ICS1893Y-10 Datasheet, PDF (56/150 Pages) –

ICS1893Y-10 Data Sheet - Release
Chapter 6 Functional Blocks
6.5.9 10Base-T Operation: Jabber
The ICS1893Y-10 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 9.5.20,
“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 ICS1893Y-10 asserts its Collision Detect (COL)
signal. During this ISO/IEC specified ‘jabber de-activation time’, the ICS1893Y-10 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 ICS1893Y-10 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 7.1.4.1, “Latching High
Bits” and Section 7.1.4.2, “Latching Low Bits”.)
The ICS1893Y-10 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.
6.5.10 10Base-T Operation: SQE Test
The ICS1893Y-10 has an ISO/IEC compliant Signal Quality Error (SQE) Test Function used exclusively for
10Base-T operations. When enabled, the ICS1893Y-10 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
ICS1893Y-10 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 9.5.19, “10Base-T: Heartbeat Timing
(SQE)”.]
An ICS1893Y-10 SQE Test Function is:
• Enabled only when all the following conditions are true:
– The ICS1893Y-10 is in node mode.
– The ICS1893Y-10 is in half-duplex mode.
– The ICS1893Y-10 has a valid link.
– The 10Base-T Operations Register’s SQE Test Inhibit bit (bit 18.2) is logic zero (the default).
– The ICS1893Y-10 TX_EN signal has transitioned from asserted (high) to de-asserted (low).
• Disabled whenever any of the following are true:
– The ICS1893Y-10 is in Repeater mode.
– The ICS1893Y-10 is in full-duplex mode.
– The ICS1893Y-10 detects a link failure.
– The ICS1893Y-10 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
9.5.19, “10Base-T: Heartbeat Timing (SQE)”.
ICS1893Y-10 Rev F 1/20/04
Copyright © 2004, Integrated Circuit Systems, Inc.
All rights reserved.
56
January, 2004