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Cortina Systems LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
LXT9785/LXT9785E
Datasheet
249241, Revision 11.0
16 April 2007
7.0 Register Definitions
Table 93
Port Configuration Register (Address 16, Hex 10)
Bit
Name
Description
Type 1
Default
15
Reserved
Write as 0, ignore on Read
R/W
0
14
Link Disable
0 = Normal operation
1 = Force link pass (sets appropriate registers and LEDs
to pass)
Note:
Setting this bit in 100 Mbps mode by-passes the
descrambler lock requirement to establish link and forces
the link to the link-good state. Setting this bit produces
unreliable results if the descrambler is not locked,
R/W
0
13
Transmit Disable
0 = Normal operation
1 = Disable twisted-pair transmitter
R/W
0
12
Bypass Scramble
(100BASE-TX)
0 = Normal operation
1 = Bypass scrambler and descrambler
R/W
0
11
Reserved
Write as 0, ignore on Read
R/W
0
10
Jabber
(10BASE-T)
0 = Normal operation
1 = Jabber function is enabled; however, jabber status
reporting to Register bit 1.1 is disabled
R/W
0
9
Reserved
Write as 0, ignore on Read.
R/W
0
8
TP Loopback
(10BASE-T)
0 = Normal operation
1 = Disable twisted-pair loopback during half-duplex
operation
Note:
Valid function in SMII and S-SMII modes only.
R/W
1
7
Reserved
Write as 1, ignore on Read
R/W
1
6
Reserved
Write as 0, ignore on Read
R/W
0
5
Preamble Enable
10 Mbps
0 = No preamble (default)
1 = Preamble enabled
Note:
Default for BGA15 package is 0.
R/W
LSHR2,4
100
Mbps
No effect
N/A
4
Reserved
Write as 0, ignore on Read
R/W
0
3
Reserved
Write as 0, ignore on Read
R/W
0
2
Far End Fault
Transmission
Enable
0 = Disable Far End Fault transmission
1 = Enable Far End Fault transmission
R/W
1
Invalid for
BGA15
Write as '0', ignore on Read (BGA15).
1. R/W = Read/Write
2. LSHR = Default value is derived from a single device input pin state or a group of device input pin states as
the pin(s) are latched at startup or hardware reset.
3. The default value of Register bit 16.0 is determined by the G_FX/TP_L pin.
If G_FX/TP_L is tied Low, the default value of Register bit 16.0 = 0. If G_FX/TP_L is not tied Low, the
default value of Register bit 16.0 = 1. The BGA15 package does not have a G_FX/TP_L hardware
configuration pin.
4. The default value of Register bit 16.5 is determined by the PREASEL pin. The BGA15 package does not
have a PREASEL hardware configuration pin and has a default of 0.
5. The BGA15 package does not support fiber. Default for the BGA15 package is 0.
6. NA means the bits do not have a default value and may initially contain any value.