Lpc2000

Hi,

I fabricated a board with LPC2106 on it (among other things) with this
"fancy" power supply from TI - TPS70851. Small package, single chip 3.3 and
1.8V regulator.

In addition, the board was designed so that secondary JTAG is used in order
to have most of the pins available in Debug mode. 

In order to get the chip into JTAG it has to be bootstrapped with the code
that will place those JTAG2 pins into their appropriate mode. That procedure
was flawless - the board was up and running. 

After completing all the necessary procedures the JTAG refused to identify
the board and connect to it. I tried every possible combination of power up
and reset (cutting power in all possible ways and forms). What ended up
working is SHORTING the 3.3V supply. After shoring out the 3.3V supply the
chip was detected and I was able to program it, debug it. basically do all
the good things.

My question is, (I couldn't find it in the docs), whether anyone came across
this problem? I'm guessing that I have a problem with power up sequence.
Perhaps one should ensure that the CPU core (1.8V line) is on before
powering up the IOs (3.3 V)?? Anyone with an opinion?

Thanks in advance,

Cheers,

m.



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