HBCU-5710R Datasheet, PDF (21/25 Pages) AVAGO TECHNOLOGIES LIMITED – Designed for Industry-Standard MSA-Compliant, Small Form Factor Pluggable (SFP) Ports

Table 21: Register 28 (Cable Diagnostic 2)
Bit
Name
28.15
Enable Cable
R/W
Diagnostic Test
Description
1 = Enable test
0 = disable test
Hardware
Reset
0
28.14:13 Status
RO
28.12:8
RO
Reflected
Magnitude
28.7:0 Distance
RO
11 = Test fail
10 = Open detected in twisted pair
01 = Short detected in twisted pair
00 = No short or open detected in twisted
pair
11111 = 1 V
10000 = 0 V
00000= -1 V
Distance to the short or open
00
00000
00000000
Software
Reset
0
00
00000
00000000
Details
The test can only be performed
when the link is down. If the
link partner is trying to auto-
negotiate or if the link partner
is sending out idle link pulses,
the test will proceed.
The twisted pair under test is
specified in register 22.
The twisted pair under test is
specified in register 22.
The distance is given in meters
by 13/16 * (decimal equivalent
of 28.7:0) + 32 .The twisted
pair under test is specified in
register 22. If no short or open
is detected, these bits are 0’s.
Table 22: Registers 29-30 (Specific Function Registers)
Specific function registers are used to enable special functions such as packet generator, CRC error check and external
loopback.
21