88e3015 Marvell Semiconductor, Inc., 88e3015 Datasheet - Page 81

• Manufacturer Part Number: 88e3015
• Description: Integrated 10/100 Fast Ethernet Transceiver
• Manufacturer: Marvell Semiconductor, Inc.

Table 51:
Copyright © 2006 Marvell
October 26, 2006, Advance
B i ts
15
14:13
12:8
7:0
F i e l d
EnVCT
VCTTst
AmpRfln
DistRfln
Register 26
VCT™ Register for MDIP/N[0] Pins
M o d e
R/W,
SC
RO
RO
RO
Document Classification: Proprietary Information
H W
R s t
0x0
0x0
0x00
0x00
CONFIDENTIAL
S W
R s t
0x0
Retain
Retain
Retain
D e s c r i p t io n
Enable VCT
0 = VCT completed
1 = Run VCT
After running VCT once, bit 15 = 0 indicates VCT com-
pleted.
The cable status is reported in the VCTTst bits in regis-
ters 26 and 27.
Refer to the Virtual Cable Tester
VCT Test Status
These VCT test status bits are valid after completion of
VCT.
00 = Valid test, normal cable (no short or open in cable)
01 = Valid test, short in cable (Impedance < 33 ohm)
10 = Valid test, open in cable (Impedance > 333 ohm)
11 = Test fail
Amplitude of Reflection
The amplitude of reflection is stored in these register
bits. These amplitude bits range from 0x07 to 0x1F.
0x1F = Maximum positive amplitude
0x13 = Zero amplitude
0x07 = Maximum negative amplitude
These bits are valid after completion of VCT (bit 15) and
if the VCT test status bits (bits 14:13) have not indicated
test failure.
Distance of Reflection
These bits refer to the approximate distance (± 1m) to
the open/short location, measured at nominal conditions
(room temperature and typical VDDs)
These bits are valid after completion of VCT (bit 15) and
if the VCT test status bits (bit 14:13) have not indicated
test failure.
Doc. No. MV-S103657-00, Rev. C
®
feature.
Page 81