Motorola MC9S12DJ128B, MC9S12DT128B manual VDDX,VSSX Power & Ground Pins for I/O Drivers, Vssa

MC9S12DT128B Device User Guide — V01.07

Mnemonic	Pin Number	Nominal	Description
	112-pin QFP	Voltage
VDDR	41	5.0V	External power and ground, supply to pin drivers and internal
VSSR	40	0V	voltage regulator.
VDDX	107	5.0V	External power and ground, supply to pin drivers.
VSSX	106	0V
VDDA	83	5.0V	Operating voltage and ground for the analog-to-digital
			converters and the reference for the internal voltage regulator,
VSSA	86	0V	allows the supply voltage to the A/D to be bypassed
			independently.
VRL	85	0V	Reference voltages for the analog-to-digital converter.
VRH	84	5.0V
VDDPLL	43	2.5V	Provides operating voltage and ground for the Phased-Locked
			Loop. This allows the supply voltage to the PLL to be
VSSPLL	45	0V	bypassed independently. Internal power and ground
			generated by internal regulator.
VREGEN	97	5V	Internal Voltage Regulator enable/disable

NOTE: All VSS pins must be connected together in the application.

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.

2.4.2VDDR, 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.

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