Table of Contents
Advertisement
PCI-946-1 and P3S440BX Technical Reference manual
3.4.6. 21554 PCI-to-PCI Bridge
The 21554 is a PCI peripheral chip that performs PCI bridging functions for embedded and
intelligent I/O applications. The 21554 is a "non-transparent" PCI-to-PCI bridge that acts
as a gateway to an intelligent subsystem. It allows a local processor to independently
configure and control the local subsystem. The 21554 implements an I
O message unit that
2
enables any local processor to function as an intelligent I/O processor (IOP) in an I
O-
2
capable system.
Unlike a transparent PCI-to-PCI bridge, the 21554 is specifically designed to bridge
between two processor domains. The processor domain on the primary interface of the
21554 is also referred to as the host processor. The secondary bus interfaces to the local
domain and the local processor. Special features include support of independent primary
and secondary PCI clocks, independent primary and secondary address spaces, and address
translation between primary (host) and secondary (local) domains.
The 21554 supports a 64-bit primary PCI bus, a 64-bit secondary PCI bus, and a maximum
operation frequency of 33MHz.
3.4.7. 82371AB PCI-to-ISA Bridge / IDE Xcelerator (PIIX4)
The PCI-to-ISA bridge is configured to support signals to directly drive IDE interfaces,
USB ports, and standard Serial Ports (1 and 2), floppy disk drives, mouse and keyboard
through a super I/O controller (FDC37C672).
3-12
Downloaded from StockCheck.com
Advertisement
Table of Contents
