LAN9354 datasheet(98/487 Pages) MICROCHIP

98 / 487 page

LAN9354

DS00001926B-page 98

 2015 Microchip Technology Inc.

9.2.15.2

Matched Cable Diagnostics

Matched cable diagnostics enable cable length estimation on 100 Mbps-linked cables of up to 120 meters. If there is an

active 100 Mb link, the approximate distance to the link partner can be estimated using the PHY x Cable Length Register

(PHY_CABLE_LEN_x). If the cable is properly terminated, but there is no active 100 Mb link (the link partner is disabled,

nonfunctional, the link is at 10 Mb, etc.), the cable length cannot be estimated and the PHY x Cable Length Register

(PHY_CABLE_LEN_x) should be ignored. The estimated distance to the link partner can be determined via the Cable

Length (CBLN) field of the PHY x Cable Length Register (PHY_CABLE_LEN_x) using the lookup table provided in

Table 9-9. The typical cable length measurement margin of error for a matched cable case is +/- 20 m. The matched

cable length margin of error is consistent for all cable types from 0 to 120 m.

CAT 5 Cable, 0-100 m

CAT 6 Cable, 101-160 m

CAT 5E Cable, 101-160 m

CAT 5 Cable, 101-160 m

TABLE 9-8:

TYPICAL MEASUREMENT ERROR FOR SHORTED CABLE (+/- METERS)

PHYSICAL DISTANCE

TO FAULT

SELECTED PROPAGATION CONSTANT

PSHORT =

Unknown

PSHORT =

CAT 6

PSHORT =

CAT 5E

PSHORT =

CAT 5

CAT 6 Cable, 0-100 m

CAT 5E Cable, 0-100 m

CAT 5 Cable, 0-100 m

CAT 6 Cable, 101-160 m

CAT 5E Cable, 101-160 m

CAT 5 Cable, 101-160 m

TABLE 9-9:

MATCH CASE ESTIMATED CABLE LENGTH (CBLN) LOOKUP

CBLN Field Value

Estimated Cable Length

0 - 3

517

627

738

849

959

TABLE 9-7:

TYPICAL MEASUREMENT ERROR FOR OPEN CABLE (+/- METERS)

LAN9354 Datasheet(PDF) 98 Page - Microchip Technology

LAN9354 Datasheet(HTML) 98 Page - Microchip Technology

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

Datasheet Download

Link URL