Specifications

92 Intel

Atom™ processor CE4100 Ref# 420826

Platform Design Guide

Intel Confidential

8.1.1.3 Serial ATA AC Coupling Requirements

The Intel

Atom™ processor CE4100 requires AC coupling capacitors for both the Tx and Rx

SATA differential pairs, see Figure 8-1. The series capacitors may be

placed at any point on

the traces between the processor and the Serial ATA connector. The general place for these

AC capacitors is about 1 inch to the SATA. The distance between the processor and the

capacitor on the ‘P’ signal should be identical to the distance between the processor and the

capacitor on the ‘N’ signal for the same pair.

Table 8-2. AC Coupling Capacitor

Signal Name Capacitor Figure Notes

SATA_RXP SATA_RXN C = 12 nF ± 10% Figure 8-1 1

SATA_TXP SATA_TXN C = 12 nF ± 10% Figure 8-1 1

Note: It is recommended to use 402-size capacitors.

8.1.1.4 SATA_RBIAS Connection

It is recommended that the SATARBIAS pin be routed on the top layer to one end of a 750-

Ω ±1% resistor to ground. Place the resistor within 500 mils of the processor. Avoid routing

next to clock pins.

Figure 8-3. SATARBIAS Connection

Table 8-3. SATA_RBIAS Routing Guidelines for the 1080 Stack-up

Signal

Name

Impedance

Width (W)

Layer Length

Length

Matching

within Diff

Pair

Figure Notes

SATA_RBIAS

55 Ω ±10% 4 mils Micro strip

0–0.5” NA Figure 8-3