120 MHz operation for SWO function in debugging

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by tvink on Thu Sep 17 12:40:59 MST 2015

My confusion
I am a little confused about what the SWO function is.  I know it is for trace functions and it is referred to as "optional" in the LPC1837 users manual.  But is it "necessary" for ARM debug mode without trace?
I am planning on running at 180 MHz and I see that SWO wont work if the CPU core is greater than 120 MHz.

I am planning on using an LPC Link-2 pod with LPCxpresso. 

I see mention in chapter 46 that the debugger comes up in JTAG mode and then switches to ARM Mode.  So what is the DBGEN pull up/down resistor for?

My questions
- To use LPC Link 2 with my 180MHz CPU should I pull up or down on the DBGEN pin for best debug (without trace) experience?  I.E. quick interaction... most break points.... etc.