ICST ICS1892Y, ICS1892Y-10, ICS1892Y-14 Datasheet

Integrated Circuit Systems, Inc.

Document Type: Data Sheet

ICS1892

Document Stage: Released

10Base-T/100Base-TX Integrated PHYceiver

General

The ICS1892, an enhanced version of the ICS 1890, is a fully integrated, physical-layer device (PHY) that is compliant with both the 10Base-T and 100Base-TX CSMA/CD Ethernet Standard, ISO/IEC 8802-3.

The ICS1892 incorporates digital signal processing (DSP) in its Physical Medium Dependent (PMD) sublayer. As a result, it can transmit and receive data on unshielded twisted-pair (UTP) category 5 cable with attenuation in excess of 24 dB at 100 MHz. With this ICS-patented technology, the ICS1892 can virtually eliminate errors from killer packets.

The ICS1892 supports a broad range of applications: data terminal equipment (network interface cards and motherboards), switches, repeaters, bridges, and routers. Its Media Independent Interface (MII) supports direct chip-to-chip and motherboard-to-daughterboard connections as well as connections to an MII connector and cable. The ICS1892 also provides a Serial Management Interface for exchanging command and status information with a Station Management (STA) entity.

The ICS1892 Media Dependent Interface (MDI) can be configured to provide either halfor full-duplex operation at data rates of 10 MHz or 100 MHz. The MDI configuration can be done manually (with input pins or control register settings) or automatically (using the Auto-Negotiation features). When the ICS1892 Auto-Negotiation sublayer is enabled, it exchanges technology capability data with its remote link partner and automatically selects the highest-performance operating mode they have in common.

ICS1892 Block Diagram

Features

•Supports category 5 cables with attenuation in excess of 24 dB at 100 MHz across a temperature range from -5° to +85° C

•DSP-based baseline wander correction to virtually

eliminate killer packets across temperature range of from -5° to +85° C

•Low-power, 0.5-micron CMOS

•Single 5.0-V power supply.

•Single-chip, fully integrated PHY provides PCS, PMA, PMD, and AUTONEG sublayers of IEEE standard

•10Base-T and 100Base-TX IEEE 802.3 compliant

•Fully integrated, DSP-based PMD includes:

–Adaptive equalization and baseline wander correction

–Transmit wave shaping and stream cipher scrambler

–MLT-3 encoder and NRZ/NRZI encoder

•Highly configurable design supports:

–Node, repeater, and switch applications

–Managed and unmanaged applications

–10M or 100M halfand full-duplex modes

–Parallel detection

–Auto-negotiation, with Next Page capabilities

•MAC/Repeater Interface can be configured as:

–10M or 100M Media Independent Interface

–100M Symbol Interface (bypasses the PCS)

–10M 7-wire Serial Interface

•Provides Loopback Modes for Diagnostic Functions

•Small Footprint 64-pin Low-Profile LQFP and MQFP packages available

100Base-T

10/100 MII or

PCS

PMA

TP_PMD

Interface

•

Frame

•

Clock Recovery

•

MLT-3

Integrated

Twisted-

Alternate

•

CRS/COL

•

Link Monitor

•

Stream Cipher

MUX

Detection

•

Signal Detection

•

Adaptive Equalizer

Switch

Pair

MAC/Repeater

•

Parallel to Serial

•

Error Detection

•

Baseline Wander

Interface to

Interface

•

4B/5B

Correction

Magnetics

10Base-T

Modules and

RJ45

Connector

MII

Low-Jitter

Configuration

Auto-

MII Serial

Extended

Clock

Register

and Status

Negotiation

Management

Synthesizer

Set

Interface

Clock

Power

LEDs and PHY

Address

1892 Rev. D, 2/26/01

ICS reserves the right to make changes in the device data identified in

this publication without further notice. ICS advises its customers to

obtain the latest version of all device data to verify that any information

being relied upon by the customer is current and accurate.

		ICS1892 Data Sheet	Table of Contents

Table of Contents

Section	Title	Page
Chapter 1 Abbreviations and Acronyms................................................................		9
Chapter 2 Conventions and Nomenclature..........................................................		11
Chapter 3 ICS 1892 Enhanced Features..............................................................		13
Chapter 4 Overview of the ICS 1892 ....................................................................		15
4.1	100Base-TX Operation ..............................................................................	16
4.2	10Base-T Operation ..................................................................................	16
Chapter 5 Operating Modes Overview ................................................................		17
5.1	Reset Operations .......................................................................................	18
5.1.1	General Reset Operations .........................................................................	18
5.1.2	Specific Reset Operations .........................................................................	19
5.2	Power-Down Operations ...........................................................................	20
5.3	Automatic Power-Saving Operations .........................................................	21
5.4	Auto-Negotiation Operations .....................................................................	21
5.5	100Base-TX Operations ............................................................................	22
5.6	10Base-T Operations ................................................................................	22
5.7	Half-Duplex and Full-Duplex Operations ...................................................	22
Chapter 6	Interface Overviews .............................................................................	23
6.1	MII Data Interface ......................................................................................	24
6.2	100M Symbol Interface ..............................................................................	25
6.3	10M Serial Interface ..................................................................................	27
6.4	Link Pulse Interface ...................................................................................	29
6.5	Serial Management Interface ....................................................................	30
6.6	Twisted-Pair Interface ................................................................................	30
6.7	Clock Reference Interface .........................................................................	30
6.7.1	Clock Source: Oscillator or CMOS Driver ..................................................	30
6.7.2	Clock Source: Crystal ................................................................................	31
6.8	Configuration Interface ..............................................................................	32
6.9	Status Interface .........................................................................................	32
Chapter 7	Functional Blocks ................................................................................	33
7.1	Functional Block: Media Independent Interface ........................................	34
7.2	Functional Block: Auto-Negotiation ...........................................................	35
7.2.1	Auto-Negotiation General Process ............................................................	36
7.2.2	Auto-Negotiation: Parallel Detection ..........................................................	37
7.2.3	Auto-Negotiation: Remote Fault Signaling ................................................	37
7.2.4	Auto-Negotiation: Reset and Restart .........................................................	38
7.2.5	Auto-Negotiation: Progress Monitor ..........................................................	39

ICS1892, Rev. D, 2/26/01	© 2000-2001, Integrated Circuit Systems, Inc.		February 26, 2001
	All rights reserved.	2

		ICS1892	Table of Contents

Table of Contents

Section	Title	Page
7.3	Functional Block: 100Base-X PCS and PMA Sublayers ...........................	41
7.3.1	PCS Sublayer ............................................................................................	41
7.3.2	PMA Sublayer ............................................................................................	41
7.3.3	PCS/PMA Transmit Modules .....................................................................	42
7.3.4	PCS/PMA Receive Modules ......................................................................	43
7.3.5	PCS Control Signal Generation .................................................................	44
7.3.6	4B/5B Encoding/Decoding .........................................................................	45
7.4	Functional Block: 100Base-TX TP-PMD Operations .................................	46
7.4.1	100Base-TX Operation: Stream Cipher Scrambler/Descrambler ..............	46
7.4.2	100Base-TX Operation: MLT-3 Encoder/Decoder ....................................	46
7.4.3	100Base-TX Operation: DC Restoration ...................................................	46
7.4.4	100Base-TX Operation: Adaptive Equalizer ..............................................	47
7.4.5	100Base-TX Operation: Twisted-Pair Transmitter .....................................	47
7.4.6	100Base-TX Operation: Twisted-Pair Receiver .........................................	47
7.4.7	100Base-TX Operation: Auto Polarity Correction ......................................	48
7.4.8	100Base-TX Operation: Isolation Transformer ..........................................	48
7.5	Functional Block: 10Base-T Operations ....................................................	49
7.5.1	10Base-T Operation: Manchester Encoder/Decoder ................................	49
7.5.2	10Base-T Operation: Clock Synthesis .......................................................	49
7.5.3	10Base-T Operation: Clock Recovery .......................................................	49
7.5.4	10Base-T Operation: Idle ..........................................................................	50
7.5.5	10Base-T Operation: Link Monitor .............................................................	50
7.5.6	10Base-T Operation: Smart Squelch .........................................................	51
7.5.7	10Base-T Operation: Carrier Detection .....................................................	51
7.5.8	10Base-T Operation: Collision Detection ..................................................	51
7.5.9	10Base-T Operation: Jabber .....................................................................	52
7.5.10	10Base-T Operation: SQE Test .................................................................	52
7.5.11	10Base-T Operation: Twisted-Pair Transmitter .........................................	53
7.5.12	10Base-T Operation: Twisted-Pair Receiver .............................................	53
7.5.13	10Base-T Operation: Auto Polarity Correction ..........................................	54
7.5.14	10Base-T Operation: Isolation Transformer ..............................................	54
7.6	Functional Block: Management Interface ..................................................	55
7.6.1	Management Register Set Summary ........................................................	55
7.6.2	Management Frame Structure ...................................................................	55

ICS1892, Rev. D, 2/26/01	© 2000-2001, Integrated Circuit Systems, Inc.		February 26, 2001
	All rights reserved.	3

		ICS1892 Data Sheet	Table of Contents

Table of Contents

Section	Title	Page
Chapter 8	Management Register Set...................................................................	58
8.1	Introduction to Management Register Set .................................................	59
8.1.1	Management Register Set Outline ............................................................	59
8.1.2	Management Register Bit Access .............................................................	60
8.1.3	Management Register Bit Default Values ..................................................	60
8.1.4	Management Register Bit Special Functions .............................................	61
8.2	Register 0: Control Register ......................................................................	62
8.2.1	Reset (bit 0.15) ..........................................................................................	62
8.2.2	Loopback Enable (bit 0.14) ........................................................................	63
8.2.3	Data Rate Select (bit 0.13) ........................................................................	63
8.2.4	Auto-Negotiation Enable (bit 0.12) ............................................................	63
8.2.5	Low Power Mode (bit 0.11) ........................................................................	64
8.2.6	Isolate (bit 0.10) .........................................................................................	64
8.2.7	Restart Auto-Negotiation (bit 0.9) ..............................................................	64
8.2.8	Duplex Mode (bit 0.8) ................................................................................	65
8.2.9	Collision Test (bit 0.7) ................................................................................	65
8.2.10	IEEE Reserved Bits (bits 0.6:0) .................................................................	65
8.3	Register 1: Status Register ........................................................................	66
8.3.1	100Base-T4 (bit 1.15) ................................................................................	66
8.3.2	100Base-TX Full Duplex (bit 1.14) ............................................................	67
8.3.3	100Base-TX Half Duplex (bit 1.13) ............................................................	67
8.3.4	10Base-T Full Duplex (bit 1.12) .................................................................	67
8.3.5	10Base-T Half Duplex (bit 1.11) ................................................................	67
8.3.6	IEEE Reserved Bits (bits 1.10:7) ...............................................................	68
8.3.7	MF Preamble Suppression (bit 1.6) ...........................................................	68
8.3.8	Auto-Negotiation Complete (bit 1.5) ..........................................................	68
8.3.9	Remote Fault (bit 1.4) ................................................................................	69
8.3.10	Auto-Negotiation Ability (bit 1.3) ................................................................	69
8.3.11	Link Status (bit 1.2) ....................................................................................	69
8.3.12	Jabber Detect (bit 1.1) ...............................................................................	70
8.3.13	Extended Capability (bit 1.0) .....................................................................	70
8.4	Register 2: PHY Identifier Register ............................................................	71

ICS1892, Rev. D, 2/26/01	© 2000-2001, Integrated Circuit Systems, Inc.		February 26, 2001
	All rights reserved.	4

		ICS1892	Table of Contents

Table of Contents

Section	Title	Page
8.5	Register 3: PHY Identifier Register ............................................................	73
8.5.1	OUI bits 19-24 (bits 3.15:10) .....................................................................	73
8.5.2	Manufacturer's Model Number (bits 3.9:4) ................................................	73
8.5.3	Revision Number (bits 3.3:0) .....................................................................	74
8.6	Register 4: Auto-Negotiation Register .......................................................	75
8.6.1	Next Page (bit 4.15) ...................................................................................	75
8.6.2	IEEE Reserved Bit (bit 4.14) ......................................................................	76
8.6.3	Remote Fault (bit 4.13) ..............................................................................	76
8.6.4	Technology Ability Field (bits 4.12:5) .........................................................	76
8.6.5	Selector Field (Bits 4.4:0) ..........................................................................	77
8.7	Register 5: Auto-Negotiation Link Partner Ability Register ........................	78
8.7.1	Next Page (bit 5.15) ...................................................................................	78
8.7.2	Acknowledge (bit 5.14) ..............................................................................	79
8.7.3	Remote Fault (bit 5.13) ..............................................................................	79
8.7.4	Technology Ability Field (bits 5.12:5) .........................................................	79
8.7.5	Selector Field (bits 5.4:0) ...........................................................................	79
8.8	Register 6: Auto-Negotiation Expansion Register .....................................	80
8.8.1	IEEE Reserved Bits (bits 6.15:5) ...............................................................	80
8.8.2	Parallel Detection Fault (bit 6.4) ................................................................	81
8.8.3	Link Partner Next Page Able (bit 6.3) ........................................................	81
8.8.4	Next Page Able (bit 6.2) ............................................................................	81
8.8.5	Page Received (bit 6.1) .............................................................................	81
8.8.6	Link Partner Auto-Negotiation Able (bit 6.0) ..............................................	81
8.9	Register 7: Auto-Negotiation Next Page Transmit Register ......................	82
8.9.1	Next Page (bit 7.15) ...................................................................................	83
8.9.2	IEEE Reserved Bit (bit 7.14) ......................................................................	83
8.9.3	Message Page (bit 7.13) ...........................................................................	83
8.9.4	Acknowledge 2 (bit 7.12) ...........................................................................	83
8.9.5	Toggle (bit 7.11) ........................................................................................	83
8.9.6	Message Code Field / Unformatted Code Field (bits 7.10:0) ....................	83
8.10	Register 8: Auto-Negotiation Next Page Link Partner Ability Register ......	84
8.10.1	Next Page (bit 8.15) ...................................................................................	85
8.10.2	IEEE Reserved Bit (bit 8.14) ......................................................................	85
8.10.3	Message Page (bit 8.13) ...........................................................................	85
8.10.4	Acknowledge 2 (bit 8.12) ...........................................................................	85
8.10.5	Message Code Field / Unformatted Code Field (bits 8.10:0) ....................	85

ICS1892, Rev. D, 2/26/01	© 2000-2001, Integrated Circuit Systems, Inc.		February 26, 2001
	All rights reserved.	5

		ICS1892 Data Sheet	Table of Contents

Table of Contents

Section	Title	Page
8.11	Register 16: Extended Control Register ....................................................	86
8.11.1	Command Override Write Enable (bit 16.15) ............................................	87
8.11.2	ICS Reserved (bits 16.14:11) ....................................................................	87
8.11.3	PHY Address (bits 16.10:6) .......................................................................	87
8.11.4	Stream Cipher Scrambler Test Mode (bit 16.5) .........................................	87
8.11.5	ICS Reserved (bit 16.4) .............................................................................	87
8.11.6	NRZ/NRZI Encoding (bit 16.3) ...................................................................	87
8.11.7	Invalid Error Code Test (bit 16.2) ..............................................................	88
8.11.8	ICS Reserved (bit 16.1) .............................................................................	88
8.11.9	Stream Cipher Disable (bit 16.0) ...............................................................	88
8.12	Register 17: Quick Poll Detailed Status Register ......................................	89
8.12.1	Data Rate (bit 17.15) .................................................................................	90
8.12.2	Duplex (bit 17.14) ......................................................................................	90
8.12.3	Auto-Negotiation Progress Monitor (bits 17.13:11) ...................................	91
8.12.4	100Base Receive Signal Lost (bit 17.10) ..................................................	91
8.12.5	PLL Lock Error (bit 17.9) ...........................................................................	92
8.12.6	False Carrier (bit 17.8) ...............................................................................	92
8.12.7	Invalid Symbol (bit 17.7) ............................................................................	92
8.12.8	Halt Symbol (bit 17.6) ................................................................................	93
8.12.9	Premature End (bit 17.5) ...........................................................................	93
8.12.10	Auto-Negotiation Complete (bit 17.4) ........................................................	93
8.12.11	100Base-TX Signal Detect (bit 17.3) .........................................................	93
8.12.12	Jabber Detect (bit 17.2) .............................................................................	93
8.12.13	Remote Fault (bit 17.1) ..............................................................................	94
8.12.14	Link Status (bit 17.0) ..................................................................................	94
8.13	Register 18: 10Base-T Operations Register ..............................................	95
8.13.1	ICS Reserved (bit 18.15) ...........................................................................	95
8.13.2	Polarity Reversed (bit 18.14) .....................................................................	96
8.13.3	ICS Reserved (bits 18.13:6) ......................................................................	96
8.13.4	Jabber Inhibit (bit 18.5) ..............................................................................	96
8.13.5	ICS Reserved (bit 18.4) .............................................................................	96
8.13.6	Auto Polarity Inhibit (bit 18.3) ....................................................................	96
8.13.7	SQE Test Inhibit (bit 18.2) .........................................................................	96
8.13.8	Link Loss Inhibit (bit 18.1) ..........................................................................	97
8.13.9	Squelch Inhibit (bit 18.0) ............................................................................	97

ICS1892, Rev. D, 2/26/01	© 2000-2001, Integrated Circuit Systems, Inc.		February 26, 2001
	All rights reserved.	6

		ICS1892	Table of Contents

Table of Contents

Section	Title	Page
8.14	Register 19: Extended Control Register 2 .................................................	98
8.14.1	Node/Repeater Configuration (bit 19.15) ...................................................	99
8.14.2	Hardware/Software Priority Status (bit 19.14) ...........................................	99
8.14.3	Remote Fault (bit 19.13) ............................................................................	99
8.14.4	ICS Reserved (bits 19.12:2) ......................................................................	99
8.14.5	Automatic 10Base-T Power-Down (bit 19.1) ...........................................	100
8.14.6	Automatic 100Base-TX Power-Down (bit 19.0) .......................................	100
Chapter 9	ICS 1892 Pin Listing and Pin Descriptions .....................................	101
9.1	ICS 1892 Pin Listings ..............................................................................	101
9.1.1	Pin Listing by Pin Number .......................................................................	102
9.1.2	Pin Listings by Alphabetical Pin Name ....................................................	103
9.2	ICS 1892 Pin Descriptions .......................................................................	104
9.2.1	Transformer Interface Pins ......................................................................	104
9.2.2	Multifunction (Multiplexed) Pins: PHY Address and LED Pins ................	105
9.2.3	Configuration Pins ...................................................................................	106
9.2.4	MAC/Repeater Interface Pins ..................................................................	109
9.2.5	Reserved Pins .........................................................................................	118
9.2.6	Ground and Power Pins ..........................................................................	118
Chapter 10	DC and AC Operating Conditions ..................................................	120
10.1	Absolute Maximum Ratings .....................................................................	120
10.2	Recommended Operating Conditions .....................................................	120
10.3	Recommended Component Values .........................................................	121
10.4	DC Operating Characteristics ..................................................................	122
10.4.1	DC Operating Characteristics for Supply Current ....................................	122
10.4.2	DC Operating Characteristics for TTL Inputs and Outputs ......................	122
10.4.3	DC Operating Characteristics for REF_IN ...............................................	122
10.4.4	DC Operating Characteristics for Media Independent Interface ..............	123
10.5	Timing Diagrams .....................................................................................	124
10.5.1	Timing for Clock Reference In (REF_IN) Pin ...........................................	124
10.5.2	Timing for Transmit Clock (TXCLK) Pin ..................................................	125
10.5.3	Timing for Receive Clock (RXCLK) Pin ...................................................	126
10.5.4	100M MII / 100M Stream Interface: Synchronous Transmit Timing ........	127
10.5.5	10M MII: Synchronous Transmit Timing ..................................................	128
10.5.6	MII / 100M Stream Interface: Synchronous Receive Timing ...................	129
10.5.7	MII Management Interface Timing ...........................................................	130
10.5.8	10M Serial Interface: Receive Latency ....................................................	131
10.5.9	10M Media Independent Interface: Receive Latency ..............................	132
10.5.10	10M Serial Interface: Transmit Latency ...................................................	133
10.5.11	10M Media Independent Interface: Transmit Latency .............................	134
10.5.12	MII / 100M Stream Interface: Transmit Latency ......................................	135
10.5.13	MII: Carrier Assertion/De-Assertion (Half-Duplex Transmission) ............	136

ICS1892, Rev. D, 2/26/01	© 2000-2001, Integrated Circuit Systems, Inc.		February 26, 2001
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		ICS1892 Data Sheet	Table of Contents

Table of Contents

Section	Title	Page
10.5.14	100M MII / 100M Stream Interface: Receive Latency .............................	137
10.5.15	Media Dependent Interface: Input-to-Carrier Assertion/De-Assertion .....	138
10.5.16	Reset: Power-On Reset ...........................................................................	139
10.5.17	Reset: Hardware Reset and Power-Down ...............................................	140
10.5.18	10Base-T: Heartbeat Timing (SQE) ........................................................	141
10.5.19	10Base-T: Jabber Timing ........................................................................	142
10.5.20	10Base-T: Normal Link Pulse Timing ......................................................	143
10.5.21	Auto-Negotiation Fast Link Pulse Timing ................................................	144
Chapter 11 Physical Dimensions of ICS 1892 Package...................................		145
Chapter 12	Ordering Information .......................................................................	147

ICS1892, Rev. D, 2/26/01	© 2000-2001, Integrated Circuit Systems, Inc.		February 26, 2001
	All rights reserved.	8

		ICS1892	Chapter 1 Abbreviations and Acronyms

Chapter 1 Abbreviations and Acronyms

Table 1-1 lists and interprets the abbreviations and acronyms used throughout this data sheet.

Table 1-1. Abbreviations and Acronyms

	Abbreviation /	Interpretation
	Acronym
	4B/5B	4-Bit / 5-Bit Encoding/Decoding
	ANSI	American National Standards Institute
	CMOS	complimentary metal-oxide semiconductor
	CSMA/CD	Carrier Sense Multiple Access with Collision Detection
	CW	Command Override Write
	DSP	digital signal processing
	ESD	End-of-Stream Delimiter
	FDDI	Fiber Distributed Data Interface
	FLP	Fast Link Pulse
	IDL	A ‘dead’ time on the link following a 10Base-T packet, not to be confused with idle
	IEC	International Electrotechnical Commission
	IEEE	Institute of Electrical and Electronic Engineers
	ISO	International Standards Organization
	LH	Latching High
	LL	Latching Low
	LMX	Latching Maximum
	MAC	Media Access Control
	Max.	maximum
	Mbps	Megabits per second
	MDI	Media Dependent Interface
	MF	Management Frame
	MII	Media Independent Interface
	Min.	minimum
	MLT-3	Multi-Level Transition Encoding (3 Levels)
	N/A	Not Applicable
	NLP	Normal Link Pulse
	No.	Number
	NRZ	Not Return to Zero
	NRZI	Not Return to Zero, Invert on one
	OSI	Open Systems Interconnection

ICS1892, Rev. D, 2/26/01	© 2000-2001, Integrated Circuit Systems, Inc.		February 26, 2001
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			ICS1892 Data Sheet			Chapter 1 Abbreviations and Acronyms
		Table 1-1. Abbreviations and Acronyms (Continued)
		Abbreviation /			Interpretation
			Acronym
		OUI		Organizationally Unique Identifier
		PCS		Physical Coding sublayer
		PHY		physical-layer device
				The ICS1892 is a physical-layer device, also referred to as a ‘PHY’ or ‘PHYceiver’. (The
				ICS 1890 is also a physical-layer device.)
		PLL		phase-locked loop
		PMA		Physical Medium Attachment
		PMD		Physical Medium Dependent
		ppm		parts per million
		QFP		quad flat pack
		RO		read only
		R/W		read/write
		R/W0		read/write zero
		SC		self-clearing
		SF		Special Functions
		SFD		Start-of-Frame Delimiter
		SI		Stream Interface
				Serial Interface
				Symbol Interface
				With reference to the MII/SI pin, the acronym ‘SI’ has multiple meanings.
				•	Generically, SI means 'Stream Interface', and is documented as such in the ICS
				•	1890 data sheet.
					However, when the MAC/Repeater Interface is configured for:
					– 10M operations, SI is an acronym for 'Serial Interface'.
					– 100M operations, SI is an acronym for 'Symbol Interface'.
		SQE		Signal Quality Error
		SSD		Start-of-Stream Delimiter
		STA		Station Management Entity
		STP		shielded twisted pair
		TAF		Technology Ability Field
		TP-PMD		Twisted-Pair Physical Layer Medium Dependent
		Typ.		typical
		UTP		unshielded twisted pair

ICS1892, Rev. D, 2/26/01	© 2000-2001, Integrated Circuit Systems, Inc.		February 26, 2001
	All rights reserved.	10

		ICS1892	Chapter 2 Conventions and Nomenclature

Chapter 2 Conventions and Nomenclature

Table 2-1 lists and explains the conventions and nomenclature used throughout this data sheet.

Table 2-1. Conventions and Nomenclature

Item		Convention / Nomenclature
Asterisk (*)	Within this table, see the item ‘Pin (or signal) names’
Bits	•	A bit in a register is identified using the format ‘register.bit’. For example, bit
	•	0.15 is bit 15 of register 0.
		When a colon is used with bits, it indicates the range of bits. For example,
	•	bits 1.15:11 are bits 15, 14, 13, 12, and 11 of register 1.
		For a range of bits, the order is always from the most-significant bit to the
		least-significant bit.
Code groups	Within this table, see the item ‘Symbols’
Colon (:)	Within this table, see these items:
	•	‘Bits’
	•	‘Pin (or signal) names’
Numbers	•	As a default, all numbers use the decimal system (that is, base 10) unless
		followed by a lowercase letter. A string of numbers followed by a lowercase
		letter:
		– A ‘b’ represents a binary (base 2) number
		– An ‘h’ represents a hexadecimal (base 16) number
	•	– An ‘o’ represents an octal (base 8) number
		All numerical references to registers use decimal notation (and not
		hexadecimal).
Pin (or signal) names	•	All pin or signal names are provided in capital letters.
	•	A pin name that includes a forward slash ‘/’ is a multi-function, configuration
		pin. These pins provide the ability to select between two ICS1892
		functions. The name provided:
		– Before the ‘/’ indicates the pin name and function when the signal level
		on the pin is logic zero.
		– After the ‘/’ indicates the pin name and function when the signal level on
		the pin is logic one.
		For example, the HW/SW pin selects between Hardware (HW) mode and
		Software (SW) mode.
		– When the signal level on the HW/SW pin is logic zero, the ICS1892
		Hardware mode is selected.
		– When the signal level on the HW/SW pin is logic one, the ICS1892
	•	Software mode is selected.
		An asterisk appended to the end of a pin name or signal name (such as
	•	RESET*) indicates an active-low operation.
		When a colon is used with pin or signal names, it indicates a range. For
	•	example, TXD[3:0] represents pins/signals TXD3, TXD2, TXD1, and TXD0.
		When pin name abbreviations are spelled out, words in parentheses
		indicate additional description that is not part of the pin name abbreviation.

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			ICS1892 Data Sheet		Chapter 2 Conventions and Nomenclature
		Table 2-1. Conventions and Nomenclature (Continued)
			Item		Convention / Nomenclature
		Registers		•	A bit in a register is identified using the format ‘register.bit’. For example, bit
				•	0.15 is bit 15 of register 0.
					All numerical references to registers use decimal notation (and not
				•	hexadecimal).
					When register name abbreviations are spelled out, words in parentheses
					indicate additional description that is not part of the register name
					abbreviation.
		Signal references		•	When referring to signals, the terms:
					– ‘FALSE’, ‘low’, or ‘zero’ represent signals that are logic zero.
				•	– ‘TRUE’, ‘high’, or ‘one’ represent signals that are logic one.
					Chapter 10, “DC and AC Operating Conditions” defines the electrical
					specifications for ‘logic zero’ and ‘logic one’ signals.
		Symbols		•	In this data sheet, code group names are referred to as ‘symbols’ and they
					are shown between '/' (slashes). For example, the symbol /J/ represents
				•	the first half of the Start-of-Stream Delimiter (SSD1).
					Symbol sequences are shown in succession. For example, /I/J/K/
					represents an IDLE followed by the SSD.
		Terms:		The terms ‘set’, ‘active’, and ‘asserted’ are synonymous.
		‘set’,		They do not necessarily infer logic one.
		‘active’,		(For example, an active-low signal can be set to logic zero.)
		‘asserted’,
		Terms:		The terms ‘cleared’, ‘inactive’, and ‘de-asserted’ are synonymous.
		‘cleared’,		They do not necessarily infer logic zero.
		‘de-asserted’,
		‘inactive’
		Terms:		In reference to the ICS1892, the term ‘Twisted-Pair Receiver’ refers to the set
		‘twisted-pair receiver’		of Twisted-Pair Receive output pins (TP_RXP and TP_RXN).
		Terms:		In reference to the ICS1892, the term ‘Twisted-Pair Transmitter’ refers to the
		‘twisted-pair transmitter’		set of Twisted-Pair Transmit output pins (TP_TXP and TP_TXN).

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		ICS1892	Chapter 3 ICS1892 Enhanced Features

Chapter 3 ICS1892 Enhanced Features

The ICS1892 is an enhanced version of the ICS 1890. In contrast to the ICS 1890, the ICS1892 offers significant improvements in both performance and features while maintaining backward compatibility. The specific differences between these devices are listed below.

1.The ICS1892 employs an advanced digital signal processing (DSP) architecture that improves the 100Base-TX Receiver performance beyond that of any other PHY in the market. Specifically:

a.The ICS1892 DSP-based, adaptive equalization process allows the ICS1892 to accommodate a maximum cable attenuation/insertion loss of 29 dB, which is nearly equivalent to the attenuation loss of a 150-meter Category 5 cable.

b.The ICS1892 DSP-based, baseline-wander correction process virtually eliminates killer packets.

2.The analog 10Base-T Receive Phase-Locked Loop (PLL) of the ICS 1890 is replaced with a digital PLL in the ICS1892, thereby resulting in lower jitter and improved stability.

3.The ICS 1890 Frequency-Locked Loop (FLL) that is part of the 100Base-TX Clock and Data Recovery circuitry is replaced with a digital FLL in the ICS1892, also resulting in lower jitter and improved stability.

4.The ICS1892 transmit circuits are improved in contrast to the ICS 1890, resulting in a decrease in the magnitude of the 10Base-T harmonic content generated during transmission. (See ISO/IEC 8802-3: 1993 clause 8.3.1.3.)

5.The ICS1892 supports the Auto-Negotiation Next Page functions described in IEEE Std 802.3u-1995 clause 28.2.3.4.

6.The ICS1892 supports Management Frame (MF) Preamble Suppression.

7.The ICS1892 provides the Remote Jabber capability.

8.The ICS1892 has an improved version of the ICS 1890 10Base-T Squelch operation.

9.The ICS1892 “seeds” (that is, initializes) the Transmit Stream Cipher Shift register by using the ICS1892 PHY address from Table 8-16, which minimizes crosstalk and noise in repeater applications.

10.The ICS1892 offers an automatic 10Base-T power-down mode.

11.The enhanced features of the ICS1892 required some modifications to the ICS 1890 Management Registers. However, the ICS1892 Management Registers are backward-compatible with the ICS 1890 Management Registers. Table 3-1 summarizes the differences between the ICS 1890 and the ICS1892 Management Registers.

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			ICS1892 Data Sheet			Chapter 3 ICS1892 Enhanced Features
		Table 3-1. Summary of Differences between ICS 1890 and ICS1892 Registers
		Register.		ICS 1890		ICS1892
			Bit(s)
				Function	Default	Function	Default
		1.6		Reserved	0b (always)	Management Frame Preamble	0b
						Suppression
		3.9:4		Model Number	000010b	Model Number	000011b
		3:0		Revision Number	0011b	Revision Number	0000b
		6.2		Next Page Able	0b (always)	Next Page Able	1b
		7.15:0		Not applicable (N/A)	N/A	Auto-Negotiate Next Page	2001h
						Transmit Register
		8.15:0		N/A	N/A	Auto-Negotiate Next Page	0000h
						Link Partner Ability
		9.15:0		IEEE reserved.	0000h	IEEE reserved.	FFFFh
			through			Note: Although the default value is
		15.15:0				changed, this response more
						accurately reflects an MDIO
						access to registers 9–15.
		18.15		Reserved	0b	Remote Jabber	0b
		19.1		Reserved	0b	Automatic 10Base-T Power Down	1b
		20.15:0		N/A	N/A	ICS test registers.	See specific
			through			(There is no claim of backward	registers and
		31.15:0				compatibility for these registers.)	bits.

Note:

1.There are new registers and bits. For example:

a.Registers 7 and 8 are new (that is, the ICS 1890 does not have these registers).

b.Registers 20 through 31 are new ICS test registers.

2.For some bits (such as the model number and revision number bits), the default values are changed.

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		ICS1892	Chapter 4 Overview of the ICS1892

Chapter 4 Overview of the ICS1892

The ICS1892 is a stream processor. During data transmission, it accepts sequential nibbles from its MAC (Media Access Control)/Repeater Interface, converts them into a serial bit stream, encodes them, and transmits them over the medium through an external isolation transformer. When receiving data, the ICS1892 converts and decodes a serial bit stream (acquired from an isolation transformer that interfaces with the medium) into sequential nibbles. It subsequently presents these nibbles to its MAC/Repeater Interface.

The ICS1892 implements the OSI model’s physical layer, consisting of the following, as defined by the ISO/IEC 8802-3 standard:

•Physical Coding sublayer (PCS)

•Physical Medium Attachment sublayer (PMA)

•Physical Medium Dependent sublayer (PMD)

•Auto-Negotiation sublayer

The ICS1892 is transparent to the next layer of the OSI model, the link layer. The link layer has two sublayers: the Logical Link Control sublayer and the MAC sublayer. The ICS1892 can interface directly to a MAC and offers multiple, configurable modes of operation. Alternately, this configurable interface can be connected to a repeater, which extends the physical layer of the OSI model.

The ICS1892 transmits framed packets acquired from its MAC/Repeater Interface and receives encapsulated packets from another PHY, which it translates and presents to its MAC/Repeater Interface.

Note: As per the ISO/IEC standard, the ICS1892 does not affect, nor is it affected by, the underlying structure of the MAC/repeater frame it is conveying.

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		ICS1892 Data Sheet	Chapter 4 Overview of the ICS1892

4.1100Base-TX Operation

During 100Base-TX data transmission, the ICS1892 accepts packets from a MAC/repeater and inserts Start-of-Stream Delimiters (SSDs) and End-of-Stream Delimiters (ESDs) into the data stream. The ICS1892 encapsulates each MAC/repeater frame, including the preamble, with an SSD and an ESD. As per the ISO/IEC Standard, the ICS1892 replaces the first octet of each MAC preamble with an SSD and appends an ESD to the end of each MAC/repeater frame.

When receiving data from the medium, the ICS1892 removes each SSD and replaces it with the pre-defined preamble pattern before presenting the nibbles to its MAC/Repeater Interface. When the ICS1892 encounters an ESD in the data stream, signifying the end of the frame, it ends the presentation of nibbles to its MAC/Repeater Interface. Therefore, the local MAC/repeater receives an unaltered copy of the transmitted frame sent by the remote MAC/repeater.

During periods when MAC frames are being neither transmitted nor received, the ICS1892 signals and detects the IDLE condition on the Link Segment. In the 100Base-TX mode, the ICS1892 transmit channel sends a continuous stream of scrambled ones to signify the IDLE condition. Similarly, the ICS1892 receive channel continually monitors its data stream and looks for a pattern of scrambled ones. The results of this signaling and monitoring provide the ICS1892 with the means to establish the integrity of the Link Segment between itself and its remote link partner and informing its Station Management Entity (STA) of the link status.

For 100M data transmission, the ICS1892 MAC/Repeater Interface can be configured to provide either a 100M Media Independent Interface (MII) or a 100M Symbol Interface. With the Symbol Interface configuration, the data stream bypasses the ICS1892 Physical Coding sublayer (PCS) and the following results:

1.The ICS1892 shifts the responsibility of performing the 4B/5B translation to the MAC/repeater. As a result, the requirement is for a 5-bit data path between the MAC/repeater and the ICS1892.

2.The latency through the ICS1892 reduces. (The ICS1892 provides this 100M Symbol Interface primarily for repeater applications for which latency is a critical performance parameter.)

4.210Base-T Operation

During 10Base-T data transmission, the ICS1892 inserts only the IDL delimiter into the data stream. The ICS1892 appends the IDL delimiter to the end of each MAC frame. It is not required to insert an SSD-like delimiter because the 10Base-T preamble already has a Start-of-Frame delimiter (SFD).

When receiving data from the medium (such as a twisted-pair cable), the ICS1892 uses the preamble to synchronize its receive clock. When the ICS1892 receive clock establishes lock, it presents the preamble nibbles to its MAC/Repeater Interface. The 10M MAC/Repeater Interface can be configured as either a 10M MII, a 10M Serial Interface, or a Link Pulse Interface.

In 10M operations, during periods when MAC frames are being neither transmitted nor received, the ICS1892 signals and detects Normal Link Pulses. This action allows the integrity of the Link Segment with the remote link partner to be established and then reported to the ICS1892’s STA.

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		ICS1892	Chapter 5 Operating Modes Overview

Chapter 5 Operating Modes Overview

The ICS1892 operating modes and interfaces are configurable with one of two methods. The first configuration method is by using hardware pins. With this method, the HW/SW (hardware/software) pin determines whether it is the hardware pins or the register bits that have priority for configuring the ICS1892.

The second – and more typical – configuration method is by using register bits, typically controlled from software. The register bits are accessible through a standard MII (Media Independent Interface) Serial Management Port. Even when the MAC/Repeater Interface is not supporting the standard MII Data Interface, access to the Serial Management Port is provided (that is, operation of the Serial Management Port is independent of the MAC/Repeater Interface configuration).

The ICS1892 provides a number of configuration functions to support a variety of operations. For example, the MAC/Repeater Interface can be configured to operate as a 10M MII, a 100M MII, a 100M Symbol Interface, a 10M Serial Interface, or a Link Pulse Interface. The protocol on the Medium Dependent Interface (MDI) can be configured to support either 10M or 100M operations in either half-duplex or full-duplex modes.

The ICS1892 is fully compliant with the ISO/IEC 8802-3 standard, as it pertains to both 10Base-T and 100Base-TX operations. The feature-rich ICS1892 allows easy migration from 10-Mbps to 100-Mbps operations as well as from systems that require support of both 10M and 100M links.

This chapter is an overview of the following ICS1892 modes of operation:

•Section 5.1, “Reset Operations”

•Section 5.2, “Power-Down Operations”

•Section 5.3, “Automatic Power-Saving Operations”

•Section 5.4, “Auto-Negotiation Operations”

•Section 5.5, “100Base-TX Operations”

•Section 5.6, “10Base-T Operations”

•Section 5.7, “Half-Duplex and Full-Duplex Operations”

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		ICS1892 Data Sheet	Chapter 5 Operating Modes Overview

5.1Reset Operations

This section first discusses reset operations in general and then specific ways in which the ICS1892 can be configured for various reset options.

5.1.1General Reset Operations

The following reset operations apply to all the specific ways in which the ICS1892 can be reset, which are discussed in Section 5.1.2, “Specific Reset Operations”.

5.1.1.1Entering Reset

When the ICS1892 enters a reset condition (either through hardware, power-on reset, or software), it does the following:

1.Isolates the MAC/Repeater Interface input pins

2.Drives all MAC/Repeater Interface output pins low

3.Tri-states the signals on its Twisted-Pair Transmit pins (TP_TXP and TP_TXN)

4.Initializes all its internal modules and state machines to their default states

5.Enters the power-down state

6.Initializes all internal latching low (LL), latching high (LH), and latching maximum (LMX) Management Register bits to their default values

5.1.1.2Exiting Reset

When the ICS1892 exits a reset condition, it does the following:

1.Exits the power-down state

2.Latches the Serial Management Port Address of the ICS1892 into the Extended Control Register, bits 16.10:6. [See Section 8.11.3, “PHY Address (bits 16.10:6)”.]

3.Enables all its internal modules and state machines

4.Sets all Management Register bits to either (1) their default values or (2) the values specified by their associated ICS1892 input pins, as determined by the HW/SW pin

5.Enables the Twisted-Pair Transmit pins (TP_TXP and TP_TXN)

6.Resynchronizes both its Transmit and Receive Phase-Locked Loops, which provide its transmit clock (TXCLK) and receive clock (RXCLK)

7.Releases all MAC/Repeater Interface pins, which takes a maximum of 640 ns after the reset condition is removed

5.1.1.3Hot Insertion

As with the ICS 1890, the ICS1892 reset design supports ‘hot insertion’ of its MII. (That is, the ICS1892 can connect its MAC/Repeater Interface to a MAC/repeater while power is already applied to the MAC/repeater.)

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		ICS1892	Chapter 5 Operating Modes Overview

5.1.2Specific Reset Operations

This section discusses the following specific ways that the ICS1892 can be reset:

•Hardware reset (using the RESET* pin)

•Power-on reset (applying power to the ICS1892)

•Software reset (using Control Register bit 0.15)

Note: At the completion of a reset (either hardware, power-on, or software), the ICS1892 sets all registers to their default values.

5.1.2.1Hardware Reset

Entering Hardware Reset

Holding the active-low RESET* pin low for a minimum of five REF_IN clock cycles initiates a hardware reset (that is, the ICS1892 enters the reset state). During reset, the ICS1892 executes the steps listed in Section 5.1.1.1, “Entering Reset”.

Exiting Hardware Reset

After the signal on the RESET* pin transitions from a low to a high state, the ICS1892 completes in 640 ns (that is, in 16 REF_IN clocks) steps 1 through 5, listed in Section 5.1.1.2, “Exiting Reset”. After the first five steps are completed, the Serial Management Port is ready for normal operations, but this action does not signify the end of the reset cycle. The reset cycle completes when the transmit clock (TXCLK) and receive clock (RXCLK) are available, which is typically 53 ms after the RESET* pin goes high. [For details on this transition, see Section 10.5.17, “Reset: Hardware Reset and Power-Down”.]

Note:

1.The MAC/Repeater Interface is not available for use until the TXCLK and RXCLK are valid.

2.The Control Register bit 0.15 does not represent the status of a hardware reset. It is a self-clearing bit that is used to initiate a software reset.

5.1.2.2Power-On Reset

Entering Power-On Reset

When power is applied to the ICS1892, it waits until the potential between VDD and VSS achieves a minimum voltage of 4.5 VDC before entering reset and executing the steps listed in Section 5.1.1.1, “Entering Reset”. After entering reset from a power-on condition, the ICS1892 remains in reset for approximately 20 s. (For details on this transition, see Section 10.5.16, “Reset: Power-On Reset”.)

Exiting Power-On Reset

The ICS1892 automatically exits reset and performs the same steps as for a hardware reset. (See Section 5.1.1.2, “Exiting Reset”.)

Note: The only difference between a hardware reset and a power-on reset is that during a power-on reset, the ICS1892 isolates the RESET* input pin. All other functionality is the same. As with a hardware reset, the Control Register bit 0.15 does not represent the status of a power-on reset.

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		ICS1892 Data Sheet	Chapter 5 Operating Modes Overview

5.1.2.3Software Reset

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 ICS1892 enters the reset state for two REF_IN clock cycles.

Note: 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 ICS1892 does not enter the power-down state.

Exiting Software Reset

At the completion of a reset (either hardware, power-on, or software), the ICS1892 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 RESET* 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 upon exiting a software-initiated reset, the ICS1892 does not re-latch its Serial Management Port Address into the Extended Control Register. [For information on the Serial Management Port Address, see Section 8.11.3, “PHY Address (bits 16.10:6)”.]

3.The Control Register bit 0.15 does not represent the status of a hardware reset. It is a self-clearing bit 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.

5.2Power-Down Operations

The ICS1892 enters the power-down state whenever either (1) the RESET* pin is low or (2) Control Register bit 0.11 (the Power-Down bit) is logic one. In the power-down state, the ICS1892 disables all internal functions and drives all MAC/Repeater Interface output pins to logic zero except for those that support the MII Serial Management Port. In addition, the ICS1892 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 ICS1892 enters the power-down state:

•By setting Control Register bit 0.11, the ICS1892 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 ICS1892 sets all of its Management Register bits to their default values. It does not maintain the state of any Management Register bit.

For more information on power-down operations, see the following:

•Section 8.14, “Register 19: Extended Control Register 2”

•Section 10.4, “DC Operating Characteristics”, which has tables that specify the ICS1892 power consumption while in the power-down state

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		ICS1892	Chapter 5 Operating Modes Overview

5.3Automatic Power-Saving Operations

The ICS1892 has power-saving features that automatically minimize its total power consumption while it is operating. Table 5-1 lists the ICS1892 automatic power-saving features for the various modes.

Table 5-1. Automatic Power-Saving Features, 10Base-T and 100Base-TX Modes

Power-		Mode for ICS1892
Saving
		10Base-T Mode		100Base-TX Mode
Feature
Disable Inter-	In 10Base-T mode, the ICS1892 disables		In 100Base-TX mode, the ICS1892
nal Modules	all its internal 100Base-TX modules.		disables all its internal 10Base-T modules.
STA Control	When an STA sets the state of the ICS1892		When an STA sets the state of the ICS1892
of Automatic	Extended Control Register 2, bit 19.0 to		Extended Control Register 2, bit 19.1 to
Power-	logic:		logic:
Saving	•	Zero, the 100Base-TX modules always	•	Zero, the 10Base-T modules always
Features		remain enabled, even during 10Base-T		remain enabled, even during
	•	operations.	•	100Base-TX operations.
		One, the ICS1892 automatically		One, the ICS1892 automatically
		disables 100Base-TX modules while the		disables 10Base-T modules while the
		ICS1892 is operating in 10Base-T		ICS1892 is operating in 100Base-TX
		mode.		mode.

5.4Auto-Negotiation Operations

The ICS1892 has an Auto-Negotiation sublayer. It provides both an input pin, ANSEL (Auto-Negotiation Select) and a Control Register bit (bit 0.12) to determine whether its Auto-Negotiation sublayer is enabled or disabled. The ICS1892 HW/SW input pin exclusively selects whether the ANSEL pin (which is used for the hardware mode) or Control Register bit 0.12 (which is used for the software mode) controls its Auto-Negotiation sublayer.

When enabled, the ICS1892 Auto-Negotiation sublayer exchanges technology capability data with its remote link partner and automatically selects the highest-performance operating mode it has in common with its remote link partner. For example, if the ICS1892 supports 100Base-TX and 10Base-T modes – but its link partner supports 100Base-TX and 100Base-T4 modes – the two devices automatically select 100Base-TX as the highest-performance common operating mode. For details regarding initialization and control of the auto-negotiation process, see Section 7.2, “Functional Block: Auto-Negotiation”.

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		ICS1892 Data Sheet	Chapter 5 Operating Modes Overview

5.5100Base-TX Operations

The ICS1892 100Base-TX mode is a primary operating mode that provides 100Base-TX physical layer (PHY) services as defined in the ISO/IEC 8802-3 standard. In the 100Base-TX mode, the ICS1892 is a 100M translator between a MAC/repeater and the physical transmission medium. As such, the ICS1892 has two interfaces, both of which are fully configurable: one to the MAC/repeater and one to the Link Segment. In 100Base-TX mode, the ICS1892 provides the following functions:

•Data conversion from both parallel-to-serial and serial-to-parallel formats

•Data encoding/decoding (4B/5B, NRZ/NRZI, and MLT-3)

•Data scrambling/descrambling

•Data transmission/reception over a twisted-pair medium

To accurately transmit and receive data, the ICS1892 employs DSP-based wave shaping, adaptive equalization, and baseline wander correction. In addition, in 100Base-TX mode, the ICS1892 provides a variety of control and status means to assist with Link Segment management. For more information on 100Base-TX, see Section 7.4, “Functional Block: 100Base-TX TP-PMD Operations”.

5.610Base-T Operations

The ICS1892 10Base-T mode is another primary operating mode that provides 10Base-T physical layer (PHY) services as defined in the ISO/IEC 8802-3 standard. In the 10Base-T mode, the ICS1892 is a 10M translator between a MAC/repeater and the physical transmission medium. As such, the ICS1892 has two interfaces, both of which are fully configurable: one to the MAC/repeater and one to the Link Segment. In 10Base-T mode, the ICS1892 provides the following functions:

•Data conversion from both parallel-to-serial and serial-to-parallel formats

•Manchester data encoding/decoding

•Data transmission/reception over a twisted-pair medium

In addition, in 10Base-T mode, the ICS1892 provides a variety of control and status means to assist with Link Segment management. For more information on 10Base-T, see Section 7.5, “Functional Block: 10Base-T Operations”.

5.7Half-Duplex and Full-Duplex Operations

The ICS1892 supports half-duplex and full-duplex operations for both 10Base-T and 100Base-TX applications. Full-duplex operation allows simultaneous transmission and reception of data, which effectively doubles the Link Segment throughput to either 20 Mbps (for 10Base-T operations) or 200 Mbps (for 100Base-TX operations).

As per the ISO/IEC standard, full-duplex operations differ slightly from half-duplex operations. These differences are necessary, as during full-duplex operations a PHY actively uses both its transmit and receive data paths simultaneously.

•In 10Base-T full-duplex operations, the ICS1892 disables its loopback function (that is, it does not automatically loop back data from its transmitter to its receiver and disable its SQE Test function).

•In both 10Base-T and 100Base-TX full-duplex operations, the ICS1892 asserts its CRS signal only in response to receive activity while its COL signal always remains inactive.

For more information on half-duplex and full-duplex operations, see the following sections:

•Section 8.2, “Register 0: Control Register”

•Section 8.2.8, “Duplex Mode (bit 0.8)”

•Section 8.3, “Register 1: Status Register”

•Section 8.6, “Register 4: Auto-Negotiation Register”

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		ICS1892	Chapter 6 Interface Overviews

Chapter 6 Interface Overviews

The ICS1892 MAC/Repeater Interface is fully configurable, thereby allowing it to accommodate many different applications.

This chapter includes overviews of the following MAC/repeater-to-PHY interfaces:

•Section 6.1, “MII Data Interface”

•Section 6.2, “100M Symbol Interface”

•Section 6.3, “10M Serial Interface”

•Section 6.4, “Link Pulse Interface”

•Section 6.5, “Serial Management Interface”

•Section 6.6, “Twisted-Pair Interface”

•Section 6.7, “Clock Reference Interface”

•Section 6.8, “Configuration Interface”

•Section 6.9, “Status Interface”

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		ICS1892 Data Sheet	Chapter 6 Interface Overviews

6.1MII Data Interface

The most common configuration for the ICS1892 MAC/Repeater Interface is to configure the MAC/Repeater Interface as a Medium Independent Interface (MII) operating at either 10 Mbps or 100 Mbps (depending on the configuration). When the MAC/Repeater Interface is configured for the MII Data Interface mode, the MAC/Repeater Interface is used to transfer between the ICS1892 and the MAC/repeater framed, 4-bit parallel nibbles, along with control and status signals.

The ICS1892 implements an MII that is fully compliant with the IEEE Std 802.3u when connecting to MACs or repeaters. The ICS1892 MII supports a variety of interfaces to MACs and repeaters, which can occur as follows:

•On the same board (that is chip to chip)

•On a motherboard to a daughterboard

•Through an MII connector and cable (in a manner similar to AUI connections)

Clause 22 of the ISO/IEC standard defines the MII between an Ethernet PHY and the MAC/Reconciliation sublayer for 10-Mbps and 100-Mbps operations. The specification supports a variety of physical media, including 100Base-TX, 100Base-T4, and 100Base-FX. The specification is such that use of a specific medium for the Link Segment is transparent to the MAC. The ICS1892 supports this definition for both 100Base-TX and 10Base-T operations.

The ISO/IEC-specified MII has both a transmit and a receive data path. Each data path can synchronously exchange 4 bits of data (that is, nibbles).

•The transmit data path includes the following:

–A data nibble, TXD[3:0]

–A transmit data clock to synchronize transfers, TXCLK

–A transmit enable signal, TXEN

–A transmit error signal, TXER

•The receive data path includes the following:

–A separate data nibble, RXD[3:0]

–A receive data clock to synchronize transfers, RXCLK

–A receive data valid signal, RXDV

–A receive error signal, RXER

Both the transmit clock and the receive clock are provided to the MAC/Reconciliation sublayer by the ICS1892 (that is, the ICS1892 sources the TXCLK and RXCLK signals).

Clause 22 also defines as part of the MII a Carrier Sense signal (CRS) and a Collision Detect signal (COL). The ICS1892 is fully compliant with these definitions and sources both of these signals to the MAC/repeater. When operating in:

•Half-duplex mode, the ICS1892 asserts the Carrier Sense signal when data is being either transmitted or received. While operating in half-duplex mode, the ICS1892 also asserts the Collision Detect signal to indicate that data is being received while a transmission is in progress.

•Full-duplex mode, the ICS1892 asserts the Carrier Sense signal only when receiving data and forces the Collision Detect signal to remain inactive.

As mentioned in Section 5.1.1.3, “Hot Insertion”, the ICS1892 design allows hot insertion of its MII. That is, it is possible to connect its MII to a MAC when power is already applied to the MAC. To support this functionality, the ICS1892 isolates its MII signals and tri-states the signals on the Twisted-Pair Transmit pins (TP_TXP and TP_TXN) during a power-on reset. Upon completion of the reset process, the ICS1892 enables its MII and enables its Twisted-Pair Transmit signals.

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6.2100M Symbol Interface

The 100M Symbol Interface has a primary objective of supporting 100Base-TX repeater applications for which the repeater requires only recovered parallel data and for which the repeater provides all the necessary framing and control functions.

When the Mac/Repeater Interface is configured for 100M Symbol operations, the ICS1892 and the MAC/repeater exchange unframed 5-bit, parallel symbols at a 25-MHz clock rate.

The ICS1892 configuration functions determine the operation of the MAC/Repeater Interface. The configuration functions are controlled by either input pins (in which case, the HW/SW pin is logic zero to select the hardware mode) or Management Register bits (in which case, the HW/SW pin is logic one to select the software mode).

•In hardware mode, the ICS1892 enables the 100M Symbol Interface when both of the following are true:

–The MII/SI input pin is logic one (that is, the selection is for the Symbol Interface).

–The 10/100SEL input pin is logic one (that is, the selection is for 100M operations).

•In software mode, the ICS1892 enables the 100M Symbol Interface when both the following are true:

–The MII/SI input pin is logic one (that is, the selection is for the Symbol Interface).

–The Control Register Data Rate bit (bit 0.13) is set to logic one (that is, the selection is for selecting 100M operations)

Note: In software mode, the 10/100SEL pin becomes an output that indicates the state of bit 0.13.

The 100M Symbol Interface bypasses the ICS1892 PCS and provides a direct unscrambled, unframed, 5-bit interface between the MAC/repeater and the PMA sublayer. A benefit of bypassing the PCS is a reduction in the latency through the ICS1892. That is, when the ICS1892 MAC/Repeater Interface is configured as a 100M Symbol Interface, the bit delays through the ICS1892 are smaller than the standard MII Data Interface can allow. The ICS1892 provides this 100M Symbol Interface primarily for Repeater applications, for which latency is a critical performance parameter.

In addition to the exchange of symbol data, the ICS1892 provides ISO/IEC-compliant control signals (such as CRS) to the MAC/repeater. The ICS1892 CRS signal provides a fast look-ahead, which can benefit a repeater application.

In the 100M Symbol Interface mode, the ICS1892 continues to assert the CRS signal using its PCS logic. This action does not affect the bit delay or latency because the PCS CRS logic examines the bits received from the PMA sublayer serially. In fact, because the PCS CRS does not wait for a nibble or symbol to be constructed, the PCS CRS is available in advance of the symbol generation. Therefore, by employing the PCS CRS generation logic, the ICS1892 can provide an ‘early’ indication of a Carrier Detect to the MAC/repeater.

The 100M Symbol Interface consists of the following fourteen signals: STCLK, STD[4:0], SRCLK, SRD[4:0], SCRS, and SD. (When the ICS1892 MAC/Repeater Interface is configured for 100M Symbol operations, its default MII pin names and their associated functions are redefined. For more information, see Section 9.2.4.2, “MAC/Repeater Interface Pins for 100M Symbol Interface”.)

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Table 6-1 lists the pin mappings for the ICS1892 100M Symbol Interface mode.

Table 6-1. Pin Mappings for 100M Symbol Interface Mode

Default	MAC/Repeater Interface Pin Mappings, Configured for
10M / 100M	100M Symbol Interface Mode
MII Pin Names
COL	No connect. [Because the MAC/repeater sources both active and ‘idle’ data, a PHY
	cannot distinguish between an active and idle transmission channel (that is, to a PHY
	the transmit channel always appears active). Therefore, a PHY cannot accurately
	detect a collision.]
CRS	SCRS
LSTA	SD
MDC	MDC
MDIO	MDIO
RXCLK	SRCLK
RXD0	SRD0
RXD1	SRD1
RXD2	SRD2
RXD3	SRD3
RXDV	No connect. (Data exchanged between the MAC/repeater and a PHY is not framed in
	the 100M Symbol Interface mode. Therefore, RXDV has no meaning.)
RXER	SRD4
TXCLK	STCLK
TXD0	STD0
TXD1	STD1
TXD2	STD2
TXD3	STD3
TXEN	No connect. (100Base-TX operations require continuous transmission of data.
	Therefore, the MAC/repeater is responsible for sourcing IDLE symbols when it is not
	transmitting data.)
TXER	STD4

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6.310M Serial Interface

When the Mac/Repeater Interface is configured as a 10M Serial Interface, the ICS1892 and the MAC/repeater exchange a framed, serial bit stream along with associated control signals. The 10M Serial Interface configuration is ideally suited to applications that already incorporate a serial 10Base-T MAC with a standard ‘7-wire’ interface. The ICS1892 MAC/Repeater Interface can be configured for 10M Serial Interface operations, as determined by ICS1892 configuration functions. When the HW/SW pin is set for:

•Hardware mode, the 10M Serial Interface is selected when the following are true:

–The MII/SI input pin is logic one (that is, the selection is for a Serial Interface).

–The 10/100SEL input pin is logic zero (that is, the selection is for 10M operations).

–The 10/LP input pin is logic zero

•Software mode, the 10M Serial Interface is selected when the following are true:

–The MII/SI input pin is logic one (that is, the selection is for a Serial Interface).

–The Control Register Data Rate bit (bit 0.13) is logic zero (that is, the selection is for 10M operations).

–The 10/LP input pin is logic zero

Note: In software mode, the 10/100SEL pin becomes an output that indicates the state of bit 0.13.

The 10M Serial Interface has two data paths: one for data transmission and one for data reception. Each data path exchanges a serial bit stream with the MAC/repeater at a 10-MHz clock rate. A benefit of using the 10M Serial Interface – in contrast to the 10M MII Interface – is a reduction in the bit latency through the ICS1892. This reduction is attributed to the elimination of both parallel-to-serial and serial-to-parallel data conversions.

The 10M Serial Interface consists of the following nine signals: 10TCLK, 10TXEN, 10TD, 10RCLK, 10RXDV, 10RD, 10CRS, 10COL, and LSTA. (When the ICS1892 MAC/Repeater Interface is configured for 10M Serial operations, both its default MII pin names and their associated functions are redefined. For more information, see Section 9.2.4.3, “MAC/Repeater Interface Pins for 10M Serial Interface”.)

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Table 6-2 lists the pin mappings for the ICS1892 10M Serial Interface mode.

Table 6-2. Pin Mappings for 10M Serial Interface Mode

Default	MAC/Repeater Interface Pin Mappings, Configured for
10M / 100M	10M Serial Interface Mode
MII Pin Names
COL	10COL
CRS	10CRS
LSTA	LSTA
MDC	MDC
MDIO	MDIO
RXCLK	10RCLK
RXD0	10RD
RXD1, RXD2, RXD3	No connect. [Data reception is serial, so only the 10RD (RXD0) pin is needed.]
RXDV	10RXDV
RXER	No connect. (10Base-T mode does not support error generation or detection.)
TXCLK	10TCLK
TXD0	10TD
TXD1, TXD2, TXD3	No connect. [Data transmission is serial, so only the 10TD (TXD0) pin is needed.]
TXEN	10TXEN
TXER	No connect. (0Base-T mode does not support error generation or detection.)

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6.4Link Pulse Interface

The Link Pulse Interface allows an application to control each step in the auto-negotiation process except for the actual generation and reception of 10Base-T link pulses (that is, Normal Link Pulses). The ICS1892 MAC/Repeater Interface can be configured as a Link Pulse Interface as determined by ICS1892 configuration functions.

The Link Pulse Interface is selected as follows:

•The HW/SW pin must be set for the hardware setting (logic low).

•The MII/SI input pin must be set for the Symbol/Serial Interface (logic high).

•The 10/LP input pin must be set for Link Pulse mode (logic high).

•The 10/100SEL input pin must be set for 100M operations (logic high).

Although the 10/100SEL pin must be set for 100M operations, a Normal Link Pulse has the same ISO/IEC definition regardless of whether the 10/100SEL pin is set for 10M (10 MHz) or 100M (100 MHz.)

The Link Pulse Interface allows the MAC/repeater to control the transmission of Normal Link Pulses to the remote link partner, thereby allowing the MAC/repeater to control the auto-negotiation processes.

The Link Pulse Interface consists of the following five signals: LTCLK, LPTX, LRCLK, LPRX, and SD. (When the ICS1892 MAC/Repeater Interface is configured for Link Pulse operations, its default MII pins are redefined. For more information, see Section 9.2.4.4, “MAC/Repeater Interface Pins for Link Pulse Interface”.)

Table 6-3 lists the ICS1892 pin mappings for the ICS1892 Link Pulse Interface mode.

Table 6-3. Pin Mappings for Link Pulse Interface Mode

Default	MAC/Repeater Interface Pin Mappings, Configured for
10M / 100M	Link Pulse Interface Mode
MII Pin Names
COL	No connect
CRS	No connect
LSTA	SD
MDC	MDC
MDIO	MDIO
RXCLK	LRCLK
RXD0, RXD1, RXD2, RXD3	No connect
RXDV	No connect
RXER	LPRX
TXCLK	LTCLK
TXD0, TXD1, TXD2, TXD3	No connect
TXEN	No connect
TXER	LPTX

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6.5Serial Management Interface

The ISO/IEC 8802-3 standard specifies a two-wire Serial Management Interface and protocol as part of the MII. This interface is used to exchange configuration, control, and status information between a Station Management entity (an STA) and a physical layer device (a PHY). The ISO/IEC standard specifies a frame structure and protocol for this interface as well as a set of Management Registers that it can access. The ICS1892 implementation of this interface complies fully with the ISO/IEC standard. It provides a bi-directional data pin (MDIO) along with an input pin for the clock (MDC). The clock is used to synchronize all data transfers between a PHY and the STA.

In addition to the ISO/IEC defined registers, the ICS1892 provides several extended status and control registers to provide more refined control of the MII and MDI interfaces. For example, the QuickPoll Detailed Status Register provides the ability to acquire the most-important status functions with a single MDIO read.

In the ICS1892, the MDIO and MDC pins remain active for all the MAC/Repeater Interface modes, that is, 10M/100M MII, 100M Symbol, 10M Serial, and Link Pulse. Therefore, to the ICS1892 the signals from these pins represent the Serial Management Interface, not just the MII Management Interface.

6.6Twisted-Pair Interface

The ICS1892 twisted-pair interface consists of the following:

•Twisted-Pair Transmitter: The differential Twisted-Pair Transmit pins TP_TXP and TP_TXN

•Twisted-Pair Receiver: The differential Twisted-Pair Receive pins TP_RXP and TP_RXN

•Transmit current-select pins: 10TCSR and 100TCSR

The ICS1892 uses the same pins for both 10Base-T and 100Base-TX operating modes. The differential Twisted-Pair Transmit and Twisted-Pair Receive pins directly interface with a universal magnetic module, which in turn interfaces with a single RJ-45 connector. The universal magnetic module has two isolation transformers: one for the transmit channel and one for the receive channel. The isolation transformers provide the interface between the ICS1892 and the twisted-pair medium.

6.7Clock Reference Interface

The REF_IN and REF_OUT pins provide the ICS1892 Clock Reference Interface. The ICS1892 requires a single clock reference with a frequency of 25 MHz ±50 parts per million. This accuracy is necessary to meet the interface requirements of the ISO/IEE 8802-3 standard, specifically clauses 22.2.2.1 and 24.2.3.4.

The ICS1892 supports three clock source configurations. The clock source can be from (1) an oscillator, (2) a CMOS driver, or (3) a crystal. The following paragraphs offer specific design recommendations for these clock sources.

6.7.1Clock Source: Oscillator or CMOS Driver

When using either an oscillator or a CMOS driver, the design must provide a connection from the clock source to the ICS1892 REF_IN pin while leaving the ICS1892 REF_OUT pin unconnected. ICS also recommends that the design provide a dedicated driver for the REF_IN pin.

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6.7.2Clock Source: Crystal

Figure 6-1 shows the recommended configuration when a crystal is used to supply the ICS1892 clock source. As shown, connect the two leads of the crystal between the ICS1892 pins REF_IN and REF_OUT. To properly load the crystal, also add two capacitors (C1 and C2 of Figure 6-1): one connected between REF_IN and ground (digital domain) and one connected between REF_OUT and ground (digital domain).

Note: Because a crystal is a tuned RLC circuit, crystal loading has a significant impact on the clock source accuracy.

As revealed by an impedance analysis of the recommended crystal configuration circuit, capacitors C1 and C2 are in series. In addition, the circuit has stray capacitance, which Figure 6-1 shows as CS3 and CS4. This stray capacitance is the collective result of board layout and pad capacitance.

Stray capacitance CS3 is in parallel with C1, depicted cumulatively as CL1. Stray capacitance CS4 is in parallel with C2, depicted cumulatively as CL2. Therefore, the total capacitive load as viewed by the crystal is the series sum of the two capacitors CL1 and CL2. (To add capacitors in series, add their inverse.)

If the capacitors C1 and C2 have the same value (which is recommended), then CL1 = CL2. In this case, each capacitance CL1 and CL2 equals twice the rated load capacitance of the crystal. For example, if CS3 = CS4 = 5 pF, and the rated capacitive load of the crystal is 25 pF, then C1 = C2 = 45 pF.

(CL1 = CL2 = 50 pF. Therefore, CL1 in parallel with CL2 equals 25 pF.)

Crystal accuracy is affected by load capacitance. The following factors also affect the crystal accuracy and must be considered when selecting a crystal for a design:

•The crystal cut. The crystal must be cut for accuracy. In some cases, this cut can require using a fixture that has equivalent capacitive loading characteristics as the final application.

•The crystal temperature characteristics

•The crystal aging characteristics

•CL1 and CL2, that is, the specific capacitive loading that occurs as a result of the particular printed circuit board that is used and the board layout

Figure 6-1. Recommended Configuration for a Crystal Clock Source

CS3	C1	C2	CS4
	CL1	CL2

REF_IN

ICS1892

REF_OUT

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6.8Configuration Interface

The Configuration and Status Interface pins (10/100SEL, 10/LP, ANSEL, DPXSEL, HW/SW, MII/SI, NOD/REP, RESET* and RXTRI) allow the ICS1892 to be completely configured and controlled in hardware. With these pins, the ICS1892 can accommodate the following:

•10M or 100M operations

•5 MAC/Repeater Interface configurations:

–10M MII

–100M MII

–100M Symbol

–10M Serial

–Link Pulse

•Node or repeater applications

•Full-duplex or half-duplex data links

In addition to the ISO/IEC-specified, MII control signals, the ICS1892 provides RXTRI, which is a tri-state enable pin for the MII receive data path. When this pin is active (that is, a logic one), the pins RXCLK, RXD[3:0], RXER, and RXDV are all tri-stated. Functionally, this pin affects the MII receive channel in the same way as the Control Register’s isolate bit, bit 0.10. (The isolate bit also affects the transmit data path.) The ICS1892 can tri-state these seven signals for all five types of MAC/Repeater Interface configurations, not just the MII interface.

6.9Status Interface

The ICS1892 LSTA pin provides a Link Status, and the LOCK pin provides a Stream Cipher Locking Status. In addition, as listed in Table 6-4, the ICS1892 provides the five multiplexed pins that monitor the data link by providing signals that drive LEDs. (Table 9.2.2 lists the pin numbers.)

Table 6-4. Pins for Monitoring the Data Link

Pin	LED Driven by the Pin’s Output Signal
P0AC	AC (Link Activity) LED
P1CL	CL (Collisions) LED
P2LI	LI (Link Integrity) LED
P3TD	TD (Transmit Data) LED
P4RD	RD (Receive Data) LED

The ICS1892 multiplexes each of these five LED output signals with one of the five PHY address inputs. The following example shows how this multiplexing takes place:

1.The PHY Address bit P0 and the link activity LED (AC) share pin 58. During a reset of the ICS1892, the signal on the link activity LED pin (as well as the other four LED pins) become inputs.

2.When the ICS1892 leaves the reset state, it latches the state of these inputs into the PHY Address bits (that is, the Serial Management Port Address) described in Table 8-16.

3.Next, the ICS1892 converts these pin signals to output signals that can drive an LED directly as follows: The state/value of each PHY Address bit is selected by connecting its associated LED signal to either VDD (to select a logic one) or VSS (to select a logic zero).

4.After the reset process completes, the ICS1892 uses the latched PHY address to drive the LED, independent of its connection to VDD or VSS.

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		ICS1892	Chapter 7 Functional Blocks

Chapter 7 Functional Blocks

This chapter discusses the following ICS1892 functional blocks.

•Section 7.1, “Functional Block: Media Independent Interface”

•Section 7.2, “Functional Block: Auto-Negotiation”

•Section 7.3, “Functional Block: 100Base-X PCS and PMA Sublayers”

•Section 7.4, “Functional Block: 100Base-TX TP-PMD Operations”

•Section 7.5, “Functional Block: 10Base-T Operations”

•Section 7.6, “Functional Block: Management Interface”

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7.1Functional Block: Media Independent Interface

All ICS1892 MII interface signals are fully compliant with the ISO/IEC 8802-3 standard. In addition, the ICS1892 MIIs can support two data transfer rates: 25 MHz (for 100Base-TX operations) and 2.5 MHz (for 10Base-T operations).

The Media Independent Interface (MII) consists of two primary components:

1.An interface between a MAC (Media Access Control sublayer) and the PHY (that is, the ICS1892). This MAC-PHY part of the MII consists of three subcomponents:

a.A synchronous Transmit interface that includes the following signals:

(1)A data nibble, TXD[3:0]

(2)An error indicator, TXER

(3)A delimiter, TXEN

(4)A clock, TXCLK

b.A synchronous Receive interface that includes the followings signals:

(1)A data nibble, RXD[3:0]

(2)An error indicator, RXER

(3)A delimiter, RXDV

(4)A clock, RXCLK

c.A Media Status or Control interface that consists of a Carrier Sense signal (CRS) and a Collision Detection signal (COL).

2.An interface between the PHY (the ICS1892) and an STA (Station Management entity). The STA-PHY part of the MII is a two-wire, Serial Management Interface that consists of the following:

a.A clock (MDC)

b.A synchronous, bi-directional data signal (MDIO) that provides an STA with access to the ICS1892 Management Register set

The ICS1892 Management Register set (discussed in Chapter 8, “Management Register Set”) consists of the following:

•Basic Management registers.

As defined in the ISO/IEC 8802-3 standard, these registers include the following:

–Control Register (register 0), which handles basic device configuration

–Status Register (register 1), which reports basic device capabilities and status

•Extended Management registers.

As defined in the ISO/IEC 8802-3 standard, the ICS1892 supports Extended registers that provide access to the Organizationally Unique Identifier and all auto-negotiation functionality.

•ICS (Vendor-Specific) Management registers.

The ICS1892 provides vendor-specific registers for enhanced PHY operations. Among these is the QuickPoll Detailed Status Register that provides a comprehensive and consolidated set of real-time PHY information. Reading the QuickPoll register enables the MAC to obtain comprehensive status data with a single register access.

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7.2Functional Block: Auto-Negotiation

The auto-negotiation logic of the ICS1892 has the following main functions:

•To determine the capabilities of the remote link partner, (that is, the device at the other end of the link segment’s medium or cable)

•To advertise the capabilities of the ICS1892 to the remote link partner

•To establish a protocol with the remote link partner using the highest-performance operating mode that they have in common

The design of the ICS1892 Auto-Negotiation sublayer supports both legacy 10Base-T connections as well as new connections that have multiple technology options for the link. For example, when the ICS1892 has the auto-negotiation process enabled and it is operating with a 10Base-T remote link partner, the ICS1892 monitors the link and automatically selects the 10Base-T operating mode – even though the remote link partner does not support auto-negotiation. This process, called parallel detection, is automatic and transparent to the remote link partner and allows the ICS1892 to function seamlessly with existing legacy network structures without any management intervention.

(For an overview of the auto-negotiation process, see Section 5.4, “Auto-Negotiation Operations”.)

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7.2.1Auto-Negotiation General Process

The Auto-Negotiation sublayer uses a physical signaling technique that is transparent at the packet level and all higher protocol levels. This technique builds on the link pulse mechanism employed in 10Base-T operations and is fully compliant with clause 28 of the ISO/IEC 8802-3 standard.

During the auto-negotiation process, both the ICS1892 and its remote link partner use Fast Link Pulses (FLPs) to simultaneously ‘advertise’ (that is, exchange) information on their respective technology capabilities as follows:

1.For the auto-negotiation process to take place, both the ICS1892 and its remote link partner must first both support and be enabled for Auto-Negotiation.

2.The ICS1892 obtains the data for its FLP bursts from the Auto-Negotiation Advertisement Register (Register 4).

3.Both the ICS1892 and the remote link partner substitute Fast Link Pulse (FLP) bursts in place of the Normal Link Pulses (NLPs). In each FLP burst, the ICS1892 transmits information on its technology capability through its Link Control Word, which includes link configuration and status data.

4.Similarly, the ICS1892 places the Auto-Negotiation data received from its remote link partner's FLP bursts into the Auto-Negotiation Link Partner Ability Register (Register 5).

5.After the ICS1892 and its remote link partner exchange technology capability information, the ICS1892 Auto-Negotiation sublayer contrasts the data in Registers 4 and 5 and automatically selects for the operating mode the highest-priority technology that both Register 4 and 5 have in common. (That is, both the ICS1892 and its remote link partner use a predetermined priority list for selecting the operating mode, thereby ensuring that both sides of the link make the same selection.) As follows from Annex 28B of the ISO/IEC 8802-3 standard, the pre-determined technology priorities are listed from 1 (highest priority) to 5 (lowest priority):

(1)100Base-TX full duplex

(2)100Base-T4. (The ICS1892 does not support this technology.)

(3)100Base-TX (half duplex)

(4)10Base-T full duplex

(5)10Base-T (half duplex)

Table 7-1 shows an example of how the selection process of the highest-priority technology takes place.

Table 7-1. Example of Selection Process of Highest-Priority Technology

If Register 4 Has These		If Register 5 Has These		Resulting Highest-Priority Common
Technologies:		Technologies:		Technology from Auto-Negotiation
				Sublayer
(3)	100Base-TX half duplex	(1)	100Base-TX full duplex	(3) 100Base-TX half duplex
(4)	10Base-T full duplex	(3)	100Base-TX half duplex

6.To indicate that the auto-negotiation process is complete, the ICS1892 sets bits 1.5 and 17.4 high to logic one. After successful completion of the auto-negotiation process, the ICS1892 Auto-Negotiation sublayer performs the following steps:

a.It sets to logic one the Status Register’s Auto-Negotiation Complete bit (bit 1.5, which is also available in the QuickPoll register as bit 17.4).

b.It enables the negotiated link technology (such as the 100Base Transmit modules and 100Base Receive modules).

c.It disables the unused technologies to reduce the overall power consumption.

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7.2.2Auto-Negotiation: Parallel Detection

The ICS1892 supports parallel detection. It is therefore compatible with networks that do not support the auto-negotiation process. When enabled, the Auto-Negotiation sublayer can detect legacy 10Base-T link partners as well as 100Base-TX link partners that do not have an auto-negotiation capability.

The Auto-Negotiation sublayer performs this parallel detection function when it does not get a response to its FLP bursts. In these situations, the Auto-Negotiation sublayer performs the following steps:

1.It sets the LP_AutoNeg_Able bit (bit 6.0) to logic zero, thereby identifying the remote link partner as not being capable of executing the auto-negotiation process.

2.It sets the bit in the Auto-Negotiation Link Partner Abilities Register that corresponds to the 'parallel detected' technology [for example, half-duplex, 10Base-T (bit 5.5) or half-duplex, 100Base-TX (bit 5.7)]. IEEE specification allows only half-duplex operation with auto-negotiation paralled detect partners.

3.It sets the Status Register’s Auto-Negotiation Complete bit (bit 1.5) to logic one, indicating completion of the auto-negotiation process.

4.It enables the detected link technology and disables the unused technologies.

A remote link partner that does not support the auto-negotiation process does not respond to the transmitted FLP bursts. The ICS1892 detects this situation and responds according to the data it receives. The ICS1892 can receive one of five potential responses to the FLP bursts it is transmitting: FLP bursts, 10Base-T link pulses (that is, Normal Link Pulses), scrambled 100Base IDLEs, nothing, or a combination of signal types.

A 10Base-T link partner transmits only Normal Link Pulses when idle. When the ICS1892 receives Normal Link Pulses, it concludes that the remote link partner is a device that can use only 10Base-T technology. A 100Base-TX node without an Auto-Negotiation sublayer transmits 100M scrambled IDLE symbols in response to the FLP bursts. Upon receipt of the scrambled IDLEs, the ICS1892 concludes that its remote link partner is a 100Base-TX node that does not support the auto-negotiation process. For both 10Base-T and 100Base-TX nodes without an Auto-Negotiation sublayer, the ICS1892 clears bit 6.0 to logic zero, indicating that the link partner cannot perform the auto-negotiation process.

If the remote link partner responds to the FLP bursts with FLP bursts, then the link partner is a 100Base-TX node that can support the auto-negotiation process. In this case, the ICS1892 sets to logic one the Auto-Negotiation Expansion Register’s Link Partner Auto-Negotiation Ability bit (bit 6.0).

If the Auto-Negotiation sublayer does not receive any signal when monitoring the receive channel, then the QuickPoll Detailed Status Register’s Signal Detect bit (bit 17.3) is set to logic one, indicating that no signal is present.

Another possibility is that the ICS1892 senses that it is receiving multiple technology indications. In this situation, the ICS1892 cannot determine which technology to enable. It informs the STA of this problem by setting to logic one the Auto-Negotiation Expansion Register’s Parallel Detection Fault bit (bit 6.4).

7.2.3Auto-Negotiation: Remote Fault Signaling

If the remote link partner detects a fault, the ICS1892 reports the remotely detected fault to the STA by setting to logic one the Remote Fault Detected bit(s), 1.4, 5.13, and 17.1. The reception of a remote link fault during the technology exchange also indicates that the remote link partner can perform remote fault detection and the Remote Fault bit (bit 19.13) is set to logic one. In general, the reception of a remote fault means that the remote link partner has a problem with the integrity of its receive channel.

Similarly, if the ICS1892 detects a link fault, it transmits a remote fault-detected condition to its remote link partner. In this situation, the ICS1892 sets to logic one the Auto-Negotiation Link Partner Ability Register’s Remote Fault Indication bit (bit 5.13). In addition, the ICS1892 sets to logic one the Extended Control Register’s bit 19.13, indicating that it sent a remote fault to its remote link partner.

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7.2.4Auto-Negotiation: Reset and Restart

If enabled, execution of the ICS1892 auto-negotiation process occurs at power-up and upon management request. There are two primary ways to begin the Auto-Negotiation state machine:

•ICS1892 reset

•Auto-Negotiation Restart

7.2.4.1Auto-Negotiation Reset

During a reset, the ICS1892 initializes its Auto-Negotiation sublayer modules to their default states. (That is, the Auto-Negotiation Arbitration State Machine and the Auto-Negotiation Progress Monitor reset to their idle states.) In addition, the Auto-Negotiation Progress Monitor status bits are all set to logic zero. This action occurs for any type of reset (hardware reset, software reset, or power-on reset).

7.2.4.2Auto-Negotiation Restart

As with a reset, during an Auto-Negotiation restart, the ICS1892 initializes the Auto-Negotiation Arbitration State Machine and the Auto-Negotiation Progress Monitor modules to their default states. However, during an Auto-Negotiation Restart, the Auto-Negotiation Progress Monitor status bits maintain their current state. Only three events can alter the state of the Auto-Negotiation Progress Monitor status bits after a Restart:

(1) an STA read operation, (2) a reset, or (3) the Auto-Negotiation Arbitration State Machine progressing to a higher state or value.

The Auto-Negotiation Progress Monitor Status bits change only if they are progressing to a state with a value greater than their current state (that is, a state with a higher logical value than that of their current state). For a detailed explanation of these bits and their operation, see Section 7.2.5, “Auto-Negotiation: Progress Monitor”.

After the Auto-Negotiation Arbitration State Machine reaches its final state (which is Auto-Negotiation Complete), only an STA read of the QuickPoll Detailed Status Register or an ICS1892 reset can alter these status bits.

Any one of the following situations initiate a restart of the ICS1892 Auto-Negotiation sublayer:

•A link failure

•In software mode (that is, HW/SW pin is logic one), either of the following actions initiate a restart of the ICS1892 Auto-Negotiation sublayer:

–Writing a logic one to the Control Register’s Restart Auto-Negotiation bit (bit 0.9), which is a selfclearing bit.

–Toggling the Control Register’s Auto-Negotiation Enable bit (bit 0.12) from a logic one to a logic zero, and back to a logic one.

•In hardware mode (that is, HW/SW pin is a logic zero), toggling the ANSEL (Auto-Negotiation Select) pin from a logic one to a logic zero, and back to a logic one.

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7.2.5Auto-Negotiation: Progress Monitor

Under typical circumstances, the Auto-Negotiation sublayer can establish a connection with the ICS1892’s remote link partner. However, some situations can prevent the auto-negotiation process from properly achieving this goal. For these situations, the ICS1892 has an Auto-Negotiation Progress Monitor to provide detailed status information to its Station Management (STA) entity. With this status information, the STA can diagnose the failure mechanism and – in some situations – establish the link by correcting the problem.

When enabled, the auto-negotiation process typically requires less than 500 ms to execute, independent of the link partner's ability to perform the auto-negotiation process. Typically, an STA polls both the Auto-Negotiation Complete bit (bit 1.5) and the Link Status bit (bit 1.2) to determine when a link is successfully established, either through auto-negotiation or parallel detection. The STA can then poll the Auto-Negotiation Link Partner Ability Register and determine the highest-performance operating mode in common with the capabilities it is advertising.

The ISO/IEC-defined priority table determines the established link type. As a simpler alternative, the STA can read the QuickPoll Detailed Status Register and determine the link type from the Data Rate bit (bit 17.15) and the Duplex bit (bit 17.14). For convenience, the QuickPoll Register also includes the Link Status bit (bit 17.0) and the Auto-Negotiation Complete bit (bit 17.4).

If (1) the auto-negotiation process does not complete, or (2) the link is not established, or (3) both the auto-negotiation process does not complete and the link is not established, then the STA can determine the cause of the link failure by using the outputs of the ICS1892 Auto-Negotiation Progress Monitor.

The Auto-Negotiation Progress Monitor provides the STA with four status bits of data to indicate both the history and the present state of the auto-negotiation process. This status data is provided in the QuickPoll Detailed Status register by using the Auto-Negotiation Complete bit (bit 17.4) as well as bits 17.13:11. The bit order, from most-significant bit to least-significant bit, is 17.4, 17.13, 17.12, and 17.11. Using these four bits, the Auto-Negotiation Progress Monitor provides nine state codes detailing the operation of the auto-negotiation process for the STA. [For more information, see Section 8.12.3, “Auto-Negotiation Progress Monitor (bits 17.13:11)”.]

The nine Auto-Negotiation Progress Monitor state codes are 0h through 8h and Fh. The Auto-Negotiation Progress Monitor automatically latches the values of the Auto-Negotiation Arbitration State Machine into the status bits only if the value of the present state is greater than the value that is currently in the status bits.

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For example, if the status bits have a value of 3h and the auto-negotiation process moves into:

•State 1, the Auto-Negotiation Progress Monitor does not update the status bits to indicate the new state.

•State 5, the Auto-Negotiation Progress Monitor updates the status bits to indicate the new state, State 5. In this case, the status bits increase in value until either the auto-negotiation process successfully completes or the STA reads the Auto-Negotiation Progress Monitor status bits.

When the STA reads the status bits, the present state of the auto-negotiation process is automatically latched into the status bits, regardless of how they compare to the value currently in the latch. However, the read presents the STA with the previously latched values of the status bits, not the values just latched into the status register by the read. Therefore, the STA must perform two reads of the status bits to determine the present state of the Auto-Negotiation Arbitration State Machine.

The first read provides a 'history' of the auto-negotiation process, (that is, the highest state achieved by the auto-negotiation process). The second read provides the present state of the auto-negotiation process. This behavior allows management to determine the greatest forward progress made by the auto-negotiation logic, which is valuable for diagnosing link errors and failures.

Note: Once the auto-negotiation process completes successfully, the value of all the Progress Monitor status bits and the Auto-Negotiation Complete bit have a value of logic one. A read operation of the QuickPoll Register provides a value of logic one for the Auto-Negotiation Complete bit and an octal value of 111 for the status bits.

However, subsequent reads of the QuickPoll Register also provide a value of logic one for the Auto-Negotiation Complete bit. The octal value of the status bits are ‘000’, providing the link remains established. That is, if the link fails, the Auto-Negotiation sublayer is restarted and subsequent reads provide the value of the Auto-Negotiation Arbitration State Machine.

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7.3Functional Block: 100Base-X PCS and PMA Sublayers

Clause 24 of the ISO/IEC specification defines the 100Base-X Physical Coding sublayer (PCS) and Physical Medium Attachment (PMA) sublayers. The ICS1892 is fully compliant with this clause in its implementation.

7.3.1PCS Sublayer

The ICS1892 100Base-X PCS sublayer provides two interfaces: one to a MAC/repeater and the other to the ICS1892 PMA sublayer. In addition, it performs the transmit, receive, and control functions in compliance with the ISO/IEC 8802-3 standard.

The ICS1892 100Base-X PCS PCS sublayer consists of the following:

•PCS Transmit sublayer, which provides the following:

–Parallel-to-serial conversion

–4B/5B encoding

–Collision detection

•PCS Receive sublayer, which provides the following:

–Serial-to-parallel conversion

–4B/5B encoding

–Carrier detection

–Code group framing

•Two PCS controls, which provide the following functions for the MAC/Repeater Interface:

–Assertion of the CRS carrier sense signal (which is part of the carrier sense modules)

–Assertion of the COL collision detection signal (which is part of the transmit modules)

Note: When configured for 100M Symbol mode operations, the MAC/Repeater Interface bypasses most of the PCS. When the ICS1892 MAC/Repeater Interface is in this mode, most of its PCS Transmit and Receive modules are inactive. However, its PCS control functions (CRS and COL) remain operational.

7.3.2PMA Sublayer

The ICS1892 100Base-X PMA Sublayer consists of two interfaces: one to the Physical Coding sublayer and the other to the Physical Medium Dependent sublayer. Functionally, the PMA sublayer is responsible for the following:

•Link Monitoring

•Carrier Detection

•NRZI encoding/decoding

•Transmit Clock Synthesis

•Receive Clock Recovery

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7.3.3PCS/PMA Transmit Modules

Both the PCS and PMA sublayers have Transmit modules.

7.3.3.1PCS Transmit Module

The ICS1892 PCS Transmit module accepts nibbles from the MAC/Repeater Interface and converts the nibbles into 5-bit ‘code groups’ (referred to here as ‘symbols’). Then the PCS Transmit module performs a parallel-to-serial conversion on the symbols, and subsequently passes the resulting serial bit stream to the PMA sublayer.

The first 16 nibbles of each MAC/Repeater Frame represent the Frame Preamble. The PCS replaces the first two nibbles of the Frame Preamble with the Start-of-Stream Delimiter (SSD), that is, the symbols /J/K/. After receipt of the last Frame nibble, detected when TX_EN = FALSE, the PCS appends to the end of the Frame an End-of-Stream Delimiter (ESD), that is, the symbols /T/R/. (The ICS1892 PCS does not alter any other data included within the Frame.)

The PCS Transmit module also performs collision detection. When the transmission and reception of data occur simultaneously, then in compliance with the ISO/IEC specification, when the ICS1892 is in:

•Half-duplex mode, the ICS1892 asserts the collision detection signal (COL).

•Full-duplex mode, COL is always FALSE.

7.3.3.2PMA Transmit Module

The ICS1892 PMA Transmit module accepts a serial bit stream from the PCS and converts it into NRZI format. Subsequently, the PMA passes the NRZI bit stream to the Twisted-Pair Physical Medium Dependent (TP-PMD) sublayer.

The ICS1892 PMA Transmit module uses a digital PLL to synthesize a transmit clock from the Clock Reference Interface. When the ICS1892 is configured for an interface that is:

•10M MII (that is, 10Base-T), the TXCLK signal is 2.5 MHz

•10M Serial Interface, the TXCLK signal is 10 MHz

•Either of the following, the TXCLK signal (a buffered version of the REF_IN signal) is 25 MHz:

–100M MII (that is, 100Base-TX)

–100M Symbol Interface

Note:

1.All of the TXCLK signals are derived from the REF_IN signal that goes to the digital PLL.

2.For the MII, for both the 10Base-T and 100Base-TX modes, the clock that is generated synchronizes all data transfers across the MII.

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7.3.4PCS/PMA Receive Modules

Both the PCS and PMA sublayers have Receive modules.

7.3.4.1PCS Receive Module

The ICS1892 PCS Receive module accepts both a serial bit stream and a clock signal from the PMA sublayer. The PCS Receive module converts the bit stream from a serial format to a parallel format and then processes the data to detect the presence of a carrier.

When a link is in the idle state, the PCS Receive module receives IDLE symbols. (All bits are logic one.) Upon receiving two non-contiguous zeros in the bit stream, the PCS Receive module examines the ensuing bits and attempts to locate the Start-of-Stream Delimiter (SSD), that is, the /J/K/ symbols.

Upon verification of a valid SSD, the PCS Receive module substitutes the first two standard nibbles of a Frame Preamble for the detected SSD. In addition, the PCS Receive module uses the SSD to begin framing the ensuing data into 5-bit code symbols. The final PCS Receive module performs 4B/5B decoding on the symbols and then synchronously passes the resulting nibbles to the MAC/Repeater Interface.

The Receive state machine continues to accept PMA data, convert it from serial to parallel format, frame it, decode it, and pass it to the MAC/Repeater Interface. During this time, the Receive state machine alternates between the Receive and Data States and continues this process until detection of one of the following:

•An End-of-Stream Delimiter (ESD, that is, the /T/R/ symbols)

•An error

•A premature end (IDLEs)

Upon receipt of an ESD, the Receive state machine returns to the IDLE state without passing the ESD to the MAC/Repeater Interface. Detection of an error forces the Receive state machine to assert the receive error signal (RX_ER) and wait for the next symbol. If the ICS1892 Receive state machine detects a premature end, it forces the assertion of the RX_ER signal, sets the Premature End bit (bit 17.5) to logic one, and transitions to the IDLE State.

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7.3.4.2PMA Receive Modules

The ICS1892 PMA Receive module provides the following two functions:

•NRZI Decoding

–The Receive module performs the NRZI decoding on the serial bit stream received from the Twisted-Pair Physical Medium Dependent (TP-PMD) sublayer. It converts the bit stream to a unipolar, positive, binary format which the PMA subsequently passes it to the PCS.

–The PMA extracts the clock embedded in the serial data stream.

•Receive Clock Recovery

The Receive Clock Recovery function consists of a phase-locked loop (PLL) that operates on the serial data stream received from the PMD sublayer. This PLL automatically synchronizes itself to the clock encoded in the serial data stream and then provides both a recovered clock and data stream to the PCS.

The Receive Clock PLL requires a clock reference to acquire lock. Without a clock source, it continually searches for a reference signal. Therefore, when the ICS1892 does not detect the presence of any signal on its receive channel, it uses a Transmit Clock function to generate a reference for the Receive Clock PLL. This is TBD.

The PMA Link Monitoring function observes the Receive Clock PLL. If the Receive Clock PLL cannot acquire ‘lock’ on the serial data stream, it asserts an error signal. The status of this error signal can be read in the QuickPoll Detailed Status Register’s PLL Lock Error bit (bit 17.9). 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”.)

In general, the ICS1892 PMA Link Monitor functions continually audit the state of the connection with the remote link partner. They assert a receive channel error if a receive signal is not detected or if a PLL Lock Error occurs. These errors, in turn, generate a link fault and force the link monitor functions to clear both the Status Register’s Link Status bit (bit 1.2) and the QuickPoll Detailed Status Register’s Link Status bit (bit 17.0).

7.3.5PCS Control Signal Generation

For the PCS sublayer, there are two control signals: a Carrier Sense signal (CRS) and a Collision Detect signal (COL).

The CRS control signals is generated as follows:

1.When a logic zero is detected in an idle bit stream, the Receive Functions examine the ensuing bits.

2.When the Receive Functions find the first two non-contiguous zero bits, the Receive state machine moves into the Carrier Detect state.

3.As a result, the Boolean Receiving variable is set to TRUE.

4.Consequently, the Carrier Sense state machine moves into the Carrier Sense ‘on’ state, which asserts the CRS signal.

5.If the PCS Functions:

a.Cannot confirm either the /I/J/ (IDLE, J) symbols or the /J/K/ symbols, the receive error signal (RX_ER) is asserted, and the Receive state machine returns to the IDLE state. In IDLE, the Boolean Receiving variable is set to FALSE, thereby causing the Carrier Sense state machine to set the CRS signal to FALSE.

b.Can confirm the /I/J/K/ symbols, then the Receive state machine transitions to the ‘Receive’ state.

The COL control signal is generated by the transmit modules. For details, see Section 7.3.3.1, “PCS Transmit Module”.

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7.3.64B/5B Encoding/Decoding

The 4B/5B coding methodology maps each 4-bit nibble to a 5-bit symbol (also called a “code group”). There are 32 five-bit symbols, which include the following:

•Of the 32 five-bit symbols, 16 five-bit symbols are required to represent the 4-bit nibbles.

•The remaining 16 five-bit symbols are available for control functions. The IEEE Standard defines 6 symbols for control, and the remaining 10 symbols of this grouping are invalid. The 6 control symbols include the following:

–/H/ represents a Transmit Error

–/I/ represents an IDLE

–Two symbols represent the Start-of-Stream Delimiter (SSD): /J/ and /K/

–Two symbols represent the End-of-Stream Delimiter (ESD): /T/ and /R/

If the ICS1892 PCS receives:

–One of the 10 undefined symbols, it sets the QuickPoll Detailed Status Register’s Invalid Symbol bit (bit 17.7) to logic one.

–A Halt symbol, it sets the Halt Symbol Detected bit in the QuickPoll Detailed Status Register (bit 17.6) to logic one.

Note: By an STA (1) setting the Extended Control Register’s Transmit Invalid Codes bit (bit 16.2) to logic one and (2) asserting the TXER signal, an STA can force the ICS1892 to transmit symbols that are typically classified as invalid. For more information, see Section 8.11.7, “Invalid Error Code Test (bit 16.2)”.

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