VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Information
Quad Port Bypass Circuit
VSC7124
Application Example
A 12-port JBOD is shown in Figure 1. This dual loop application uses one VSC7127R, one VSC7127T and one
VSC7124 on each loop in order to configure the FC-AL disk array. Functional drives are included in the FC-
AL loop while nonfunctional or missing drives (numbers 2, 7, 9) are excluded.
Figure 1: 12-Drive FC-AL JBOD Application
Optics
or
Copper
1
LOOP A
Retimer
0
1
Retimer
0
1
0
VSC7127T #6
7125
SerDes
7125
SerDes
1
VSC7127T #5
0
1
2
7125
SerDes
7125
SerDes
7125
SerDes
7125
SerDes
7125
SerDes
7125
SerDes
7125
SerDes
7125
SerDes
0
1
4
VSC7121 QUAD PORT BYPASS CIRCUIT
0
1
3
4
0
1
3
0
1
CONFIGURATION:
VSC7127R #1 & 2: Repeater Mode
SEL0=1, SEL5=1
MODE=0
VSC7124 #3 & 4: No CRU
VSC7127T #5 & 6: Retimer Mode
SEL1=1, SEL5=1
MODE=1
0
1
1
0
2
0
4
1
5
6
0
1
VSC7124 #4
0
1
VSC7124 #3
0
1
3
0
1
7
7125
SerDes
7125
SerDes
0
1
2
0
1
8
0
1
0
0
1
0
1
9
0
1
4
0
1
VSC7127R #2
0
1
3
VSC7127R #1
0
1
0
1
2
0
1
Optics
or
Copper
0
1
1
7125
SerDes
7125
SerDes
7125
SerDes
7125
SerDes
7125
SerDes
7125
SerDes
10
11
12
LOOP B
Repeater
0
Repeater
Page 2
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VITESSE
SEMICONDUCTOR CORPORATION
• 741 Calle Plano • Camarillo, CA 93012
Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com
Internet: www.vitesse.com
G52293-0, Rev 2.3
5/7/01
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
