VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
10-Bit Transceiver for Fibre
Channel and Gigabit Ethernet
VSC7123
Figure 6: REFCLK Timing Waveforms
TH
TL
VIH(MIN)
VIL(MAX)
REFCLK
TF
TR
Table 4: Reference Clock Requirements
Parameter
Description
Frequency Range
Min
Max Units
Conditions
Range over which both transmit and
receive reference clocks on any link may
be centered.
FR
98
136
200
MHz
ppm
Maximum frequency offset between
transmit and receive reference clocks on
one link.
FO
Frequency Offset
-200
DC
REFCLK duty cycle
35
65
%
ns
Measured at 1.5V
TR,TF
REFCLK rise and fall time
—
1.5
Between VIL(MAX) and VIH(MIN)
© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012
Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com
Internet: www.vitesse.com
Page 8
G52212-0, Rev 4.3
03/25/01