Emerson MVME7100 manual XMC Expansion, Power Supplies, Clock Distribution, Power Sequencing

XMC Expansion Functional Description

4.11XMC Expansion

The MVME7100 provides an additional XMC/PMC module capability through the use of a 78- pin stacking connector. This connector is connected to the second PCI Express port on the processor. Up to four additional XMC/PMC modules may be added by using two expansion boards. Refer to the XMCspan datasheet for additional details and/or programming information.

4.12Power Supplies

The MVME7100 on-board voltages will be generated using Linear Tech LTC3828 dual output two phase controllers and LTC3416 single output controllers. The following sections detail the MVME7100 power requirements.

4.12.1Power Sequencing

In order to meet the power sequencing requirements of the various components on the MVME7100, the power supply controllers implement voltage tracking which allows the power supply outputs to track each other coincidentally during power up and power down. The +3.3 V supply output will be used as the tracking reference. All supply outputs will reach their final values within 20 milliseconds during power up.

4.12.2Power Supply Monitor

Logic is provided on-board to monitor the PGOOD signal from the LTC3828 and LTC3416 regulators to determine if the power supply outputs are within tolerance. If any of the power supplies fail, this logic shuts off the power supplies to avoid any component damage. If the +5.0 V power supply is still good during a fail condition, a planar red LED (PWR FAIL D9) is illuminated to indicate the power supply fail condition.

4.12.3Power Supply Filtering and Fusing

Each of the switching power supply inputs on the MVME7100 will have an inductor to reduce switching noise from being fed back onto the +5.0 V input. The LTC3828 supplies will each have a 10 A fuse to protect the supplies from over-current in case of component failure.

4.13Clock Distribution

The clock function generates and distributes all of the clocks required for system operation. The PCI-E clocks are generated using an eight output differential clock driver. The PCI/PCI-X bus clocks are generated by the bridge chips from the PCI-E clock. Additional clocks required by individual devices are generated near the devices using individual oscillators. For clock assignments, refer to the MVME7100 Single Board Computer Programmer’s Reference manual.

MVME7100 Single Board Computer Installation and Use (6806800E08A) 73