UltraSPARC-II CPU Module

Advanced Version

400 MHz CPU, 4.0 MB E-Cache

SME5224AUPA-400

UPA Data Bus SPICE Model

A typical circuit for the UPA data bus and ECC signals is illustrated in Figure 4:.

Edge Connector

UDB-II Driver

Trace 1

3.1 nH

Trace 2

1.0 pF 1.0 pF

via 0.6 pF

7 pF

0.5 nH 50 Ω 2 nH

Edge Connector

3.1 nH

Trace 3

1.0 pF 1.0 pF

Measure point for XB1

Trace 4

via 0.6 pF

0.5 nH 50 Ω

XB1 BGA Package Loading

Measure point for CPU

7 pF

2 nH

UDB-II of Second Module

Package Loading

Worst Case: Z0 = 60Ω, TP = 180 ps/inch, Trace 1 Length = 4.4”, Trace 2 Length = 0.6”, Trace 3 Length = 1.2”, Trace 4 Length = 4.4”

Best Case: Z0 = 50Ω, TP = 160 ps/inch, Trace 1 Length = 2.2”, Trace 2 Length = 0.2”, Trace 3 Length = 0.2”, Trace 4 Length = 2.2”

Figure 4. Module System Loading: Example for UPA_DATA, UPA_ECC

July 1999

Sun Microsystems, Inc

13

Page 13
Image 13
Sun Microsystems SME5224AUPA-400 manual UPA Data Bus Spice Model, Module System Loading Example for UPADATA, Upaecc