Power Up Sequence; On-Board Sequencing; Inter-Board Sequencing - GE SBC330 3U VPX Hardware Reference Manual

3.5 Power Up Sequence

Publication No. SBC330-0HH/3
The SBC330RTM has two options for serial I/O: a single mini‐DB9 connector that
hosts both COM1 and COM2 is provided, or via a 2x10‐way header suitable for
use with GEIP's SIOX600 ribbon to DB9 serial adapter.
COM1 is configured as DTE with default settings of 9600 baud, 8 bits/character, 1
stop bit, parity disabled and no flow control.
For the Ethernet ports, a CAT5 (or better) straight‐through patch cable for 10/100/
1000BaseTX.
TIP
The VPX I/O Modules Manual, publication number
fitting RTMs. Similar antistatic and safety precautions apply when handling and/or installing
I/O modules as for the SBC330.

3.5.1 On-board sequencing

Several components on the SBC330 receive multiple power supplies and require
PSU power‐up and power‐down sequencing. The actual sequence is described in
detail in later sections just for user information and possible debug of blue power
LEDs.
The SBC330 uses a Lattice 1014A ispPAC Power Manager device to sequence the
on‐board PSUs. The device also monitors the backplane supply voltages and only
turns on any on‐board supplies once the backplane voltage on VS3 is above 4.49
Volts.
If the Board Management Microcontroller (BMM) asserts the BMM_OFF signal,
the power manager will shut down all on‐board supplies (except VCC and
P3V3_AUX).
The power manager is connected to the on‐board I
read‐out of the voltages of all on and off‐board supplies.

3.5.2 Inter-board sequencing

The SBC330 supports inter‐board power sequencing, conforming to the GEIP
internal specification. This feature allows for different boards in a system to see
the power‐on condition at delayed times, reducing the surge loading/in‐rush
currents on the system backplane PSU. This is achieved by the PSU_SEQ_OUT
and PSU_SEQ_IN signals, which can be daisy‐chained between boards.
The SBC330 drives the PSU_SEQ_OUT signal low ('0') when the backplane
supplies are out of specification, and holds it low until all of the on‐board
supplies are running and within the firmware programmable limits. If the next
board in the rack does not power until it sees the signal go high, it will not load
the PSU until the power for the SBC330 has stabilized.
The SBC330 holds off all on‐board supplies when the PSU_SEQ_IN signal is held
low. The power‐on sequence is initiated if the PSU_SEQ_IN signal remains low
500ms after the off‐board supplies are within specification, which may occur if the
previous board in the chain fails.
VPXIOM-0HH, contains more details on
2
C Bus 2, allowing software
Installation and Power-Up 17