3.2.2 Main Configuration and Control

This block depicts the main block for processor configuration and control:

  • XIN and XOUT are the Main Clock Oscillator input/output.
  • XIN32 and XOUT32 are the Slow Clock Oscillator input/output.
  • SHDN is an output signal used to enable and disable an external power supply circuit.
  • WKUP is an event detection input pin used to wake up the processor from Shutdown state.
  • JTAGSEL is an input that when pulled high enables the JTAG boundary scan.
  • TCK, TDI, TDO, TMS and RTCK are used for JTAG communication.
  • NRST is the processor main reset input.
  • HSD_A/B/C are the three USB ports embedded inside the MPU.
  • RTUNE is used for USB external tuning.
  • TST input is reserved for processor manufacturing tests.
  • ADVREFP and ADVREFN are the positive and negative reference points for the Analog to Digital Converter. A small low-pass filter is placed to reduce the input noise and improve accuracy.
  • DDR_VREF pin serves as a voltage reference input for the DDR I/Os.
  • DDRCAL is used to calibrate all DDR I/Os.
Figure 3-5. Processor Main Configuration and Control