Intel
®
81341 and 81342—DDR SDRAM Memory Controller
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
602
Order Number: 315037-002US
The timing parameters and protocol for all non-read and non-write commands are
derived directly from the JEDEC Standard Double Data Rate (DDR) SDRAM
Specification JESD79, June 200 and JEDEC DDR — II SDRAM Specification, September
2002. Please see the JEDEC specification for the timing parameters specific to the DDR
device that is to be implemented in the system.
Note:
Burst Length (BL) is fixed at four for 81341 and 81342
Figure 89. DMCU Active, Precharge, Refresh Command Timing Diagram
m_clk
tRC
tRAS
Notes:
tRC = Active to Active, Active to Refresh
tRFC = Refresh to Active, Refresh to Refresh
tRP = Precharge Command Period
tRAS = Active to Precharge
tRCD = Active to Read, Active to Write
ACT or ARF
tRFC
Next command
ACT or ARF
tRP
tRCD
Read or Write
t0
tn tn+1
tn+2
tn+3
tn+4
B6262-01
A
A
A
A
A
A
A
A
A/A
ACT
PCH
R/W
CMD
PCH
A/A
ARF