103C8 and 103RC ,What are the differences configuration between these two processors? I am configuring with register level. i search and i think all features are same. someone use it for same project?

[HTuna.1]

if I add 4.7K pullup resistor to the SDA and SCL pins, the SDA and SCL pins stay LOW all the time.

[MM..1]

What pins, R or C ??? Zero info in question.