Schematic considerations for MSP430?

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I know that I've seen a TI document about this before, but a 15 minute
google search left me with nothing.

I am double-checking a schematic that uses an MSP430F149, and I want
to ensure that I have all the pins correctly terminated for (1)
correct operations and (2) access to the JTAG port for in-circuit
programming and debugging.  Here's what I've got:

AVcc   -- 3.3V
DVcc   -- 3.3V
DVss   -- GND
AVss   -- GND
XIN    -- GND
VeRef+ -- GND
VeRef- -- GND
RST    -- Pulled up to 3.3V, with a connector at pin
TCK    -- Connector at pin
TMS    -- Connector at pin
TDI    -- Connector at pin
TDO    -- Connector at pin

Everything else is open (except for some inputs and outputs that I am
using).  I am using the internal oscillator as clock.

Any help (whether a reference to a document or a check of my pinout)
will be greatly appreciated.


Re: Schematic considerations for MSP430?

TI have a demo board based on the msp430f149, you can check all the
connections against that.

I'm not sure it's schematic is on the web, but i could dig it out for you if
your having problems finding it.


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Re: Schematic considerations for MSP430?
Thank you for the offer, but I do have that schematic.  The things
that I noticed about it is that it has a filter capacitor on the DVcc
and AVcc lines, and that it actually connects the XOUT pin to the JTAG

I have added a capacitor to mine (100nF ceramic), put have not put a
lead on XOUT, because I read elsewhere on USENET That this pin is no
longer necessary.


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Re: Schematic considerations for MSP430?
Quoted text here. Click to load it

Not sure about tying RST high. TI's demo schems always use an RC reset
in the range 10K-100K (though I think 30K is the "upper limit" according
to other documentation) + 100n, and this works in the lab. The MSP's
hardware brownout does leave a hole however, so I would recommend an
external reset chip as best practice.

You can leave VeRef+ floating. I'd be tempted to do the same with XIN,
it might be biassed.

Most of the demo files have a ASCII schematic in a big comment at the top.


Mike Page BEng(Hons) MIEE 
Quiet! Tony's battling the forces of conservatism, whoever we are.

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