MC9S12E256 Datasheet, PDF (70/602 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 1 MC9S12E256 Device Overview (MC9S12E256DGV1)
Table 1-5. MC9S12E256 Power and Ground Connection Summary
Mnemonic
Nominal
Voltage
Description
VDD1, VDD2
VSS1, VSS2
VDDR
VSSR
VDDX
VSSX
VDDA
VSSA
VRH
VRL
VDDPLL
VSSPLL
2.5 V
0V
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
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.
External power and ground, supply to internal voltage regulator.
To disable voltage regulator attach V_DDR to V_SSR.
External power and ground, supply to pin drivers.
Operating voltage and ground for the analog-to-digital converter, the reference for the
internal voltage regulator and the digital-to-analog converters, allows the supply voltage to
the A/D to be bypassed independently.
Reference voltage high for the ATD converter, and DAC.
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.
MC9S12E256 Data Sheet, Rev. 1.08
70
Freescale Semiconductor