mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 557

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

14.2
Due to the nature of VREG_3V3 being a voltage regulator providing the chip internal power supply
voltages, most signals are power supply signals connected to pads.
14.2.1
Signal V
this pin. A chip external decoupling capacitor (>=100 nF, X7R ceramic) between V
is not available V
For entering shutdown mode, pin V
14.2.2
Signals V
regulator. Internal precision reference circuits are supplied from these signals. A chip external decoupling
capacitor (>=100 nF, X7R ceramic) between V
supply.
14.2.3
Signals V
These signals are connected to device pins to allow external decoupling capacitors (220 nF, X7R ceramic).
In shutdown mode an external supply driving V
Freescale Semiconductor
Table 14-1
DDR
External Signal Description
DDA
DD
shows all signals of VREG_3V3 associated with pins.
VDDR — Regulator Power Input Pins
VDDA, VSSA — Regulator Reference Supply Pins
VDD, VSS — Regulator Output1 (Core Logic) Pins
/V
is the power input of VREG_3V3. All currents sourced into the regulator loads flow through
/V
Check device level specification for connectivity of the signals.
SS
SSA,
V
SS
are the primary outputs of VREG_3V3 that provide the power supply for the core logic.
REGEN
) can smooth ripple on V
V
which are supposed to be relatively quiet, are used to supply the analog parts of the
V
Name
V
V
V
DDPLL
V
SSPLL
V
DDR
DDA
SSA
DD
SS
(optional)
Power input (positive supply)
Quiet input (positive supply)
Quiet input (ground)
Primary output (positive supply)
Primary output (ground)
Secondary output (positive supply)
Secondary output (ground)
Optional Regulator Enable
DDR
MC9S12XDP512 Data Sheet, Rev. 2.17
Table 14-1. Signal Properties
should also be tied to ground on devices without VREGEN pin.
DDR
Function
DDA
DD
.
NOTE
/V
and V
SS
can replace the voltage regulator.
SSA
can further improve the quality of this
Chapter 14 Voltage Regulator (S12VREG3V3V5)
Reset State
—
—
—
—
—
—
—
—
DDR
Pull Up
—
—
—
—
—
—
—
—
and V
SSR
(if V
SSR
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