Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
565
DDR SDRAM Memory Controller—Intel
®
81341 and 81342
7.3
Theory of Operation
The 81341 and 81342 memory controller translates transactions from the North
internal bus, South internal bus, the Application DMAs (ADMA), and the Messaging Unit
into the protocol supported by the DDR2 SDRAM memory subsystem.
7.3.1
Functional Blocks
The memory controller logically comprises the blocks illustrated in
. The
memory controller is a multi-ported unit, supporting inbound paths from the north
internal bus, the south internal bus, the Application DMAs to the DDR2 SDRAM.
Figure 78. Memory Controller Block Diagram
Configuration
Registers
South IB
Address
Decode
DDR II
SDRAM
North Internal Bus
North IB
Address
Decode
DDR- II SDRAM
Control
South IB Port
Transaction
Queue
North IB Port
Transaction
Queue
DDR MCU
South Internal Bus
MARB
Messaging
Unit
Application
DMA 0
Application
DMA 1
Application
DMA 2
Intel
XScale®
processor
Intel
XScale®
processor
B6253-01