Marvell 88E3015 Manual page 82

88E3015/88E3018
Integrated 10/100 Fast Ethernet Transceiver
Table 52: VCT™ Register for MDIP/N[1] Pins
Register 27
B i ts F i el d
15 Reserved
14:13 VCTTst
12:8 AmpRfln
7:0 DistRfln
Doc. No. MV-S103657-00, Rev. D
Page 82
M o d e H W S W
R s t R s t
RO Always Always
0 0
RO 0x0 Retain
RO 0x00 Retain
RO 0x00 Retain
Document Classification: Proprietary Information
D e s c r i p t io n
Reserved
VCT Test Status
The 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 VCT test status bits (bit 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 VCT test status bits (bits 14:13) have not indicated test
failure.
Copyright © 2008 Marvell
January 4, 2008, Advance