MC9S12D64 Datasheet, PDF (65/128 Pages) Freescale Semiconductor, Inc – Device User Guide V01.20

MC9S12DJ64 Device User Guide — V01.20
Pin Number
Mnemonic
112-pin QFP
VDDPLL
43
VSSPLL
45
VREGEN
97
Nominal
Voltage
2.5V
0V
5.0V
Description
Provides operating voltage and ground for the Phased-Locked
Loop. This allows the supply voltage to the PLL to be
bypassed independently. Internal power and ground
generated by internal regulator.
Internal Voltage Regulator enable/disable
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.
VDDX and VSSX are the supplies for Ports J, K, M, P, T and S.
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.
VDDR and VSSR are the supplies for Ports A, B, E and H.
2.4.3 VDD1, VDD2, VSS1, VSS2 — Internal Logic Power Supply 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 ATD0/ATD1 and VREG
VDDA, VSSA are the power supply and ground input pins for the voltage regulator and the two analog to
digital converters. It also provides the reference for the internal voltage regulator. This allows the supply
voltage to ATD0/ATD1 and the reference voltage to be bypassed independently.
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