User`s manual

HARDWARE PREPARATION AND INSTALLATION
MPC505EVBUM/D 2-7
2.2.4 Keep Alive Power 2 Select Header (J4)
Jumper header J3 provides power to the MCU-internal oscillator, time base, and decementer
modules via the MCU VKAPWR1 pin. You may use either the on-board +3.3 Vdc (jumper on J4
pins 1 and 2) or connect an external +3.3 Vdc power supply to J4 pins 2 and 3. An external +3.3
Vdc power supply on J4 pins 2 and 3 will maintain MCU-internal RAM data after EVB power is
turned OFF. To attach an external power supply to VKAPWR1: remove the jumper on J4 pins 1
and 2, and connect the power supply ground to J4 pin 3 and +3.3 Vdc to pin 2.
CAUTION
Applying power to the EVB with J4 removed and no external
power supply attached to J4 will damage the MPC505 MCU.
Always keep a jumper or an external +3.3 Vdc power supply on J4
pins 1 and 2. If using an external power supply, apply VKAPWR1
before powering up the EVB.
2.2.5 Burst Memory Select Header (J5)
Unused.