LAN9211 datasheet(72/147 Pages) SMSC

72 / 147 page

High-Performance Small Form Factor Single-Chip Ethernet Controller with HP Auto-MDIX Support

Datasheet

Revision 2.9 (03-01-12)

SMSC LAN9211

DATASHEET

performance mode of operation supported by both sides. Auto-negotiation is fully defined in clause 28

of the IEEE 802.3 specification.

Once auto-negotiation has completed, information about the resolved link can be passed back to the

controller via the internal Serial Management Interface (SMI). The results of the negotiation process

are reflected in the Speed Indication bits in register 31, as well as the Link Partner Ability Register

(Register 5).

The auto-negotiation protocol is a purely physical layer activity and proceeds independently of the MAC

controller.

The advertised capabilities of the PHY are stored in register 4 of the SMI registers. The default

advertised by the PHY is determined by user-defined on-chip signal options.

The following blocks are activated during an Auto-negotiation session:

Auto-negotiation (digital)

100M ADC (analog)

100M PLL (analog)

100M equalizer/BLW/clock recovery (DSP)

10M SQUELCH (analog)

10M PLL (analog)

10M Transmitter (analog)

When enabled, auto-negotiation is started by the occurrence of one of the following events:

Hardware reset

Software reset

Power-down reset

Link status down

Setting register 0, bit 9 high (auto-negotiation restart)

On detection of one of these events, the PHY begins auto-negotiation by transmitting bursts of Fast

Link Pulses (FLP). These are bursts of link pulses from the 10M transmitter. They are shaped as

Normal Link Pulses and can pass uncorrupted down CAT-3 or CAT-5 cable. A Fast Link Pulse Burst

consists of up to 33 pulses. The 17 odd-numbered pulses, which are always present, frame the FLP

burst. The 16 even-numbered pulses, which may be present or absent, contain the data word being

transmitted. Presence of a data pulse represents a “1”, while absence represents a “0”.

The data transmitted by an FLP burst is known as a “Link Code Word.” These are defined fully in IEEE

802.3 clause 28. In summary, the PHY advertises 802.3 compliance in its selector field (the first 5 bits

of the Link Code Word). It advertises its technology ability according to the bits set in register 4 of the

SMI registers.

There are 4 possible matches of the technology abilities. In the order of priority these are:

100M full-duplex (Highest priority)

100M half-duplex

10M full-duplex

10M half-duplex

If the full capabilities of the PHY are advertised (100M, full-duplex), and if the link partner is capable

of 10M and 100M, then auto-negotiation selects 100M as the highest performance mode. If the link

partner is capable of half and full-duplex modes, then auto-negotiation selects full-duplex as the highest

performance operation.

LAN9211 数据表(PDF) 72 Page - SMSC Corporation

LAN9211 数据表(HTML) 72 Page - SMSC Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载