gigabit ethernet utp-5 phy pmc-sierra,...

19/23/96

PMC-Sierra, Inc.

IEEE 802.3z Task Force, Couer d’Alene, Sept. 9th-11th, 1996

Gigabit Ethernet UTP-5 PHY

• Contacts:– Barry Hagglund Manager Product Research (presenting)– Vernon Little Manager LAN Marketing– Brian Gerson Manager Analog Development– Steve Dabecki Senior Designer, Gigabit PHY

PMC-Sierra, Inc.105-8555 Baxter PlaceBurnaby, B.C. Canada V5A 4V7tel: 604.415.6000

29/23/96

PMC-Sierra, Inc.


Proposed Gigabit Ethernet PHY

• Gigabit Ethernet PHY interface;– 50 m short-haul - Full Duplex UTP-5, 4-pair interface

» one device, roadmap to 100 m– 100 m intermediate - Full Duplex UTP-5, 8-pair interface

» two devices plus GMII mux logic, roadmap to 200 m

• Basic Elements:– Gigabit MII between MAC and PHY (G-MII - ‘jimmy’)– Pair division multiplexing– 4 Level Line encoding– Zero state frame delineation (4LZS)– Data Scrambling for spectrum management– Clock and data recovery– Bit and word synchronization

• Continuous time analog, based on existing technology

39/23/96

PMC-Sierra, Inc.


4 Pair vs. 8 Pair

Gigabit Ethernet InterfaceGMII

125 MB/s

4-pairsUTP-5

Gigabit Ethernet Interface

GMMI-MUX

GMII125 MB/s

4-pairsUTP-5

4-pairsUTP-5

Gigabit Ethernet Interface

4-Pairs50m

8-Pairs100m

49/23/96

PMC-Sierra, Inc.


4-Level Code

• When coding n bits per pulse, for a bit rate of B, the pulse (symbol) rate is B/n

• 4 Level gives 2 bits per symbol– 500 Mbits transmits in 250 Mbaud

• One dimensional code - one degree of complexity

4-PAM Eye

- 3 . 0 0

- 1 . 0 0

1.00

3.00

NRZ vs. 4-PAM (2B1Q) Line Codes

0

0.2

0 .4

0 .6

0 .8

1

1 .2

1 .4

B/2 B

4LZS

NRZ

4 Level EyeNRZ vs. 4LZS Spectrum at bit rate ‘B’

59/23/96

PMC-Sierra, Inc.


Quaternary Slicer SNR

• Intrinsic coding power density at slicer is the symbol variance

• SNR = σ2s / σ2n ; ∆SNR = σ2s2B1Q / σ2sNRZ

• σ2s = 1/Lc∑i<ei2>

• σ2s2B1Q = 1/4{(-3)2+(-1)2+(1)2+(3)2} = 5• σ2sNRZ = 1/2{(-1)2+(1)2} = 1

• ∆SNR = σ2s2B1Q / σ2sNRZ= 10 log(5/1) = 7 dB

4 levels require 7dB higher SNR than does NRZ for same distance & same symbol rate

69/23/96

PMC-Sierra, Inc.


Relative Noise Immunity

• Flat channel noise power is proportional to the symbol rate [1/T]

– ∆σnflat = - 10 log [T2B1Q/TNRZ]= 2 dB @ 250 Mbaud vs. 155 Mbit NRZ

• Self-NEXT noise power is proportional to the cubed square root of the symbol rate [T]3/2

– ∆σnsnext = - 15 log [T2B1Q/TNRZ] = 3 dB @ 250 Mbaud vs. 155 Mbit NRZ

• Pair-pair NEXT noise power is frequency and cable geometry dependent

– N(ƒ) = χ ƒ 3/2 G(ƒ) ; χ = 6.31 x 10-7 for Category 5= 3 dB @ 250 Mbaud 2B1Q vs. 155 Mbit NRZ

79/23/96

PMC-Sierra, Inc.


Distance vs. Bit Rate

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

3 5 0

155.0 622.0 1000.0 1250.0

Single Reach (m)

Dual Reach (m)

PHY Comparisons

Capacity( M b / s )

gReach( m )

Reach( m )

CodingTechnique

155.0 1 0 5 3 5 0 * NRZ 155 UTP622.0 7 7 2 4 5 4LZS 622 UT

1 0 0 0 . 0 5 0 9 9 4LZS 10001250.0 3 3 7 6 8B10B 1000

Reach is more sensitive to symbol period than multi-level code

89/23/96

PMC-Sierra, Inc.


Modelled Eye Diagram: 20m UTP-5

• Unequalized Eye is open at 20m

• Simple equalization will allow operation to 50m

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

x 10−8

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Time (seconds)

Vol

ts

Eye Diagram at 20m on UTP−5 Cable

99/23/96

PMC-Sierra, Inc.


Modelled Eye Diagram: 20m & Magnetics

• Significant difference in eye opening

• Modelled with 266 F/C magnetics

• Lab work with Pulse PE65508 shows promise

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

x 10−8

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0.55

0.6

0.65

109/23/96

PMC-Sierra, Inc.


Experimental Eye Diagram: 20m UTP-5

• Unequalized Eye at end of cable

• 20 meters Belden “DataTwist-5” 1583B cable

• 2x3 meter AMP “Netconnect” patch cords

• PRBS 27-1

119/23/96

PMC-Sierra, Inc.


Experimental Eye Diagram: 26m UTP-5

• Unequalized Eye after Rx buffer

• 26 meters AT&T “SystiMax” 1061A cable

• 2x3 meter AMP “Netconnect” patch cords

• PRBS 27-1

• Zero Bit Errors on 15 minute intervals (10-7)

129/23/96

PMC-Sierra, Inc.


Spectrum Management

• For a similar launch level 4LZS engery is spread over a wider areaHence, lower energy at individual spectral lines

• Use of a scrambler spreads the energy across the spectrum, reducing the energy for radiation at a spectral line.

0

0.1

0 .2

0 .3

0 .4

0 .5

0 .6

0 .7

0 .8

0 .9

1

0

12

25

38

51

64

77

90

10

3

11

6

12

9

14

2

15

5

16

7

18

0

19

3

20

6

21

9

23

2

24

5

25

8

27

1

28

4

29

7

31

0

32

2

150 Mb NRZ 4Pai r_FCC

4LZS

NRZ

139/23/96

PMC-Sierra, Inc.


Frame Handling

• Bytes from GMII word byte mutliplexed on different pairs

• IDLE pattern maintains bit and word synch• IDLE to PREAMBLE code delimits start of

frame• Zero State signalling delimits end of frame

– EOF turns off transmitter for one byte (4 quats)– Receiver requires quiescent detection comparators and

digital decoding

• IDLE codes could be used to indicate ESCAPE’s– eg. IDLE defined over 3 quats with 4th used for codes

• IPG used for IDLE codes and Zero State– minimum IPG > 96 bits = 12 bytes– in 8 pair system - 3 bytes per Tx pair - 1 ZS & 2 IPG Bytes

149/23/96

PMC-Sierra, Inc.


Gigabit Media Independent Interface (G-MII)

• Generalize 802.3u MII for Fast Ethernet• 8-bit wide data, clocked at 125 MHz

– TX_ER RX_ER CRSTX_EN RX_DV COLTX_CLK RX_CLK MDCTXD[7:0] RXD[7:0] MDIO

– 26 pins total – ‘Flow through timing’ - Clocks transmitted with data

• 16 bit data also considered– 44 pins total– Octet Identification required

159/23/96

PMC-Sierra, Inc.


G-MII Timing

• 8-bit Timing (Odd number of bytes)

• PHY transmitter sources clock; clock flows back with data to PHY

TX_CLK

TX_EN

TXD[7:0] B1 B2 B3 B4 B5 B6 B7 B97 B98 B99

B1 - B7 B8 B9 - B14 B15 - B20 B21 - B22

PRE SDF DA SA LEN DAT CRS

B23 - B95 B96 - B99

FRAME

CRS

IDLIDLIDL

PHYMAC

169/23/96

PMC-Sierra, Inc.


Gigabit PHY Block Diagram

UTP-5 Facility

UTP-5 Facility

GigabitMII

Even Framer/Scrambler

End of Frame Logic

4LZSEncoder

4LZSEncoder

Parallel-Serial

Parallel-Serial

Odd Framer/Scrambler

Even Framer/Descrambler

Equalizer4LZSDecoder

Serial-Parallel

Odd Framer/Descrambler

Equalizer4LZS

DecoderSerial

-Parallel

TransmitFilter

TransmitFilter

Transmit

Receive

G-MII

End of Frame Logic

End of Frame Logic

End of Frame Logic

179/23/96

PMC-Sierra, Inc.


Ongoing Work

• BER performance over temperature• Confirm spectral and FCC results• ‘ESCAPE’ words required

– Error conditions, TSC ?

• DC balance requirements– Decision feedback at receiver vs. transmitter RDS correction

• Transmit templates and slicing levels

GigabitPHY

2x to 3x Fast Ethernet $based on existing technology

189/23/96

PMC-Sierra, Inc.


Supplementary Material

199/23/96

PMC-Sierra, Inc.


RJ-45 Pin Assignment (DTE)

1 - Tx1

2 - Tx1

3 - Rx1

4 - 5 -6 - Rx1

7 -8 -

100BaseT

1 - Tx1

2 - Tx1

3 - Rx1

4 - Rx2

5 - Rx2

6 - Rx1

7 - Tx2

8 - Tx2

Proposed1000BaseT

Pair 3

Pair 2

Pair 1

Pair 4

Pair 2

Pair 3

Pair 1

Pair 4

T568A T568B

1 - Tx1

2 - Tx1

3 - 4 - 5 -6 - 7 - Rx1

8 - Rx1

ATM-UTP

209/23/96

PMC-Sierra, Inc.


4LZS Code Assignment

• QPSK & ISDN proven grey code assignment• Equal Hamming distance between symbols

– Electrical Levels subject to verification

Code Bit Pairs Vnom (mV) Vmin Vmax

+ 3 1 0 8 0 0 7 0 0 Vcc+200+ 1 1 1 5 0 0 4 0 0 6 0 0- 1 0 1 2 5 0 2 0 0 3 0 0- 3 0 0 Vcc - 200 1 0 0

219/23/96

PMC-Sierra, Inc.


Reach Calculations

Single Bundle

ƒc Attenuation Sel f -NEXT

NEXTAttenuation

SNR Reach

NRZ 155 UTP 1 5 5 77.5 0 19.1 0 .0 0 .0 0 .0 19.1 105.04LZS 622 UTP 3 1 1 77.75 7 19.1 0 .0 0 .0 0 .0 26.2 76.6

4LZS 1000BaseT 5 0 0 1 2 5 7 24.9 2 .1 3 .1 3 .1 40.2 4 9 . 98B10B 1000BaseT 6 2 5 312.5 7 42.0 3 .0 4 .6 4 .6 61.1 32.8

Dual Bundle

ƒc Attenuation Sel f -NEXT

NEXTAttenuation

∂SNR Reach

NRZ 155 UTP 77.5 38.75 0 13.1 - 3 . 0 - 4 . 5 - 4 . 5 1 .1 1819.44LZS 622 UTP 155.5 38.88 7 13.2 - 3 . 0 - 4 . 5 - 4 . 5 8 .2 245.2

4LZS 1000BaseT 2 5 0 62.5 7 17.0 - 0 . 9 - 1 . 4 - 1 . 4 20.3 9 9 . 08B10B 1000BaseT 312.5 78.13 7 19.2 0 .0 0 .1 0 .1 26.3 76.2

229/23/96

PMC-Sierra, Inc.


EIA/TIA-568 Specs for UTP

• Characterized to 100 MHz• NEXT and Loss limited in length and frequency• Empirical results show headroom

EIA/TIA-568 Worst-Case Propagation Loss (Lpn) at 20° C

Cable Type dB loss per 100mFrequency

range (MHz)

Category 3 7.07√ƒ + 0.73 ƒ 2.33√ƒ + .23ƒ 1.20% 0.3 ≤ ƒ ≤ 16

Category 4 6.4 √ƒ + 0.08ƒ 2.10√ƒ + .026ƒ 0.30% 0.3 ≤ ƒ ≤ 20

Category 5 6.4√ƒ + 0.04ƒ 1.97√ƒ + 0.023ƒ 0.30% 0.3 ≤ ƒ ≤ 100

EIA/TIA-568 Worst-Case NEXT Loss (Lxn)

Cable TypedB pair-pair

NEXT lossConnecting HW

NEXT lossFrequency

range (MHz)

Category 3 7.94 x 10-5 41 - 15 log ƒ 58 - 15 log ƒ ƒ ≤ 16

Category 4 2.51 x 10-6 56 - 15 log ƒ 70 - 15 log ƒ ƒ ≤ 20

Category 5 6.31 x 10-7 64-15 log(ƒ/0.77) 80 - 15 log ƒ ƒ ≤ 100

239/23/96

PMC-Sierra, Inc.


Cable Model Match to 568

100

101

102

103

−20

−15

−10

−5

0Magnitude plot of single sided cable transfer function (w/o magnetics)

Frequency (Hertz)

Mag

nitu

de (

dB) Measured Result −>

<− TIA Result

249/23/96

PMC-Sierra, Inc.


Received Data - 155 Mbit/s

Data eye after 50m of cable

Data eye after 120m of cable

259/23/96

PMC-Sierra, Inc.


Equalized Receiver - 155 Mbit/s

50m cable 120m cable

269/23/96

PMC-Sierra, Inc.


FCC Radiated Emission Limits

• Radiated Emission Limits

Frequency (MHz)

Fie

ld

Str

en

gth

(d

BµV

/m)

35.0

40.0

45.0

50.0

55.0

60.0

65.0

1 0 1 0 0 1 0 0 0

FCC

CISPR 22

CISPR 22

Measurement Distance - 3m

Class B

Class A

Part 15

EN55022

Frequency (MHz)

Fie

ld

Str

en

gth

(d

BµV

/m)

25.0

30.0

35.0

40.0

45.0

50.0

55.0

1 0 1 0 0 1 0 0 0

Class A

Class B

FCC

CISPR 22

FCCCISPR 22

CIPSR - Comite International Spécial des Perturbations Radio-électriques

279/23/96

PMC-Sierra, Inc.


FCC Ambient Environment

• Horizontal Antennae

289/23/96

PMC-Sierra, Inc.


FCC Ambient Environment

• Vertical Antennae

299/23/96

PMC-Sierra, Inc.


Workstation Radiated

B C

D

EF G J K L N P

• Horizontal Antennae

309/23/96

PMC-Sierra, Inc.


Workstation Radiated


A

BC D

E F G H I J K L MO P

Q

319/23/96

PMC-Sierra, Inc.


155-UTP Radiated

A B C E

F

H

• Horizontal Antenna

329/23/96

PMC-Sierra, Inc.


155-UTP Radiated


D

E

F

G

gigabit ethernet utp-5 phy pmc-sierra,...

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