摘要 |
A selectively transparent interface circuit identified herein as a flow-through register (FTR) is disclosed. The FTR enables one or more devices on a primary bus to communicate with a device on a secondary bus without incurring the latency and performance degradation of conventional bridges. The FTR can also provide Hot Swap capability which allows, for example, a device designed for a regular PCI bus to be plugged into a CompactPCI bus while system power remains on. The synchronous flow-through nature of the FTR eliminates the need for large data buffers that would otherwise result in transaction delays and performance degradation. Unlike other types of non-transparent devices such as PCI-to-PCI bridges, the FTR does not occupy any configuration space and is fully transparent to the host and HBA device driver software during flow-through operation, eliminating the need for costly changes to host and device driver firmware/software.
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