ICS1893BF Data Sheet - Release
Chapter 4 Operating Modes Overview
4.3 Automatic Power-Saving Operations
The ICS1893BF has power-saving features that automatically minimize its total power consumption while it
is operating. Table 4-1 lists the ICS1893BF automatic power-saving features for the various modes.
Table 4-1. Automatic Power-Saving Features, 10Base-T and 100Base-TX Modes
Power-
Saving
Feature
Mode for ICS1893BF
10Base-T Mode
100Base-TX Mode
Disable Inter- In 10Base-T mode, the ICS1893BF
nal Modules disables all its internal 100Base-TX
modules.
In 100Base-TX mode, the ICS1893BF
disables all its internal 10Base-T modules.
STA Control When an STA sets the state of the
of Automatic ICS1893BF Extended Control Register 2,
When an STA sets the state of the
ICS1893BF Extended Control Register 2,
bit 19.1 to logic:
• Zero, the 10Base-T modules always
remain enabled, even during
100Base-TX operations.
Power-
Saving
Features
bit 19.0 to logic:
• Zero, the 100Base-TX modules always
remain enabled, even during 10Base-T
operations.
• One, the ICS1893BF automatically
disables 100Base-TX modules while the
ICS1893BF is operating in 10Base-T
mode.
• One, the ICS1893BF automatically
disables 10Base-T modules while the
ICS1893BF is operating in 100Base-TX
mode.
4.4 Auto-Negotiation Operations
The ICS1893BF has an Auto-Negotiation sublayer and provides a Control Register bit (bit 0.12) to
determine whether its Auto-Negotiation sublayer is enabled or disabled.
When enabled, the ICS1893BF Auto-Negotiation sublayer exchanges technology capability data with its
remote link partner and automatically selects the highest-performance operating mode it has in common
with its remote link partner. For example, if the ICS1893BF supports 100Base-TX and 10Base-T modes –
but its link partner supports 100Base-TX and 100Base-T4 modes – the two devices automatically select
100Base-TX as the highest-performance common operating mode. For details regarding initialization and
control of the auto-negotiation process, see Section 6.2, “Functional Block: Auto-Negotiation”.
ICS1893BF, Rev. E, 8/11/09
August, 2009
Copyright © 2009, IDT, Inc.
All rights reserved.
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