MC9S12XD256MAL Datasheet, PDF (66/1348 Pages) Freescale Semiconductor, Inc – Freescale’s Scalable Controller Area Network

Chapter 1 Device Overview MC9S12XD-Family
1.2.4.2
V_DDR1, V_DDR2, V_SSR1, V_SSR2 — Power and Ground Pins for I/O Drivers
and 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.
1.2.4.3 V_DD1, V_DD2, V_SS1, V_SS2 — Core Power Pins
Power is supplied to the MCU through V_DD and V_SS. 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 2.5-V 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 V_REGEN is tied to ground.
NOTE
No load allowed except for bypass capacitors.
1.2.4.4 V_DDA, V_SSA — Power Supply Pins for ATD and V_REG
V_DDA, V_SSA are the power supply and ground input pins for the voltage regulator and the analog-to-digital
converters.
1.2.4.5 V_RH, V_RL — ATD Reference Voltage Input Pins
V_RH and V_RL are the reference voltage input pins for the analog-to-digital converter.
1.2.4.6 V_DDPLL, V_SSPLL — 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 2.5-V voltage is generated by
the internal voltage regulator.
NOTE
No load allowed except for bypass capacitors.
MC9S12XDP512 Data Sheet, Rev. 2.21
66
Freescale Semiconductor