ICS1893Y-10 Datasheet, PDF (23/150 Pages) –

ICS1893Y-10 - Release
Chapter 4 Operating Modes Overview
4.3 Automatic Power-Saving Operations
The ICS1893Y-10 has power-saving features that automatically minimize its total power consumption while
it is operating. Table 4-1 lists the ICS1893Y-10 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 ICS1893Y-10
10Base-T Mode
100Base-TX Mode
Disable Inter- In 10Base-T mode, the ICS1893Y-10
nal Modules disables all its internal 100Base-TX
modules.
In 100Base-TX mode, the ICS1893Y-10
disables all its internal 10Base-T modules.
STA Control
of Automatic
Power-
Saving
Features
When an STA sets the state of the
ICS1893Y-10 Extended Control Register 2,
bit 19.0 to logic:
• Zero, the 100Base-TX modules always
remain enabled, even during 10Base-T
operations.
• One, the ICS1893Y-10 automatically
disables 100Base-TX modules while the
ICS1893Y-10 is operating in 10Base-T
mode.
When an STA sets the state of the
ICS1893Y-10 Extended Control Register 2,
bit 19.1 to logic:
• Zero, the 10Base-T modules always
remain enabled, even during
100Base-TX operations.
• One, the ICS1893Y-10 automatically
disables 10Base-T modules while the
ICS1893Y-10 is operating in
100Base-TX mode.
4.4 Auto-Negotiation Operations
The ICS1893Y-10 has an Auto-Negotiation sublayer and 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 ICS1893Y-10 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 ICS1893Y-10 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 ICS1893Y-10 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”.
ICS1893Y-10 Rev F 1/20/04
Copyright © 2004, Integrated Circuit Systems, Inc.
All rights reserved.
23
January, 2004