GX4002 Datasheet, PDF (48/74 Pages) Gennum Corporation – Dynamic on-chip power management control

3.8 Power Control Options
The GX4002 provides a high-degree of flexibility in configuring the device for optimal
power through power-down and power adjustment registers. Typical usage scenarios
are shown. For further description on each of the individual control bits, see Table 7-1,
registers 134 to 137. This section describes the power-down controls for the following
sub-systems:
1. Ch1 CDR & SDO Power-Down
2. Ch0 CDR Power-Down
3. Ch0 SDO Power-Down
Table 3-7: Ch1 CDR & SDO Power-Down
Description
0
1
x
x
x
1
Completely powers-down the Ch1 CDR and Ch1 SDO.
0
x
1
x
x
1
Completely powers-down the Ch1 CDR and Ch1 SDO
1
0
x
x
x
0
Main data path through Ch1 CDR and Ch1 SDO is powered-up for bypass
mode. (Ch1LA has to be powered-up).
0
0
0
1
1
0
Mission mode, Ch1 CDR & SDO enabled in low-power mode.
0
0
0
1
1
0
Mission mode for fibre channel. Ch1 CDR & SDO are enabled with
automatic bypass through rate detection.
0
0
0
0
1
0
Diagnostic mode with horizontal eye monitor enabled.
0
0
0
1
0
0
Diagnostic mode with divided recovered clock available through Ch1 SDO.
Requires appropriate configuration of loopback registers.
Table 3-8: Ch0 CDR Power-Down
Description
0
1
1
x
x
1
Completely powers-down the Ch0 CDR
1
0
1
x
x
0
Main data path through Ch0 CDR is powered-up for bypass mode. (Ch0Eq
has to be powered-up).
0
0
0
1
1
0
Mission mode, Ch0 CDR is enabled in low power mode.
GX4002 2x2 14.025Gb/s Crosspoint Switch with Trace
Equalization and Output De-Emphasis
Data Sheet
55972 - 0
March 2012
48 of 74
Proprietary & Confidential