PMC-8246 is a high-performance 2-port Gigabit Ethernet (GbE) PCI-X PMC module providing bypass capability, which can connect GbE signals on the two GbE connectors while the system is powered down or under software halt.
The PMC-8246 is based on the Intel 82546GB dual-port Gigabit Ethernet controller. The Intel 82546GB is a highly integrated chip, includes Ethernet MAC, and PHY, and provides PCI-X 133MHz capability. Please refer to the Intel 82546GB datasheet for more information on the GbE ports.
The PMC-8246’s bypass capability uses a mechanical relay array to control the physical routing of the GbE signals. There are two communications states for the GbE signal routing: 1) Normal State, 2) Bypass State. Please refer to section 1.4 for block diagrams of the two states.
Watchdog timer (WDT) and bypass control logic circuits are used to control the relay and communication states. The programmer can control those functions via the Software Definable Pins (SDP) on the Intel 82546GB by programming its registers. Please refer to section 1.5 for a block diagram of the bypass control circuits.