M440LX Server System Product Guide 185
I/O Ports and Connectors 9

Signal States

In all tables in this chapter, active-low signal names have an “_L” symbol
following the name; for example, P_REQ_SLOT0_L. Active-high signal
names do not have a “_L” suffix.

Server System Board

The system board contains both PCI and ISA I/O systems with several
embedded devices for video, network, and disk control. The board also
provides
• server management/monitoring hardware support
• interrupt control (I/O APIC and standard PC)
• a primary PCI bus segment (PCI-0) with four expansion connectors and
two embedded devices
• an ISA bus segment with three expansion connectors (one physically
shared with PCI-0)
• a National Semiconductor Super I/O chip providing all PC-compatible
I/O and Xbus interfaces