1893CFLFT IDT, 1893CFLFT Datasheet - Page 12

• Manufacturer Part Number: 1893CFLFT
• Description: Ethernet ICs 3.3V 10/100 BASE TX INTEGRATED PHYCEIVER
• Manufacturer: IDT

Specifications of 1893CFLFT

• Rohs: yes
• Part # Aliases: ICS1893CFLFT

4.1.2.3 Software Reset
4.2 Power-Down Operations
ICS1893CK-40, Rev. C, 06/02/09
Entering Software Reset
Initiation of a software reset occurs when a management entity writes a logic one to Control Register bit
0.15. When this write occurs, the ICS1893CK-40 enters the reset state for two REF_IN clock cycles.
Note:
Exiting Software Reset
At the completion of a reset (either hardware, power-on, or software), the ICS1893CK-40 sets all registers
to their default values. This action automatically clears (that is, sets equal to logic zero) Control Register bit
0.15, the software reset bit. Therefore, for a software reset (only), bit 0.15 is a self-clearing bit that indicates
the completion of the reset process.
Note:
1. The RESETn pin is active low but Control Register bit 0.15 is active high.
2. Exiting a software reset is nearly identical to exiting a hardware reset or a power-on reset, except that
3. The Control Register bit 0.15 does not represent the status of a hardware reset. It is a self-clearing bit
The ICS1893CK-40 enters the power-down state whenever either (1) the RESETn pin is low or (2) Control
Register bit 0.11 (the Power-Down bit) is logic one. In the power-down state, the ICS1893CK-40 disables
all internal functions and drives all MAC Interface output pins to logic zero except for those that support the
MII Serial Management Port. In addition, the ICS1893CK-40 tri-states its Twisted-Pair Transmit pins
(TP_TXP and TP_TXN) to achieve an additional reduction in power.
There is one significant difference between entering the power-down state by setting Control Register bit
0.11 as opposed to entering the power-down state during a reset. When the ICS1893CK-40 enters the
power-down state:
•
•
For more information on power-down operations, see the following:
•
•
By setting Control Register bit 0.11, the ICS1893CK-40 maintains the value of all Management Register
bits except for the latching low (LL), latching high (LH), and latching maximum (LMX) status bits. Instead,
these LL, LH, and LMX Management Register bits are re-initialized to their default values.
During a reset, the ICS1893CK-40 sets all of its Management Register bits to their default values. It does
not maintain the state of any Management Register bit.
Section 7.14, “Register 19: Extended Control Register 2”
Section 9.4, “DC Operating
consumption while in the power-down state
upon exiting a software-initiated reset, the ICS1893CK-40 does not re-latch its Serial Management Port
Address into the Extended Control Register. [For information on the Serial Management Port Address,
see
that is used to initiate a software reset. During a hardware or power-on reset, Control Register bit 0.15
does not get set to logic one. As a result, this bit 0.15 cannot be used to indicate the completion of the
reset process for hardware or power-on resets.
Entering a software reset is nearly identical to entering a hardware reset or a power-on reset,
except that during a software-initiated reset, the ICS1893CK-40 does not enter the power-down
state.
Section 7.11.3, “PHY Address (bits
ICS1893CK-40 Data Sheet - Release
Copyright © 2009, Integrated Device Technology, Inc.
Characteristics”, which has tables that specify the ICS1893CK-40 power
16.10:6)”.]
All rights reserved.
12
Chapter 4 Operating Modes Overview
June 2009