IEEE
`Std 8D2_3u—1995
`
`SUPPLEMENT TO 802.3:
`
`Clock Pulses
`
`,\,\....
`
`|:II'31 Bit on Wire 1
`Dalajb 1
`Encoding —p D0
`Pulse
`Pulse
`Position Position
`1
`2
`
`1
`D1
`Pulse
`Pulse
`Pulse
`Position Position Position
`3
`4
`5
`
`o
`D2
`Pulse
`Pulse
`POSE ion Position
`6
`7
`
`Figure 28-4—Data bit encoding within FLP Bursts
`
`T3
`
`T1
`
`l*
`
`Clock Pulse
`
`Data Pulse
`
`Clock Pulse
`
`Figure 28-5—FLP Burst pulse-to-pulse timing
`
`The fi.1‘st link pulse in consecutive FLP Blusts shall occur at a 16 :: 8 ms intezival (figure 28-6).
`
`T5
`
`iii.
`
`FLP Bi-fit
`
`FLP Burst
`
`Figure 28-6—FLP Burst to FLP Burst timing
`
`Table 28-1—FLP Burst timing summary
`
`Parameter
`
`Clock-‘Data Pulse W'idth (figure 14-12)
`Clock Pulse to (‘lock Pulse
`
`Clock Pulse to Data Pulse (Data = 1)
`Pulses in a Burst
`
`Burst Width
`
`FLP Burst to FLP Burst
`
`This is armkrchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`Aerohive - Exhibit
`
`Aerohive - Exhibit 1025
`
`0261
`
`

`
`CSMA/CD
`
`28.2.1.2 Link Code Word encoding
`
`IEEE
`Std 802.3u-1995
`
`The base Link Code Word (base page) transmitted within an FLP Burst shall convey the encoding shown in
`figure 28-7. The Auto-Negotiation function may support additional pages using the Next Page fimction.
`Encodings for the Link Code Word(s) used in Next Page exchange are defined in 28.2.3.4. In an FLP Burst,
`D0 shall be the first bit transmitted.
`
`D0
`
`D1
`
`D2
`
`D3 D4 D5
`
`D6 D7
`
`D8
`
`D9 D10 D11 D12 D13 D14 D15
`
`Technology Ability Field
`Selector Field
`
`
`28.2.1.2.1 Selector Field
`
`Selector Field (S[4:0]) is a five bit wide field, encoding 32 possible messages. Selector Field encoding defi-
`nitions are shown in armex 28A. Combinations not specified are reserved for future use. Reserved combina-
`tions of the Selector Field shall not be transmitted.
`
`28.2.1 .2.2 Technology Ability Field
`
`Technology Ability Field (A[7:0]) is an eight bit wide field containing information indicating supported
`technologies specific to the selector field value. These bits are mapped to individual technologies such that
`abilities are advertised in parallel for a single selector field value. The Technology Ability Field encoding for
`the IEEE 802.3 selector is described in annex 28B.2. Multiple technologies may be advertised in the Link
`Code Word. A device shall support the data service ability for a technology it advertises. It is the responsibil-
`ity of the Arbitration function to determine the common mode of operation shared by a Link Partner and to
`resolve multiple common modes.
`
`NOTE—While devices using a Selector Field value other than the IEEE 802.3 Selector Field value are free to define the
`Technology Ability Field bits, it is recommended that the 10BASE-T bit be encoded hr the same bit position as in the
`IEEE 802.3 selector. A common bit position can be important if the technology using the other selector will ever coexist
`on a device that also offers a 10BASE-T mode.
`
`28.2.1.2.3 Remote Fault
`
`Remote Fault (RF) is encoded in bit D13 of the base Link Code Word. The default value is logic zero. The
`Remote Fault bit provides a standard transport mechanism for the transmission of simple fault information.
`When the RF bit in the Auto-Negotiation advertisement register (register 4) is set to logic one, the RF bit in
`the transmitted base Link Code Word is set to logic one. When the RF bit in the received base Link Code
`Word is set to logic one, the Remote Fault bit in the MII status register (register 1) will be set to logic one, if
`the MH management function is present.
`
`The Remote Fault bit shall be used in accordance with the Remote Fault function specifications (28.2.3.5).
`
`28.2.1 .2.4 Acknowledge
`
`Acknowledge (Ack) is used by the Auto-Negotiation fimction to indicate that a device has successfully
`received its Link Partner’s Link Code Word. The Acknowledge Bit is encoded in bit D14 regardless of the
`value of the Selector Field or Link Code Word encoding. If no Next Page information is to be sent, this bit
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this stanggrd.
`
`
`
`Aerohive - Exhibit 1025
`
`0262
`
`

`
`IEEE
`Std 802.3u-1995
`
`SUPPLEMENT TO 802.3:
`
`shall be set to logic one in the Link Code Word after the reception of at least three consecutive and consistent
`FLP Bursts (ignoring the Acknowledge bit value). If Next Page information is to be sent, this bit shall be set
`to logic one after the device has successfully received at least three consecutive and matching FLP Bursts
`(ignoring the Acknowledge bit value), and will remain set until the Next Page information has been loaded
`into the Auto-Negotiation Next Page register (register 7). In order to save the current received Link Code
`Word, this must be read from the Auto-Negotiation link partner ability register (register 6) before the Next
`Page of transmit information is loaded into the Auto-Negotiation Next Page register. After the COMPLETE
`ACKNOWLEDGE state has been entered, the Link Code Word shall be transmitted six to eight (inclusive)
`times.
`
`28.2.1 .2.5 Next Page
`
`Next Page (NP) is encoded in bit D15 regardless of the Selector Field value or Link Code Word encoding.
`Support for transmission and reception of additional Link Code Word encodings is optional. If Next Page
`ability is not supported, the NP bit shall always be set to logic zero. If a device implements Next Page ability
`and wishes to engage in Next Page exchange, it shall set the NP bit to logic one. A device may implement
`Next Page ability and choose not to engage in Next Page exchange by setting the NP bit to a logic zero. The
`Next Page function is defined in 28.2.3.4.
`
`28.2.1 .3 Transmit Switch function
`
`The Transmit Switch function shall enable the transmit path from a single technology-dependent PMA to the
`MDI once a highest common denominator choice has been made and Auto-Negotiation has completed.
`
`During Auto-Negotiation, the Transmit Switch function shall connect only the FLP Burst generator con-
`trolled by the Transmit State Diagram, figure 28-14, to the MDI.
`
`When a PMA is connected to the MDI through the Transmit Switch function, the signals at the MDI shall
`conform to all of the PHY’s specifications.
`
`28.2.2 Receive function requirements
`
`The Receive function detects the NLP sequence using the NLP Receive Link Integrity Test fLmction of figure
`28-17. The NLP Receive Link Integrity Test fiinction will not detect link pass based on carrier sense.
`
`The Receive fimction detects the FLP Burst sequence, decodes the information contained within, and stores
`the data in rx_link_code_word[l6: 1]. The Receive fimction incorporates a receive switch to con1rol connec-
`tion to the l00BASE-TX or IOOBASE-T4 PMAs in addition to the NLP Receive Link Integrity Test func-
`tion, excluding the l0BASE-T Link Integrity Test function present in a l0BASE-T PMA. If Auto-
`Negotiation detects link_status=READY from any of the technology-dependent PMAs prior to FLP Burst
`detection, the autoneg_wait_timer (28.3.2) is started. If any other technology-dependent PMA indicates
`link_status=READY when the autoneg_wait_timer expires, Auto-Negotiation will not allow any data ser-
`vice to be enabled and may signal this as a remote fault to the Link Partner using the base page and will flag
`this in the Local Device by setting the Parallel Detection Fault bit (6.4) in the Auto-Negotiation expansion
`register. If a l0BASE-T PMA exists above the Auto-Negotiation fimction, it is not permitted to receive MDI
`activity in parallel with the NLP Receive Link Integrity Test function or any other technology-dependent
`function.
`
`28.2.2.1 FLP Burst ability detection and decoding
`
`In figures 28-8 to 28-10, the symbol “t0=0” indicates the event that caused the timers described to start, and
`all subsequent times given are referenced from that point. All timers referenced shall expire within the range
`specified in table 28-8 in 28.3.2.
`
`This is arr24>,;rchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
`
`0263
`
`

`
`CSMA/CD
`
`IEEE
`Std 8D2.3u-1995
`
`The Receive function shall identify the Link Partner as Auto-Negotiation able if it receives 6 to 17 (inclu-
`sive) consecutive link pulses that are separated by at least flp_test_min_timer time (5-25 us) but less than
`flp_test_max_timer time (165—185 us) as shown in figure 28-8. The information contained in the FLP Burst
`that identifies the Link Partner as Auto-Negotiation able shall not be passed to the Arbitration function if the
`FLP Burst is not complete. The Receive fimction may use the FLP Burst that identifies the Link Partner as
`Auto-Negotiation able for ability matching if the FLP Burst is complete. However, it is not required to use
`this FLP Burst for any purpose other than identification of the Link Partner as Auto-Negotiation able. Imple-
`mentations may ignore multiple FLP Bursts before identifying the Link Partner as Auto-Negotiation able to
`allow for potential receive equalization time.
`
`clock
`
`flp_test_min_timer
`range
`
`data
`
`clock
`
`f|p_test_max_fimer
`P3099
`
`data
`
`
`
`to = 0 I15
`
`31.25 us
`
`62.5 us
`
`93.75 us
`
`125 us
`
`15525 "5
`
`187.5 us
`
`The Receive function captures and decodes link pulses received in FLP Bursts. The first link pulse in an FLP
`Burst shall be interpreted as a clock link pulse. Detection of a clock link pulse shall restart the
`data_detect_min_timer and data_detect_max timer. The data_detect_min/max_tirners enable the receiver to
`distinguish data pulses from clock pulses and logic one data fiom logic zero data, as follows:
`
`a)
`
`b)
`
`If, during an FLP Burst, a link pulse is received when the data_detect_min_timer has expired while the
`data_detect_max_timer has not expired, the data bit shall be interpreted as a logic one (figure 28-9).
`If, during an FLP Burst, a link pulse is received after the data_detect_max_timer has expired, the
`data bit shall be interpreted as a logic zero (figure 28-9) and that link pulse shall be interpreted as a
`clock link pulse.
`
`As each data bit is identified it is stored in the appropriate rx_link_code_word[16:1] element.
`
`data_detect_min_timer
`range
`
`clock
`
`data_detect_max_timer
`range
`
`data
`
`clock
`
`data
`
`
`
`to = 0 us
`
`31.25 ps
`
`62.5 us
`
`93.75 us
`
`125 us
`
`156.25 us
`
`187-5 us
`
`FLP Bursts conforming to the nlp_test_min_timer and nlp_test_max_timer timing as shown in figure 28-10
`shall be considered to have valid separation.
`
`28.2.2.2 NLP detection
`
`NLP detection is accomplished via the NLP Receive Link Integrity Test fimction in figure 28-17. The NLP
`Receive Link Integrity Test function is a modification of the original l0BASE-T Link Integrity Test func-
`tion (figure 14-6), where the detection of receive activity will not cause a transition to the LINK TEST
`PASS state during Auto-Negotiation. The NLP Receive Link Integrity Test function also incorporates the
`Technology-Dependent Interface requirements.
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
`
`0264
`
`

`
`IEEE
`Std 802.3u-1995
`
`SUPPLEMENT TO 802.3:
`
`n|p_test_min_timer
`range
`
`n|p_test_max_ imer
`range
`
`\
`FLP Burst
`FLPBurst \
`LT I L:
`t0=Oms
`5ms
`7ms
`16 ms
`50 ms
`150ms
`
`28.2.2.3 Receive Switch function
`
`The Receive Switch function shall enable the receive path from the MDI to a single technology—dependent
`PMA once a highest common denominator choice has been made and Auto-Negotiation has completed.
`
`During Auto-Negotiation, the Receive Switch function shall connect both the FLP Burst receiver controlled
`by the Receive state diagram, figure 28-15, and the NLP Receive Link Integrity Test state diagram, figure
`28-17, to the MDI. During Auto-Negotiation, the Receive Switch function shall also connect the 100BASE-
`TX and 100BASE-T4 PMA receivers to the MDI if the IOOBASE-TX and/or 100BASE-T4 PMAs are
`
`present.
`
`When a PMA is connected to the MDI through the Receive Switch function, the signals at the PMA shall
`conform to all of the PHY’s specifications.
`
`28.2.2.4 Link Code Word matching
`
`The Receive function shall generate abi1ity_match, acknow1edge_match, and consistency_match variables
`as defined in 28.3.1.
`
`28.2.3 Arbitration function requirements
`
`The Arbitration ftmction ensures proper sequencing of the Auto-Negotiation fimction using the Transmit
`fimction and Receive fimction. The Arbitration fimction enables the Transmit function to advertise and
`
`acknowledge abilities. Upon indication of acknowledgment, the Arbitration function determines the highest
`common denominator using the priority resolution fimction and enables the appropriate technology-depen-
`dent PMA via the Technology-Dependent Interface (28.2.6).
`
`28.2.3.1 Parallel detection function
`
`The Local Device detects a Link Partner that supports Auto-Negotiation by FLP Burst detection. The Paral-
`lel Detection fimction allows detection of Link Partners that support IOOBASE-TX, 100BASE-T4, and/or
`IOBASE-T, but do not support Auto-Negotiation. Prior to detection of FLP Bursts, the Receive Switch shall
`direct MDI receive activity to the NLP Receive Link Integrity Test state diagram,
`l00BASE-TX and
`100BASE-T4 PMAs, if present, but shall not direct MDI receive activity to the IOBASE-T or any other
`PMA. If at least one of the IOOBASE-TX, 100BASE-T4, or NLP Receive Link Integrity Test functions
`establishes link_status=READY, the LINK STATUS CHECK state is entered and the autoneg_wait_timer is
`started. If exactly one link_status=READY indication is present when the autoneg_wait_timer expires, then
`Auto-Negotiation shall set 1ink_control=ENABLE for the PMA indicating link_status=READY. If a PMA
`is enabled, the Arbitration function shall set link_control=DISABLE to all other PMAs and indicate that
`Auto-Negotiation has completed. On transition to the FLP LINK GOOD CHECK state from the LINK STA-
`
`This is arizltxrchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
`
`0265
`
`

`
`CSMA/CD
`
`IEEE
`Std 802.3u-1995
`
`TUS CHECK state the Parallel Detection fimction shall set the bit in the link partner ability register (register
`5) corresponding to the technology detected by the Parallel Detection function.
`
`NOTES
`
`l—Native 10BASE-T devices will be detected by the NLP Receive Link Integrity Test function, an integrated part of the
`Auto—Negotiation fimction. Hence, Parallel Detection for the 10BASE-T PMA is not required or allowed.
`2—When selecting the highest common denominator through the Parallel Detection fimction, only the half-duplex mode
`corresponding to the selected PMA may automatically be detected.
`
`28.2.3.2 Renegotiation function
`
`A renegotiation request from any entity, such as a management agent, shall cause the Arbitration fimction to
`disable all technology-dependent PMAs and halt any transmit data and link pulse activity until the
`break_link_tirner expires (28.3.2). Consequently, the Link Partner will go into link fail and normal Auto-
`Negotiation resumes. The Local Device shall resume Auto—Negotiation after the break_1ink_timer has
`expired by issuing FLP Bursts with the base page valid in tx_link_code_word[16:l].
`
`Once Auto—Negotiation has completed, renegotiation will take place if the Highest Common Denominator
`technology that receives link_control=ENABLE returns link_status=FAIL. To allow the PMA an opportu-
`nity to determine link integrity using its own link integrity test function, the link_fail_inhibit_timer qualifies
`the link_status=FAIL indication such that renegotiation takes place if the link_fail_inhibit_timer has expired
`and the PMA still indicates link_status=FAIL or link_status=READY.
`
`28.2.3.3 Priority Resolution function
`
`Since a Local Device and a Link Partner may have multiple common abilities, a mechanism to resolve which
`mode to configure is required. The mechanism used by Auto—Negotiation is a Priority Resolution fimction
`that predefines the hierarchy of supported technologies. The single PMA enabled to connect to the MDI by
`Auto—Negotiation shall be the technology corresponding to the bit in the Technology Ability Field common
`to the Local Device and Link Partner that has the highest priority as defined in annex 28B. This technology
`is referred to as the Highest Common Denominator, or HCD, technology. If the Local Device receives a
`Technology Ability Field with a bit set that is reserved, the Local Device shall ignore that bit for priority res-
`olution. Determination of the HCD technology occurs on entrance to the FLP LINK GOOD CHECK state.
`In the event that a technology is chosen through the Parallel Detection function, that technology shall be
`considered the highest common denominator O-ICD) technology. In the event that there is no common tech-
`nology, HCD shall have a value of “NULL,” indicating that no PMA receives link_control=ENABLE, and
`link_status_[HCD]=FAIL.
`
`28.2.3.4 Next Page function
`
`The Next Page fimction uses the standard Auto—Negotiation arbitration mechanisms to allow exchange of
`arbitrary pieces of data. Data is carried by optional Next Pages of information, which follow the transmis-
`sion and acknowledgment procedures used for the base Link Code Word. Two types of Next Page encodings
`are defined: Message Pages and Unformatted Pages.
`
`A dual acknowledgment system is used. Acknowledge (Ack) is used to acknowledge receipt of the informa-
`tion; Acknowledge 2 (Ack2) is used to indicate that the receiver is able to act on the information (or perform
`the task) defined in the message.
`
`Next Page operation is controlled by the same two mandatory control bits, Next Page and Acknowledge,
`used in the Base Link Code Word. Setting the NP bit in the Base Link Code Word to logic one indicates that
`the device is Next Page Able. If both a device and its Link Par1:ner are Next Page Able, then Next Page
`exchange may occur. If one or both devices are not Next Page Able, then Next Page exchange will not occur
`and, after the base Link Code Words have been exchanged, the FLP LINK GOOD CHECK state will be
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`0266
`
`t 1025
`
`Aerohive - Exhibit 1025
`
`0266
`
`

`
`IEEE
`Std 802.3u-1995
`
`SUPPLEMENT TO 802.3:
`
`entered. The Toggle bit is used to ensure proper synchronization between the Local Device and the Link
`Partner.
`
`Next Page exchange occurs after the base Link Code Words have been exchanged. Next Page exchange con-
`sists of using the normal Auto-Negotiation arbitration process to send Next Page messages. Two message
`encodings are defined: Message Pages, which contain predefined 11 bit codes, and Unformatted Pages.
`Unformatted Pages can be combined to send extended messages. If the Selector Field values do not match,
`then each series of Unformatted Pages shall be preceded by a Message Page containing a message code that
`defines how the following Unformatted Pages will be interpreted. If the Selector Field values match, then the
`convention governing the use of Message Pages shall be as defined by the Selector Field value definition.
`Any number of Next Pages may be sent in any order; however, it is recommended that the total number of
`Next Pages sent be kept small to minimize the link startup time.
`
`Next Page transmission ends when both ends of a link segment set their Next Page bits to logic zero, indicat-
`ing that neither has anything additional to transmit. It is possible for one device to have more pages to trans-
`mit than the other device. Once a device has completed transmission of its Next Page information, it shall
`transmit Message Pages with Null message codes and the NP bit set to logic zero while its Link Partner con-
`tinues to transmit valid Next Pages. An Auto-Negotiation able device shall recognize reception of Message
`Pages with Null message codes as the end of its Link Partner’s Next Page information.
`
`28.2.3.4.1 Next Page encodings
`
`The Next Page shall use the encoding shown in figures 28-11 and 28-12 for the NP, Ack, MP, Ack2, and
`T bits. The 11-bit field DlO—DO shall be encoded as a Message Code Field if the MP bit is logic one and an
`Unformatted Code Field if MP is set to logic zero.
`
`DO
`
`D1
`
`D2
`
`D3
`
`D4
`
`D5
`
`D6
`
`D7
`
`D8
`
`D9
`
`D10 D11 D12 D13 D14 D15
`
`Message Code Field
`
`3 w
`
`
`flfll
`Unformatted Code Field
`
`
`28.2.3.4.2 Next Page
`
`Next Page (NP) is used by the Next Page function to indicate whether or not this is the last Next Page to be
`transmitted. NP shall be set as follows:
`
`logic zero = last page.
`logic one = additional Next Page(s) will follow.
`
`This is arizegchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`D0
`
`D1
`
`D2
`
`D
`
`D4
`
`D5
`
`D6
`
`D7
`
`D8
`
`D9
`
`D10 D11 D12 D13 D14 D15
`
`Aerohive - Exhibit 1025
`
`0267
`
`

`
`CSMA/CD
`
`28.2.3.4.3 Acknowledge
`
`As defined in 28.2.1.2.4.
`
`28.2.3.4.4 Message Page
`
`IEEE
`Std 802.3u-1995
`
`Message Page (MP) is used by the Next Page fimction to differentiate a Message Page from an Unformatted
`Page. MP shall be set as follows:
`
`logic zero = Unformatted Page.
`logic one = Message Page.
`
`28.2.3.4.5 Acknowledge 2
`
`Acknowledge 2 (Ack2) is used by the Next Page function to indicate that a device has the ability to comply
`with the message. Ack2 shall be set as follows:
`
`logic zero = cannot comply with message.
`logic one = will comply with message.
`
`28.2.3.4.6 Toggle
`
`Toggle (T) is used by the Arbitration function to ensure synchronization with the Link Partner during Next
`Page exchange. This bit shall always take the opposite value of the Toggle bit in the previously exchanged
`Link Code Word. The initial value of the Toggle bit in the first Next Page transmitted is the inverse of bit 11
`in the base Link Code Word and, therefore, may assume a value of logic one or zero. The Toggle bit shall be
`set as follows:
`
`logic zero = previous value of the transmitted Link Code Word equalled logic one.
`logic one = previous value of the transmitted Link Code Word equalled logic zero.
`
`28.2.3.4.7 Message Page encoding
`
`Message Pages are formatted pages that carry a single predefined Message Code, which is enumerated in
`armex 28C. Two-thousand and forty-eight Message Codes are available. The allocation of these codes will
`be controlled by the contents of annex 28C. If the Message Page bit is set to logic one, then the bit encoding
`of the Link Code Word shall be interpreted as a Message Page.
`
`28.2.3.4.8 Message Code Field
`
`Message Code Field (M[10:0]) is an eleven bit wide field, encoding 2048 possible messages. Message Code
`Field definitions are shown in annex 28C. Combinations not specified are reserved for future use. Reserved
`combinations of the Message Code Field shall not be transmitted.
`
`28.2.3.4.9 Unformatted Page encoding
`
`Unformatted Pages carry the messages indicated by Message Pages. Five control bits are predefined, the
`remaining 11 bits may take on an arbitrary value. If the Message Page bit is set to logic zero, then the bit
`encoding of the Link Code Word shall be interpreted as an Unformatted Page.
`
`28.2.3.4.10 Unformatted Code Field
`
`Unformatted Code Field (U[l0:0]) is an eleven bit wide field, which may contain an arbitrary value.
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
`
`0268
`
`

`
`IEEE
`Std 802.3u-1995
`
`28.2.3.4.11 Use of Next Pages
`
`SUPPLEMENT TO 802.3:
`
`Both devices must indicate Next Page ability for either to commence exchange of Next Pages.
`a)
`If both devices are Next Page able, then both devices shall send at least one Next Page.
`b)
`c) Next Page exchange shall continue until neither device on a link has more pages to transmit as indi-
`cated by the NP bit. A Message Page with a Null Message Code Field value shall be sent if the
`device has no other information to transmit.
`
`e)
`
`d) A Message Code can carry either a specific message or information that defines how following
`Unformatted Page(s) should be interpreted.
`If a Message Code references Unformatted Pages, the Unformatted Pages shall immediately follow
`the referencing Message Code in the order specified by the Message Code.
`Unformatted Page users are responsible for controlling the format and sequencing for their Unfor-
`matted Pages.
`
`i)
`
`28.2.3.4.12 MII register requirements
`
`The Next Page Transmit register defined in 28.2.4.1.6 shall hold the Next Page to be sent by Auto-Negotia-
`tion. Received Next Pages may be stored in the Auto-Negotiation link partner ability register.
`
`28.2.3.5 Remote fault sensing function
`
`The Remote Fault function may indicate to the Link Partner that a fault condition has occurred using the
`Remote Fault bit and, optionally, the Next Page function.
`
`Sensing of faults in a device as well as subsequent association of faults with the Remote Fault bit shall be
`optional. If the Local Device has no mechanism to detect a fault or associate a fault condition with the
`received Remote Fault bit indication, then it shall transmit the Remote Fault bit with the value contained in
`the Auto-Negotiation advertisement register bit (4.13).
`
`A Local Device may indicate it has sensed a fault to its Link Partner by setting the Remote Fault bit in the
`Auto-Negotiation advertisement register and renegotiating.
`
`If the Local Device sets the Remote Fault bit to logic one, it may also use the Next Page function to specify
`information about the fault that has occurred. Remote Fault Message Page Codes have been specified for this
`purpose.
`
`The Remote Fault bit shall remain set until afier successfirl negotiation with the base Link Code Word, at
`which time the Remote Fault bit shall be reset to a logic zero. On receipt of a base Link Code Word with the
`Remote Fault bit set to logic one, the device shall set the Remote Fault bit in the MII status register (1.4) to
`logic one if the MII management function is present.
`
`28.2.4 Management function requirements
`
`The management interface is used to communicate Auto-Negotiation information to the management entity.
`If an M11 is physically implemented, then management access is via the MII Management interface. Where
`no physical embodiment of the M11 exists, an equivalent to MH registers 0, 1, 4, 5, 6, and 7 (clause 22) are
`recommended to be provided.
`
`28.2.4.1 Media Independent Interface
`
`The Auto-Negotiation function shall have five dedicated registers:
`
`a) MII control register (register 0).
`b)
`lVHI status register (register 1).
`
`This is ar124>g'chive IEEE Standard.
`
`It has been superseded by a later version of this standard.
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`
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`Std 802.3u-1995
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`c) Auto-Negotiation advertisement register (register 4).
`cl) Auto-Negotiation link partner ability register (register 5).
`e) Auto-Negotiation expansion register (register 6).
`
`If the Next Page fimction is implemented, the Auto-Negotiation Next Page Transmit Register (register 7)
`shall be implemented.
`
`28.2.4.1.1 Mll control register
`
`MII control register (register 0) provides the mechanism to disable/enable and/or restart Auto—Negotiation.
`The definition for this register is provided in 22.2.4.1.
`
`The Auto—Negotiation fimction shall be enabled by setting bit 0.12 to a logic one. If bit 0.12 is set to a logic
`one, then bits 0.13 and 0.8 shall have no effect on the link configuration, and the Auto-Negotiation process
`will determine the link configuration. If bit 0.12 is cleared to logic zero, then bits 0.13 and 0.8 will determine
`the link configuration regardless of the prior state ofthe link configuration and the Auto-Negotiation process.
`
`A PHY shall return a value of one in bit 0.9 until the Auto-Negotiation process has been initiated. The Auto-
`Negotiation process shall be initiated by setting bit 0.9 to a logic one. If Auto-Negotiation was completed
`prior to this bit being set, the process shall be reinitiated. If a PHY reports via bit 1.3 that it lacks the ability
`to perform Auto-Negotiation, then this bit will have no meaning, and should be written as zero. This bit is
`self-clearing. The Auto-Negotiation process shall not be affected by clearing this bit to logic zero.
`
`28.2.4.1.2 Mll status register
`
`The MII status register (register 1) includes information about all modes of operations supported by the
`Local Device’s PHY, the status ofAuto—Negotiation, and whether the Auto—Negotiation fimction is supported
`by the PHY or not. The definition for this register is provided in 22.2.4.2.
`
`When read as a logic one, bit 1.5 indicates that the Auto-Negotiation process has been completed, and that
`the contents of registers 4, 5, and 6 are valid. When read as a logic zero, bit 1.5 indicates that the Auto-Nego-
`tiation process has not been completed, and that the contents of registers 4, 5, and 6 are meaningless. A PHY
`shall return a value of zero in hit 1.5 if Auto-Negotiation is disabled by clearing bit 0.12. A PHY shall also
`return a value of zero in bit 1.5 if it lacks the ability to perform Auto-Negotiation.
`
`When read as logic one, bit 1.4 indicates that a remote fault condition has been detected. The type of fault as
`well as the criteria and method of fault detection is PHY specific. The Remote Fault bit shall be implemented
`with a latching fimction, such that the occurrence of a remote fault will cause the Remote Fault bit to
`become set and remain set until it is cleared. The Remote Fault bit shall be cleared each time register 1 is
`read via the management interface, and shall also be cleared by a PHY reset.
`
`When read as a one, bit 1.3 indicates that the PHY has the ability to perform Auto-Negotiation. When read as
`a logic zero, bit 1.3 indicates that the PHY lacks the ability to perfonn Auto-Negotiation.
`
`28.2.4.1 .3 Auto-Negotiation advertisement register (register 4) (RIW)
`
`This register contains the Advertised Ability of the PHY. (See table 28-2). The bit definition for the base
`page is defined in 28.2.1.2. On power—up, before Auto—Negotiation starts, this register shall have the follow-
`ing configuration: The Selector Field (4.4:0) is set to an appropriate code as specified in armex 28A. The
`Acknowledge bit (4.14) is set to logic zero. The Technology Ability Field (4.12:5) is set based on the values
`set in the M11 status register (register 1) (l.l5:11) or equivalent.
`
`Only the bits in the Technology Ability Field that represent the technologies supported by the Local Device
`may be set. Any of the Technology Ability Field bits that may be set can also be cleared by management
`
`This is an Archive IEEE Standard.
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`It has been superseded by a later version of this standard.
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`SUPPLEMENT TO 802.3:
`
`Table 28-2—Advertisement register bit definitions
`
`
`
`before a renegotiation. This can be used to enable management to Auto-Negotiate to an alternate common
`mode.
`
`The management entity may initiate renegotiation with the Link Partner using alternate abilities by setting
`the Selector Field (4.4:0) and Technology Ability Field (4.12:5) to indicate the preferred mode of operation
`and setting the Restart Auto—Negotiation bit (0.9) in the control register (register 0) to logic one.
`
`Any writes to this register prior to completion ofAuto—Negotiation as indicated by bit 1.5 should be followed
`by a renegotiation for the new values to be properly used for Auto—Negotiation. Once Auto—Negotiation has
`completed, this register value may be examined by software to determine the highest common denominator
`technology.
`
`28.2.4.1.4 Auto-Negotiation link partner ability register (register 5) (R0)
`
`All of the bits in the Auto—Negotiation link partner ability register are read only. A write to the Auto—Negoti-
`ation link partner ability register shall have no effect.
`
`This register contains the Advertised Ability of the Link Partner’s PHY. (See tables 28-3 and 28-4.) The bit
`definitions shall be a direct representation of the received Link Code Word (figure 28-7). Upon successful
`completion of Auto—Negotiation, status register (register 1) Auto—Negotiation Complete bit (1.5) shall be set
`to logic one. If the Next Page fimction is supported, the Auto—Negotiation link partner ability register may be
`used to store Link Partner Next Pages.
`
`Table 28-3—Link partner ability register bit definitions (Base Page)
`
`
`
`The values contained in this register are only guaranteed to be valid once Auto—Negotiation has successfully
`completed, as indicated by bit 1.5 or, if used with Next Page exchange, after the Page Received bit (6.1) has
`been set to logic one.
`
`This is anzggchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
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`
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`Aerohive - Exhibit 1025
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`Std 802.3u-1995
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`Table 28-4—Link partner ability register bit definitions (Next Page)
`
`Description
`
`See 28.2.3.4
`
`Next Page
`
`Acknowledge
`
`Message Page
`
`Acknowledge 2
`
`Toggle
`
`Message/Unfonnatted Code
`Field
`
`See 28.2.3.4
`
`See 28.2.3.4
`
`See 28.2.3.4
`
`See 28.2.3.4
`
`See 28.2.3.4
`
`NOTE—If this register is used to store Link Partner Next Pages, the p