Hey there,

programming the new TAP is in progress and a other came up:

Function jtag_add_dr_scan() demands a "final State" where to move after 
scanning the DR. This final state has to be stable (self recursive like 
Pause-DR or Run/Test-Idle).

# Problem:
I wand to scan two times the DR. I want to take the way over Update DR. The 
shortcut over Exit2-DR to shift again does not work for this picky TAP. I could 
go over Run-Test/Idle, but this is wasting a tms.After a dr-scan I need to 
proceed to the Pause-DR or the Run-Test/Idle.
Cause: This causes the TAP-State machine to take the shortcut over Exit2-DR or 
the long way over Run-Test/Idle. But not the desired way over Update-DR 
--1--tms--> Select-DR-Scan.

# Possible solution:
there is a jtag_add_pathmove / jtag_add_statemove - function. The descriptions 
warns programmers to use this function only if really necessary. why is that? 
Does it mess up something?
Would this solve my Problem? Are there other possibilities?

# from: jtag.h:
 * Code that is relatively insensitive to the path taken through state
 * machine (as long as it is JTAG compliant) can use @a endstate for
 * jtag_add_xxx_scan(). Otherwise, the pause state must be specified as
 * end state and a subsequent jtag_add_pathmove() must be issued.
How ever, the following error will still cause trouble, as fare as I know.
*   - ERROR_JTAG_NOT_STABLE_STATE -- The final state was not stable.

# The desired move is:
TAP_IDLE 
TAP_DRSELECT       // first scan
TAP_DRCAPTURE
TAP_DRSHIFT x 35
TAP_DREXIT1
TAP_DRUPDATE
TAP_DRSELECT       // second scan
TAP_DRCAPTURE
TAP_DRSHIFT x 35
TAP_DREXIT1
TAP_DRUPDATE 

TAP_IDLE (or idle somewhere else)

Is it possible to archive this?
Xense


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