Hi E2E,
The datasheet indicates that there are internal pull-up/ pull-down resistors on the SIM IO pins as listed below.
1. Do I need to add extra pull-up resistors for SIMIO, SIM1IO, SIM2IO?
2. If the extra pull up resistors are needed, do they be pulled up to VDDIO?
3. What is the value of pull-up resistor you suggest?
Please see attached schematic, and kindly give your suggestion, thanks!
https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/151/8AC77NGGD_5F00_1A1G_5F00_191002_5F00_TI.7z