Specifications

66 Intel
®
Atom™ processor CE4100 Ref# 420826
Platform Design Guide
Intel Confidential
5.8 Miscellaneous Signals Design
Guidelines
The DDR2/3 interface has two calibration balls: RCOMPPU, RCOMPPD.
RCOMPPD should be connected through external 80.6 Ω ± 1% calibration resistors to GND.
RCOMPPU must be connected through external 80.6 Ω ± 1% calibration resistors to DDR
power well.
Please match RCOMPPU and RCOMPPD traces inter and intra channel to 3mm. Please keep
the trace length under 30mm to minimize the added resistance.
The Intel
®
Atom™ processor CE4100 monitors the outputs of these balls to dynamically
adjust the slew rate and drive strength to compensate for temperature and voltage
variation. The circuits should be located close to the processor package.
Figure 5-14. RCOMPPD Connection
Figure 5-15. RCOMPPU Connection