.31 pins in my design as
> >IO, if I plan to debug the soft using JTAG,
> >particularly ULINK.
> >Technical data references, experience, opinions?
> >
> >  
> >
> I do.  The LPC2106 has a secondary JTAG port, you just need to 
turn it 
> on..   You must download the first Flash image without JTAG, but 
after 
> that it works fine: flash new program, debug, etc.
> 
> This is the code sequence in the first few bytes of my crt0.S:
> 
> ================ begin ====================
> _start:
> start:
> _mainCRTStartup:
> 
> // Initialize Interrupt System
> // - Set stack location for each mode
> // - Leave in System Mode with Interrupts Disabled
> // -----------------------------------------------
> ;
>       ldr   r0, JTAG2
>       ldr   r1, PINSELREG
>       str   r0, [r1]       // activate secondary JTAG port.
> ;
>       mov   r3, #65536
> startdelay:
>       subs  r3, r3, #1
>       bne   startdelay     // give debugger time to catch us.
> ;
> 
> =============== snip ======================
> 
> With JTAG2 & PINSELREG as:
> 
> ================= begin ===================
> JTAG2:
>    .word 0x55400000
> PINSELREG:
>    .word 0xe002c004
> ================== snip ===================
> 
> 
> The short delay loop lets the JTAG unit "catch up" and stop the 
> processor early in the boot process.  Otherwise, I've run into 
problems 
> where the processor will run into a brick wall (bad code) before 
the 
> JTAG can catch it out of reset.
> 
> 
> TomW
> 
> 
> -- 
> Tom Walsh - WN3L - Embedded Systems Consultant
> http://openhardware.net, http://cyberiansoftware.com
> "Windows? No thanks, I have work to do..."
> ----------------------------------------------------
>