i.MX8M Plus - WDOG_B# PU when using PCA9450C

[ramkrish]

Hi Team,

Do we need to mount 100k PU in WDOG_B# pin for using BSDL Mode?
As per Hardware Design Guide it says "If using a PMIC other than PCA9450, an external
pullup resistor (100 kΩ) may be required to support
Boundary-scan mode"

In EVK design it seems 100k PU was mounted in WDOG_B# pin they are using same PCA9450 PMIC.
Kindly confirm.

[yipingwang]

Although PCA9450C disables WDOG_B reset by default and the pull-up is not strictly required for normal operation, NXP recommends adding the 100 kΩ pull-up when Boundary-Scan support is required. The EVK also populates this resistor to ensure a defined WDOG_B level during BSDL testing and avoid potential reset issues when WDOG_B is floating in Boundary-Scan mode.