2.11.3.1 TRST

Test-Logic Reset (TRST) is an active-low, asynchronous reset signal to the TAP controller. The TRST input can be used to reset the Test Access Port (TAP) Controller to the TRST state. The TAP Controller can be held at this state permanently by grounding the TRST pin. To hold the JTAG TAP controller in the TRST state, it is recommended to connect TRST to ground via a 1 kΩ resistor.

There is an optional internal pull-up resistor available for the TRST input that can be set by the user at programming. Care should be exercised when using this option in combination with an external tie-off to ground.

An on-chip Power-On-Reset (POWRST) circuit is included. POWRST has the same function as TRST, but it only occurs at power-up or during recovery from a VCCA and/or VCCDA voltage drop.