ICS1892
TSD
Chapter 5 Operating Modes Overview
10Base-T/100BIaCseS-TX1I8nt9eg2rated PHYceiver™
5.3 Automatic Power-Saving Operations
The ICS1892 has power-saving features that automatically minimize its total power consumption while it is
operating. Table 5-1 lists the ICS1892 automatic power-saving features for the various modes.
Table 5-1. Automatic Power-Saving Features, 10Base-T and 100Base-TX Modes
Power-
Saving
Feature
Mode for ICS1892
10Base-T Mode
100Base-TX Mode
Disable Inter- In 10Base-T mode, the ICS1892 disables
nal Modules all its internal 100Base-TX modules.
In 100Base-TX mode, the ICS1892
disables all its internal 10Base-T modules.
STA Control When an STA sets the state of the ICS1892 When an STA sets the state of the ICS1892
of Automatic Extended Control Register 2, bit 19.0 to
Extended Control Register 2, bit 19.1 to
logic:
• Zero, the 10Base-T modules always
remain enabled, even during
100Base-TX operations.
Power-
Saving
logic:
• Zero, the 100Base-TX modules always
remain enabled, even during 10Base-T
operations.
Features
• One, the ICS1892 automatically
disables 100Base-TX modules while the
ICS1892 is operating in 10Base-T
mode.
• One, the ICS1892 automatically
disables 10Base-T modules while the
ICS1892 is operating in 100Base-TX
mode.
5.4 Auto-Negotiation Operations
The ICS1892 has an Auto-Negotiation sublayer. It provides both an input pin, ANSEL (Auto-Negotiation
Select) and a Control Register bit (bit 0.12) to determine whether its Auto-Negotiation sublayer is enabled
or disabled. The ICS1892 HW/SW input pin exclusively selects whether the ANSEL pin (which is used for
the hardware mode) or Control Register bit 0.12 (which is used for the software mode) controls its
Auto-Negotiation sublayer.
When enabled, the ICS1892 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 ICS1892 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 7.2, “Functional Block: Auto-Negotiation”.
ICS1892, Rev. D, 2/26/01
February 26, 2001
© 2000-2001, Integrated Circuit Systems, Inc.
All rights reserved.
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IDT™ / ICS™ 10Base-T/100Base-TX Integrated PHYceiver™
ICS1892
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IDT [ INTEGRATED DEVICE TECHNOLOGY ]
