LXT9785 Datasheet, PDF (214/226 Pages) Intel Corporation – Advanced 8-Port 10/100 Mbps PHY Transceivers

LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
Table 99. Trim Enable Register (Address 27, Hex 1B) (Sheet 1 of 2)
Bit Name
Description
15:13
12
Reserved
Reserved
11:10
Per-Port
Rise Time
Control
Write as 0, ignore on Read
Write as 0, ignore on Read.
00 = 3.3 ns
01 = 3.6 ns
10 = 3.9 ns
11 = 4.2 ns
Type⁵
R
R/W
Default
N/A
0
R/W LSHR^1,2
NOTE: Values represent nominal load conditions.
9
AMDIX_EN
0 = Disable auto MDI/MDIX
1 = Enable auto MDI/MDIX
R/W LSHR^1,3
8
MDIX
0 = MDI, transmit on pair A (TPFINn/TPFIPn) and receive on
pair B (TPFONn/TPFOPn)
1 = MDIX transmit on pair B (TPFONn/TPFOPn) and receive
on pair A (TPFINn/TPFIPn)
R/W
LSHR^1,4
NOTE: Manual MDI/MDIX selection (This bit is ignored when
Register bit 27.9 = 1).
NOTE: BGA15 does not support the MDIX hardware
configuration.
0 = Disable analog loopback
1 = Enable analog loopback (twisted-pair transmit outputs are
7
Analog
Loopback
active)
R/W
0
NOTE: In fiber mode, SD for the port must be asserted.
DTE Discovery Process Enable.
0 = Disable DTE discovery process
6
Dis_EN
1 = Enable DTE discovery process
Restart auto-negotiation after writing to this bit to ensure
proper operation.
R/W
0
5
Reserved Write as 0, ignore on Read.
R/W
0
Power Enable (Requires Auto-Negotiation Enable
Register bit 0.12 = 1).
4
Power_EN ^{0 = Remote-Power DTE not discovered; process may not be}
R
0
complete.
1 = Potential Remote-Power DTE discovered; indication to
turn on power over the cable.
1. 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.
2. Default values for Register bits 27.11:10 are determined by the TxSLEW pins.
3. Default value for Register bit 27.9 is determined by the AMDIX_EN pin.
4. Default value for Register bit 27.8 is determined by the MDIX pin. BGA15 does not support the MDIX
hardware configuration. The BGA15 default = 0.
5. R/W = Read/Write, R = Read Only, LH = Latching High – cleared when read.
6.
216
Datasheet
Document Number: 249241
Revision Number: 007
Revision Date: August 28, 2003