ICS1893 Datasheet, PDF (102/152 Pages) Integrated Circuit Systems – 3.3-V 10Base-T/100Base-TX Integrated PHYceiver™

ICS1893 Data Sheet - Release
Chapter 8 Management Register Set
8.14.5 Twisted Pair Tri-State Enable, TPTRI (bit 19.7)
The ICS1893 provides a Twisted Pair Tri-State Enable bit. This bit forces the TP_TXP and TP_TXN signals
to a high-impedance state. When this bit is set to logic:
• Zero, the Twisted Pair Interface is operational.
• One, the Twisted Pair Interface is tri-stated.
8.14.6 ICS Reserved (bits 19.12:6)
See Section 8.11.2, “ICS Reserved (bits 16.14:11)”, the text for which also applies here.
8.14.7 Force LEDs On (bit 19.5)
Each ICS1893 provides a Force LEDs On bit as a diagnostic function. This bit overrides the normal
operation of the LEDs and forces them on. When this bit is set to logic:
• Zero, the normal operation of all ICS1893 LEDs is unaffected.
• One, all ICS1893 LEDs forced on.
Note: The ‘on’state of the LEDs driven from multi-function configuration pins is determined after the pin
is sampled.
8.14.8 ICS Reserved (bits 19.4:1)
See Section 8.11.2, “ICS Reserved (bits 16.14:11)”, the text for which also applies here.
8.14.9 Automatic 100Base-TX Power-Down (bit 19.0)
The Automatic 100Base-TX Power Down bit provides an STA with the means of enabling the ICS1893 to
automatically shut down 100Base-TX support functions when 10Base-T operations are being used. When
this bit is set to logic:
• Zero, the 100Base-TX Transceiver does not power down automatically in 100Base-TX mode.
• One, and the ICS1893 is operating in 10Base-T mode, the 100Base-TX Transceiver automatically turns
off to reduce the overall power consumption of the ICS1893.
Note: There are other means of powering down the 100Base-TX Transceiver (for example, when the
entire device is isolated using bit 0:10).
ICS1893 Rev C 6/6/00
Copyright © 2000, Integrated Circuit Systems, Inc.
All rights reserved.
102
June, 2000