System Memory Design Guidelines (DDR-SDRAM)
R
Intel
®
855PM Chipset Platform Design Guide
159
6.1.7.1.2.
Additional Design Considerations for Adapting Intel 855PM DDR 200/266 MHz
Platforms To Support PC2700
In addition to meeting the updated routing length requirements specified in Section 6.2.7.1, future DDR
333-MHz platforms must also adhere to all other existing design guidelines for the DDR 200-MHz and
266-MHz platforms. Table34 contains section references to all other existing design guidelines that need
to be followed for the different signal groups.
Table 34. Existing PC2100/PC1600 DDR SDRAM Design Guidelines Required for PC2700 Support
Group Signal
Section
Reference
Data SDQ[71:0];
SDQS[8:0] 6.2.1
Control SCKE[3:0];
SCS#[3:0] 6.2.2
Command
SMA[12:0]; SBS[1:0]; SRAS#; SCAS#; SWE#
6.2.3
Clock SCK[5:0];
SCK#[5:0] 6.2.4
Feedback RCVENOUT#;
RCVENIN# 6.2.5
