Visible to Intel only — GUID: iga1405375298687
Ixiasoft
Visible to Intel only — GUID: iga1405375298687
Ixiasoft
33.2.1. Avalon® memory-mapped interface
The Avalon® memory-mapped interface agent port is the user-visible part of the SDRAM controller core. The agent port presents a flat, contiguous memory space as large as the SDRAM chip(s). When accessing the agent port, the details of the PC100 SDRAM protocol are entirely transparent. The Avalon® memory-mapped interface interface behaves as a simple memory interface. There are no memory-mapped configuration registers.
The Avalon® memory-mapped interface agent port supports peripheral-controlled wait states for read and write transfers. The agent port stalls the transfer until it can present valid data. The agent port also supports read transfers with variable latency, enabling high-bandwidth, pipelined read transfers. When a host peripheral reads sequential addresses from the agent port, the first data returns after an initial period of latency. Subsequent reads can produce new data every clock cycle. However, data is not guaranteed to return every clock cycle, because the SDRAM controller must pause periodically to refresh the SDRAM.
For details about Avalon® memory-mapped interface transfer types, refer to the Avalon® Interface Specifications.