Confused with the NJTRST signal role in JTAG debug
Hello,
I am currently working on a schematic featuring 3x STM32H753ZIT6 MCU , and I have a few questions regarding the JTAG implementation:
(1) From what I’ve gathered from various sources, the NJTRST signal is a JTAG ENABLE, meaning that in normal operation mode it must be tied to GND and driven to '1' only for JTAG debug. However, in some implementations on internet i've actually seen it connected to a pull-up resistors.
What is correct?
(2) I need to daisy-chain the JTAG between three components for debugging via an external channel. Does the NJTRST synchronize the three components for this purpose? In other words, should it be connected in parallel?
(3) And what about the NRST signal? Is it also used to synchronize the three components during JTAG debugging, or is it unrelated to this chain?
Thanx
Eli