Motorola CPCI-6020 manual Onboard Power Supplies, Board Reset Logic

Onboard Power Supplies Functional Description

4.10.3Onboard Power Supplies

The CPCI-6020 requires +5 V, +3.3 V, +1.8 V and +/-12 V (optional) input voltages. The processor core voltage and +2.5 V for the Harrier core are generated on board from the +5 V input by switching regulators. The processor core voltage regulator has a variable output which is set using feedback resistors. In addition to the Harrier core voltage, the +2.5 V supply will provide the processor, Harriers and L2 cache I/O voltage when the MPC7410 processor is used. Power resistors installed during assembly will select either +3.3 V or +2.5 V to supply the I/O voltage for the processor, Harriers and the L2 cache. +1.8 V is generated using an onboard regulator through +3.3 V.

4.10.4Board Reset Logic

A block diagram of the CPCI-6020 board reset logic is shown below. The board reset logic is implemented in a programmable logic device (PLD) in order to provide maximum flexibility of the circuit design.

There are several potential sources of reset on the CPCI-6020. They are:

zPower-on/under voltage reset

zFront panel reset switch

zCompactPCI PRST#

zWatchdog Timer reset via Harrier A WDT2

zCompactPCI FAL# signal

zSoftware generated hard reset via the Harrier RSTOUT bit

zSoftware generated hard reset via the Port 92 Register in the PBC

zCompactPCI Bus reset via the 21154 Bridge Control Register

zProcessor RISCWatch JTAG emulator interface HRESET# signal (open collector)

CPCI-6020 CompactPCI Single Board Computer Installation and Use (6806800A51C) 95