ICS1893AGLF View Datasheet(PDF) - Integrated Circuit Systems
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'ICS1893AGLF' PDF : 135 Pages View PDF
ICS1893AG Data Sheet - Preliminary
Chapter 7 Functional Blocks
7.5.9 10Base-T Operation: Jabber
The ICS1893AG has an ISO/IEC compliant Jabber Detection Function that, when enabled, monitors the
data stream sent to its Twisted-Pair Transmitter to ensure that it does not exceed the 10Base-T Jabber
activation time limit (that is, the maximum transmission time). For more information, see Section 10.5.18,
“10Base-T: Jabber Timing”.
When the Jabber Detection Function detects that its transmission time exceeds the maximum Jabber
activation time limit and Jabber Detection is enabled, the ICS1893AG asserts its Collision Detect (COL)
signal. During this ISO/IEC specified ‘jabber de-activation time’, the ICS1893AG transmit data stream is
interrupted and prevented from reaching its Twisted-Pair Transmitter. During this time, when interrupting
the data stream and asserting its COL signal, the ICS1893AG transmits Normal Link Pulses and sets its
QuickPoll Detailed Status Register’s Jabber Detected bit (bit 17.2) to logic one. This bit is a latching high
(LH) bit. (For more information on latching high and latching low bits, see Section 8.1.4.1, “Latching High
Bits” and Section 8.1.4.2, “Latching Low Bits”.)
The ICS1893AG provides an STA with the ability to disable the Jabber Detection Function using the Jabber
Inhibit bit (bit 18.5 in the 10Base-T Operations Register). Setting bit 18.5 to logic:
• Zero (the default) enables the Jabber Detection Function.
• One disables the Jabber Detection Function.
7.5.10 10Base-T Operation: SQE Test
The ICS1893AG has an ISO/IEC compliant Signal Quality Error (SQE) Test Function used exclusively for
10Base-T operations. When enabled, the ICS1893AG performs the SQE Test at the completion of each
transmitted packet (that is, whenever its TX_EN signal transitions from asserted to de-asserted). When the
ICS1893AG executes its SQE Test, it asserts the COL signal to its MAC Interface for a pre-determined time
duration (ISO/IEC specified). [For more information, see Section 10.5.17, “10Base-T: Heartbeat Timing
(SQE)”.]
An ICS1893AG SQE Test Function is:
• Enabled only when all the following conditions are true:
– The ICS1893AG is in node mode.
– The ICS1893AG is in half-duplex mode.
– The ICS1893AG has a valid link.
– The 10Base-T Operations Register’s SQE Test Inhibit bit (bit 18.2) is logic zero (the default).
– The ICS1893AG TX_EN signal has transitioned from asserted (high) to de-asserted (low).
• Disabled whenever any of the following are true:
– The ICS1893AG is in Repeater mode.
– The ICS1893AG is in full-duplex mode.
– The ICS1893AG detects a link failure.
– The ICS1893AG SQE Test Inhibit bit (bit 18.2) in the 10Base-T Operations Register is logic one.
[This bit provides the Station Management entity (STA) with the ability to disable the SQE Test
function.]
Note:
1. In 10Base-T mode, a bit time has a typical duration of 100 ns.
2. The SQE Test also has the name 10Base-T Heartbeat. For details on the SQE waveforms, see Section
10.5.17, “10Base-T: Heartbeat Timing (SQE)”.
ICS1893AG, Rev. A 04/14/05
Copyright © 2005, Integrated Circuit Systems, Inc.
All rights reserved.
49
April, 2005
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