b9823103_ammer_for_ARM_and_Cortex_cores__Description
[Pin] 3 [Signal] nTRST [Type] Output [Description] 
JTAG Reset. Output from Flasher ARM to the Reset signal of the target JTAG port. Typically connected to nTRST of the target CPU. This pin is normally pulled HIGH on the target to avoid unintentional resets when there is no connection.
SEGGER | Flasher ARM | Flash Programmer for ARM and Cortex cores
Description