Intel® E8870 Scalable Node Controller (SNC) Datasheet
Overview: The Intel® E8870 chipset delivers new levels of availability, features, and performance for servers. It provides flexible common modular architecture support for the Intel® Itanium® 2 processors. The Intel E8870 chipset supports up to four processors, and up to eight processors with the Scalability Port Switch (SPS).
The supply network capability (SNC) is the processor system bus interface and memory controller for the Intel E8870 chipset. It supports the Itanium® 2 processors, DDR SDRAM main memory, a firmware hub interface to support multiple firmware hubs, two scalability ports (SPs) for access to I/O, and coherent memory on other nodes.
The SNC may be connected to an SPS for scaling to large systems. The SNC is connected directly to a Server Input/Output Hub (SIOH) for single-node system implementations.
The local access transaction tracker (LATT) is a buffer that holds processor requests until they are completed. The LATT then converts processor requests into scalability port (SP) requests, which it inserts into the SP Request Out Queue for SP0 or SP1. The response returns in the SP Response In Queue on the same SP. The LATT picks a request from one SP or the other, and sends it to the processor system bus interface. The remote access transaction tracker (RATT) pulls SP requests from the SP Request In Queue from one SP or the other. The request is stored in the RATT until completed. Requests entering the SNC are presented to Conflict Resolution logic one at a time to resolve coherency races. If a request is to the same address as a request already stored in the LATT or RATT, Conflict Resolution logic blocks progress of one request or another until ordering is resolved.
Read the full Intel® E8870 Scalable Node Controller (SNC) Datasheet.