MC9S12K Datasheet, PDF (84/126 Pages) Freescale Semiconductor, Inc – Microcontrollers

Device User Guide — 9S12KT256DGV1/D V01.09
The VDDR, VSSR pair supplies the internal voltage regulator.
VDD1, VSS1, VDD2 and VSS2 are the supply pins for the digital logic.
VDDPLL, VSSPLL supply the oscillator and the PLL.
VSS1 and VSS2 are internally connected by metal.
VDD1 and VDD2 are internally connected by metal.
VDDA, VDDX, VDDR as well as VSSA, VSSX, VSSR are connected by anti-parallel diodes for ESD
protection.
NOTE:
In the following context VDD5 is used for either VDDA, VDDR and VDDX; VSS5
is used for either VSSA, VSSR and VSSX unless otherwise noted. IDD5 denotes the
sum of the currents flowing into the VDDA, VDDX and VDDR pins. VDD is used
for VDD1, VDD2 and VDDPLL, VSS is used for VSS1, VSS2 and VSSPLL. IDD is
used for the sum of the currents flowing into VDD1 and VDD2.
A.1.3 Pins
There are four groups of functional pins.
A.1.3.1 3.3V/5V I/O pins
Those I/O pins have a nominal level of 3.3V or 5V depending on the application operating point. This
group of pins is comprised of all port I/O pins, the analog inputs, BKGD pin and the RESET inputs.The
internal structure of all those pins is identical, however some of the functionality may be disabled. E.g. for
the analog inputs the output drivers, pull-up and pull-down resistors are disabled permanently.
A.1.3.2 Analog Reference
This group of pins is comprised of the VRH and VRL pins.
A.1.3.3 Oscillator
The pins EXTAL, XTAL dedicated to the oscillator have a nominal 2.5V level. They are supplied by
VDDPLL.
A.1.3.4 PLL
The pin XFC dedicated to the oscillator have a nominal 2.5V level. It is supplied by VDDPLL.
A.1.3.5 TEST
This pin is used for production testing only.
A.1.4 Current Injection
Power supply must maintain regulation within operating V_DD5 or V_DD range during instantaneous and
operating maximum current conditions. If positive injection current (V_in > V_DD5) is greater than I_DD5, the
injection current may flow out of VDD5 and could result in external power supply going out of regulation.
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