Lpc2000

I've had this happen.  What I had to do was reset the chip with P0.14 low to force it into ISP mode.  I then manually did the ISP commands via RX0/TX0 to erase the chip.  Once erased the JTAG will take control ok.

	-----Original Message-----
	From: lpc2000@yahoogroups.com [mailto:lpc2000@yahoogroups.com] On Behalf Of Tom Walsh
	Sent: Monday, October 24, 2005 1:09 PM
	To: lpc2000@yahoogroups.com
	Subject: Re: [lpc2000] destroyed LPC2138 via software
	
	
	Tom Walsh wrote:
	
	>This is not good.  I ran some code on the LPC2138 board of mine to track 
	>down a Data Abort that was being thrown.  Merely commenting out sections 
	>of code.  Now, after running that code on two boards, dumping memory via 
	>BDI2000 + JTAG I get a "Data Abort" when it attempts to dump anything 
	>above 0x0000:0040!
	>
	>Anyone else run into this?  That is it possible to destroy an LPC2000 
	>chip via software?
	>
	>  
	>
	Nothing like answering my own question.
	
	The problem appears to be the time interval between when the JTAG unit 
	asserts a hardware RESET and until it is able to seize control of the 
	CPU via the tap interface (JTAG).  During that interval, the processor 
	runs like hell and hits the abort'ing code.  Finally the JTAG is 
	operational, but now the CPU is abort'ed.
	
	For some really strange reason, the JTAG has no control over an aborted 
	processor?!
	
	The chip is not destroyed as I feared, it is merely totally fsck'ed and 
	won't work with the tap controller.
	
	
	TomW
	
	-- 
	Tom Walsh - WN3L - Embedded Systems Consultant
	http://openhardware.net, http://cyberiansoftware.com
	"Windows? No thanks, I have work to do..."
	----------------------------------------------------
	
	
	
	
	
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