Intel
®
81341 and 81342—DDR SDRAM Memory Controller
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
566
Order Number: 315037-002US
7.3.1.1
Transaction Ports
The DMCU provides six transaction ports for direct DDR SDRAM access. The ports are
described in the following sub-sections.
7.3.1.1.1
North Internal Bus Port
The North IB Port provides the 81341 and 81342 processor core access to the Memory
Controller. This North IB Port allows core transactions targeting the DDR SDRAM via the
North IB bus to pass directly to the DDR SDRAM.
7.3.1.1.2
South Internal Bus Port
The South IB Port provides the connection to the DDR SDRAM from the South IB Bus.
Peripheral unit transactions targeting the DDR SDRAM are claimed by this port. For
example, the ATU transactions are claimed by the South IB port. Note that the
Application DMAs connect to the DDR SDRAM directly using other DMCU ports.
7.3.1.1.3
Application DMA Ports
The Application DMAs connect to the DMCU using dedicated ports — Application DMA
ports. There are three Application DMAs. The Application DMA can transfer data
between DDR SDRAM or between DDR SDRAM and South IB agents.
7.3.1.1.4
Messaging Unit Port
The Messaging Unit (MU) connects to the DMCU using a dedicated port. From an
application point of view, the MU is used in conjunction with the ATU.