ICS1893BF Data Sheet Rev. E - Release
Chapter 4 Operating Modes Overview
4.1 Reset Operations
This section first discusses reset operations in general and then specific ways in which the ICS1893BF can
be configured for various reset options.
4.1.1 General Reset Operations
The following reset operations apply to all the specific ways in which the ICS1893BF can be reset, which
are discussed in Section 4.1.2, “Specific Reset Operations”.
4.1.1.1 Entering Reset
When the ICS1893BF enters a reset condition (either through hardware, power-on reset, or software), it
does the following:
1. Isolates the MAC Interface input pins
2. Drives all MAC Interface output pins low
3. Tri-states the signals on its Twisted-Pair Transmit pins (TP_TXP and TP_TXN)
4. Initializes all its internal modules and state machines to their default states
5. Enters the power-down state
6. Initializes all internal latching low (LL), latching high (LH), and latching maximum (LMX) Management
Register bits to their default values
4.1.1.2 Exiting Reset
When the ICS1893BF exits a reset condition, it does the following:
1. Exits the power-down state
2. Latches the Serial Management Port Address of the ICS1893BF into the Extended Control Register,
bits 16.10:6. [See Section 7.11.3, “PHY Address (bits 16.10:6)”.]
3. Enables all its internal modules and state machines
4. Sets all Management Register bits to their default values
5. Enables the Twisted-Pair Transmit pins (TP_TXP and TP_TXN)
6. Resynchronizes both its Transmit and Receive Phase-Locked Loops, which provide its transmit clock
(TXCLK) and receive clock (RXCLK)
7. Releases all MAC Interface pins, which takes a maximum of 640 ns after the reset condition is removed
4.1.1.3 Hot Insertion
As with the ICS189X products, the ICS1893BF reset design supports ‘hot insertion’ of its MII. (That is, the
ICS1893BF can connect its MAC Interface to a MAC while power is already applied to the MAC.)
ICS1893BF, Rev. E, 8/11/09
August, 2009
Copyright © 2009, IDT, Inc.
All rights reserved.
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