Triple-Port PCI-To-PCI Bridge Increases Support For System Expansion Slots

摘要

Designers building telecom and datacom equipment crave PCI expansion slots. In their minds, more slots mean more line interface cards for their systems. The PCI bus, while restricted in the number of expansion slots it can support, can be easily expanded with one or more PCI-to-PCI bridge chips. The only problem is that standard bridge chips can limit a system's performance. To address this performance issue, Pericom Semiconductor has come up with a new kind of bridge chip. Instead of designing just another two-port bridge like its competitors, the company decided to add some value. The result was the PI7C7100-a triple-port PCI-to-PCI bridge that integrates two PCI-to-PCI bridges into a single bridge device. There are definite advantages to having an integrated three-port bridge system rather than two separate dual-port bridges. For example, only one package is needed as opposed to two, saving board real estate. Another bonus is that there's less routing involved. The main benefit, however, is performance (Fig. 1). Here's why.