Lpc2000

At 04:25 PM 4/3/05 +0000, arne_crouwels wrote:
>I'm building a board for the LPC2106, and all the software is working.
>But I don't exactly know what a JTAG is, is it hardware or software?
>And if it is software, is it the same as the Philips flashdownloader?


JTAG - an acronym for Joint Test Action Group.

In this context it refers to a standard interface developed for testing 
complex ICs in circuit on a PCB.  The interface has been adapted by many 
manufacturers for other purposes, in particular the ARM7 core has a debug 
module that uses the JTAG interface to communicate with a set of on-board 
circuitry that acts as a 'mini-ICE' allowing breakpoints to be set and 
memory to be read and written.

Several manufacturers build JTAG interfaces to communicate over this port 
with debugging SW.  Since using this you have full access to the memory it 
is possible to use this interface to program the flash as well.  The 
adapters and associated software range over a large range in terms of both 
price and sophistication.

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,   be 
they legal, genetic, or physical.  If you don't believe me, try to chew a 
radio signal. "  -- Kelvin Throop, III
http://www.aeolusdevelopment.com/