
Device Overview
MFR4200 Data Sheet, Rev. 0
44
Freescale Semiconductor
2.2.4.1
VDDX, VSSX — Power and Ground Pins for I/O Drivers
External power and ground for I/O drivers.
2.2.4.2
VDDR, VSSR — Power and Ground Pins for I/O Drivers and Internal
Voltage Regulator
External power and ground for I/O drivers and input to the internal voltage regulator.
NOTE
The VDDR pin enables the internal 3.3 V to 2.5 V voltage regulator. If this
pin is tied to ground, the internal voltage regulator is turned off.
2.2.4.3
VDD2_5, VSS2_5 — Core Power Pins
Power is supplied to the MFR4200 core through VDD2_5 and VSS2_5. This 2.5 V supply is derived from
the internal voltage regulator. No static load is allowed on these pins. If VDDR is tied to ground, the
internal voltage regulator is turned off.
NOTE
No load is allowed except for bypass capacitors.
2.2.4.4
VDDA, VSSA — Power Supply Pins for VREG
VDDA, VSSA are the power supply and ground input pins for the voltage regulator. They also provide the
reference voltages for the internal voltage regulator.
2.2.4.5
VDDOSC, VSSOSC — Power Supply Pins for OSC
VDDOSC, VSSOSC provide operating voltage and ground for the oscillator. This allows the supply
voltage to the oscillator to be bypassed independently. This 2.5V voltage is generated by the internal
voltage regulator.
NOTE
No load is allowed except for bypass capacitors.
2.3
System Clock Description
The internal Clock and Reset Generator block provides the internal clock signals for the FlexRay block
and all other modules.
Figure 2-5
shows the clock connections from the CRG to all modules.
Refer to
Chapter 5, “Clocks and Reset Generator
” for detailed information on clock generation.