MC9S12KG128_10 Datasheet, PDF (27/606 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 1 MC9S12KG128 Device Overview (MC9S12KG128V1)
Mnemonic
VDD1 VDD2
VSS1
VSS2
VDDR
VSSR
VDDX
VSSX
VDDA
VSSA
VRH
VRL
VDDPLL
VSSPLL
Nominal
Voltage
2.5 V
0V
Table 1-3. Power and Ground
Description
Internal power and ground generated by internal regulator. These also allow an external
source to supply the core VDD/VSS voltages and bypass the internal voltage regulator.
3.3/5.0 V
0V
3.3/5.0 V
0V
3.3/5.0 V
0V
3.3/5.0 V
0V
2.5 V
0V
External power and ground, supply to pin drivers and internal voltage regulator.
External power and ground, supply to pin drivers.
Operating voltage and ground for the analog-to-digital converter and the reference for the
internal voltage regulator, allows the supply voltage to the A/D to be bypassed
independently.
Reference voltage high for the ATD converter.
Reference voltage low for the ATD converter.
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.
NOTE
All VSS pins must be connected together in the application. 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
MCU pin load.
1.2.2 Detailed Signal Descriptions
1.2.2.1 EXTAL, XTAL — Oscillator Pins
EXTAL and XTAL are the crystal driver and external clock pins. On reset all the device clocks are derived
from the EXTAL input frequency. XTAL is the crystal output.
1.2.2.2 RESET — External Reset Pin
An active low bidirectional control signal, it acts as an input to initialize the MCU to a known start-up state,
and an output when an internal MCU function causes a reset.
1.2.2.3 TEST — Test Pin
This input only pin is reserved for test.
NOTE
The TEST pin must be tied to VSS in all applications.
MC9S12KG128 Data Sheet, Rev. 1.16
Freescale Semiconductor
27