S12 Clock, Reset and Power Management Unit (S12CPMU_UHV_V8)
MC9S12VRP Family Reference Manual Rev. 1.3
NXP Semiconductors
115
4.2
Signal Description
This section lists and describes the signals that connect off chip as well as internal supply nodes and special
signals.
4.2.1
RESET
Pin RESET is an active-low bidirectional pin. As an input it initializes the MCU asynchronously to a
known start-up state. As an open-drain output it indicates that an MCU-internal reset has been triggered.
4.2.2
EXTAL and XTAL
These pins provide the interface for a crystal to control the internal clock generator circuitry. EXTAL is
the input to the crystal oscillator amplifier. XTAL is the output of the crystal oscillator amplifier. If
XOSCLCP is enabled, the MCU internal OSCCLK_LCP is derived from the EXTAL input frequency. If
OSCE=0, the EXTAL pin is pulled down by an internal resistor of approximately 200 k
and the XTAL
pin is pulled down by an internal resistor of approximately 700 k
.
NOTE
Freescale recommends an evaluation of the application board and chosen
resonator or crystal by the resonator or crystal supplier.
The loop controlled circuit (XOSCLCP) is not suited for overtone
resonators and crystals.
4.2.3
VSUP — Regulator Power Input Pin
Pin VSUP is the power input of VREGAUTO. All currents sourced into the regulator loads flow through
this pin.
An appropriate reverse battery protection network consisting of a diode and capacitors is recommended.
4.2.4
VDDA, VSSA — Regulator Reference Supply Pins
Pins VDDA and VSSA
,
are used to supply the analog parts of the regulator.
Internal precision reference circuits are supplied from these signals.
A local decoupling capacitor between VDDA and VSSA according to the electrical specification is
required. Additionally a bigger tank capacitor is required on the 5 Volt supply network as well to ensure
Voltage regulator stability.
VDDA has to be connected externally to VDDX.
4.2.5
VDDX, VSSX— Pad Supply Pins
This supply domain is monitored by the Low Voltage Reset circuit.
A local decoupling capacitor between VDDX and VSSX according to the electrical specification is
required.
Summary of Contents for MC9S12VRP64
Page 16: ...MC9S12VRP Family Reference Manual Rev 1 3 16 NXP Semiconductors ...
Page 46: ...Device Overview S12VRP Series MC9S12VRP Family Reference Manual Rev 1 3 46 NXP Semiconductors ...
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Page 436: ...Supply Voltage Sensor BATSV2 MC9S12VRP Family Reference Manual Rev 1 3 436 NXP Semiconductors ...
Page 528: ...NVM Electrical Parameters MC9S12VRP Family Reference Manual Rev 1 3 528 NXP Semiconductors ...
Page 530: ...Package Information MC9S12VRP Family Reference Manual Rev 1 3 530 NXP Semiconductors ...
Page 531: ...Package Information MC9S12VRP Family Reference Manual Rev 1 3 NXP Semiconductors 531 ...
Page 532: ...Package Information MC9S12VRP Family Reference Manual Rev 1 3 532 NXP Semiconductors ...