I designed my own custom board with the TMS470MF04207 microcontroller ，
i only provide single 3.3v supply as following picture shows, Because the datasheet says :"The core voltage is supplied and regulated by the device's internal voltage regulator. There is not need for an externally supplied core voltage." But when i power-up,VOLTAGE CORE (1.55 V) is no-voltage, and Jtag doesn't work,.
i have three boards, only one sometimes work. Now I measure VOLTAGE CORE pins, it is 1.55v. SO i think VOLTAGE CORE (1.55 V) is no-voltage so that my board doesn't work. is it right ?
Question : Now what can i do to make the core voltage output 1.55V? PS: I have already make the ENZ to 0V.