ICS1893BY-10 - Release
Chapter 6 Functional Blocks
6.5.8 10Base-T Operation: Collision Detection
The ICS1893BY-10 has a 10Base-T Collision Detection Function that establishes the state of its Collision
Detection signal (COL) based upon both (1) the state of its Receiver state machine and (2) the state of its
Transmit state machine. When the ICS1893BY-10 is operating in:
• Half-duplex mode, the ICS1893BY-10 asserts its COL signal to indicate it is receiving data while
transmission of data is also in progress.
• Full-duplex mode, the ICS1893BY-10 always sets its COL signal to FALSE.
6.5.9 10Base-T Operation: Jabber
The ICS1893BY-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 ICS1893BY-10 asserts its Collision Detect (COL)
signal. During this ISO/IEC specified ‘jabber de-activation time’, the ICS1893BY-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 ICS1893BY-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 ICS1893BY-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 ICS1893BY-10 has an ISO/IEC compliant Signal Quality Error (SQE) Test Function used exclusively
for 10Base-T operations. When enabled, the ICS1893BY-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 ICS1893BY-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 ICS1893BY-10 SQE Test Function is:
• Enabled only when all the following conditions are true:
– The ICS1893BY-10 is in node mode.
– The ICS1893BY-10 is in half-duplex mode.
– The ICS1893BY-10 has a valid link.
– The 10Base-T Operations Register’s SQE Test Inhibit bit (bit 18.2) is logic zero (the default).
– The ICS1893BY-10 TX_EN signal has transitioned from asserted (high) to de-asserted (low).
• Disabled whenever any of the following are true:
– The ICS1893BY-10 is in Repeater mode.
– The ICS1893BY-10 is in full-duplex mode.
– The ICS1893BY-10 detects a link failure.
ICS1893BY-10 Rev A 3/24/04
March, 2004
Copyright © 2004, Integrated Circuit Systems, Inc.
All rights reserved.
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ICSI [ INTEGRATED CIRCUIT SOLUTION INC ]
