ocr: 2115A Granes 2154 So X1 EXSA tdge on - courcers lar aecavedet Figure 21 Digital Semiconductor's 21154 64-bit PCI bridge chip allows for expansion of system capacity: via the addition of more: PCI devices. ar PCI option card slots than a single PCI bus can: support.The 21154 chip has more: buffering capacity than first-generation bridges.