MC9S12DP256B Datasheet, PDF (66/126 Pages) Freescale Semiconductor, Inc – device made up of standard HCS12 blocks and the HCS12 processor core

MC9S12DP256B Device User G^Fui^rd^ee^e—^scV0^a2.^l1^e5 ^{Semiconductor, Inc.}
2.4.1 VDDX,VSSX — Power & Ground Pins for I/O Drivers
External power and ground for I/O drivers. Because fast signal transitions place high, short-duration
current demands on the power supply, use bypass capacitors with high-frequency characteristics and place
them as close to the MCU as possible. Bypass requirements depend on how heavily the MCU pins are
loaded.
2.4.2 VDDR, VSSR — Power & Ground Pins for I/O Drivers & for Internal
Voltage Regulator
External power and ground for I/O drivers and input to the internal voltage regulator. Because fast signal
transitions place high, short-duration current demands on the power supply, use bypass capacitors with
high-frequency characteristics and place them as close to the MCU as possible. Bypass requirements
depend on how heavily the MCU pins are loaded.
2.4.3 VDD1, VDD2, VSS1, VSS2 — Core Power Pins
Power is supplied to the MCU through VDD and VSS. Because fast signal transitions place high,
short-duration current demands on the power supply, use bypass capacitors with high-frequency
characteristics and place them as close to the MCU as possible. This 2.5V supply is derived from the
internal voltage regulator. There is no static load on those pins allowed. The internal voltage regulator is
turned off, if VREGEN is tied to ground.
NOTE: No load allowed except for bypass capacitors.
2.4.4 VDDA, VSSA — Power Supply Pins for ATD and VREG
VDDA, VSSA are the power supply and ground input pins for the voltage regulator and the analog to
digital converter. It also provides the reference for the internal voltage regulator. This allows the supply
voltage to the ATD and the reference voltage to be bypassed independently.
2.4.5 VRH, VRL — ATD Reference Voltage Input Pins
VRH and VRL are the reference voltage input pins for the analog to digital converter.
2.4.6 VDDPLL, VSSPLL — Power Supply Pins for PLL
Provides operating voltage and ground for the Oscillator and the Phased-Locked Loop. This allows the
supply voltage to the Oscillator and PLL to be bypassed independently.This 2.5V voltage is generated by
the internal voltage regulator.
NOTE: No load allowed except for bypass capacitors.
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