technical_details.txt

AVR JTAG Software Debug Tools

Technical summary

The most interesting part is the data state in data phase 
and instruction phase. All other phases are necessary to
start and end the data phases and are standard procedures.
While the data is pushed out of the JTAG ICE box into the
target, the JTAG ICE box will receive data out of the target
simultanously. This is the most important item to remember.
In most cases you have an instruction and data phase :
both are introduced this way. Due to this fact, the strategy 
of this software package is to dump everything to the
secondary pc or secondary serial port.

Layout 

first column :
- this can be the first instruction ("I") or data state ("D").
- "R" is reset jtag state machine which is 5 times sending 
  TMS high while clocking the TMS pin.


The second column contains 2 characters :
- ("I") output from JTAG ICE box to target
- ("O") output from target to JTAG ICE box


Third and more columns

These columns contain only the data.