Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
605
DDR SDRAM Memory Controller—Intel
®
81341 and 81342
The DMCU supports optimized performance for random address transactions. This
optimization eliminates the need of the DDR SDRAM Control Block to issue the
transaction command to the DDR array when the previous transaction is the same type
(read or write). In addition, the DDR SDRAM Control Block supports pipelining of
transactions which allows the column address of the next transaction to be issued
before the current transaction’s data transfer is completed by the DDR SDRAM devices.
These optimizations are illustrated in
for random write memory transactions
.
Figure 90. DDR SDRAM Pipelined Writes
B0408-01
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
Command
CK#
CK
Write
Write
Write
Write
Write
Address
Bank
Col b
Bank
Col x
Bank
Col n
Do
b
Do
b'
Do
x
Do
x'
Do
n'
Do
a
Do
a'
Do
n
Bank
Col a
Bank
Col g
ADDRESS Max
DQS
DI vs Do
DM
= Don't Care
Notes:
- DI b, etc. = Data In for column b, etc.
- DI b', etc. = the next Data in following DI b, etc. according to the programmed burst order
- Burst Length = 4 is shown.
- Write command may be to any bank and may be in the same or different devices.