[avrdude-dev] Re: How to talk to second device in JTAG chain?

[Grant Edwards]

On 2007-11-06, Grant Edwards <address@hidden> wrote:
> On 2007-11-05, Joerg Wunsch <address@hidden> wrote:

>> The attached patch adds a -j option that allows adjusting JTAG
>> daisy-chain parameters. [...]

> Brilliant!  I'll give it a try.

It works just fine.  FWIW, an MSP430 is "8 bits long".  With
the AVR preceded by the MSP430, configuring the avrdude for 1
device before and 8 bits before allowed avrdude to talk to the
AVR.

The MSP430 itself will work in a chain (as long as it's first
in the chain -- an obnoxious/ignorant decision by TI). However,
the bad news is that none of the TI SW tools can tolerate any
other devices in the chain at all (an even _more_
obnoxious/ignorant decision by TI).  If you ever run into the
TI guys who made those decisions (IIRC it was the group in down
in Freising), kick them in the shins for me. ;)

The fallback plan is to have a header with TRST, TCK and TDI
pins shared, with separate TDO and TMS pins for each device. :/

-- 
Grant Edwards                   grante             Yow! Edwin Meese made me
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