ICS1892 datasheet(38/148 Pages) ICST

38 / 148 page

ICS1892, Rev. D, 2/26/01

February 26, 2001

Chapter 7

Functional Blocks

ICS1892 Data Sheet

7.2.4

Auto-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

7.2.4.1

Auto-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).

7.2.4.2

Auto-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 self-

clearing 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.

ICS1892 数据表(PDF) 38 Page - Integrated Circuit Systems

ICS1892 数据表(HTML) 38 Page - Integrated Circuit Systems

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