DS3181/DS3182/DS3183/DS3184
233
Register Name:
PORT.CR2
Register Description:
Port Control Register 2
Register Address:
(0,2,4,6)42h
Bit #
15
14
13
12
11
10
9
8
Name
TLEN
TTS
RMON
TLBO
RCDV8
LM2
LM1
LM0
Default
0
Bit #
7
6
5
4
3
2
1
0
Name
RCDIS
PMCPE
FM5
FM4
FM3
FM2
FM1
FM0
Default
0
Bit 15: Transmit Line IO Signal Enable (TLEN). This bit is used to enable to transmit line interface output pins
TLCLKn, TPOSn/TDATn and TNEGn.
0 = Disable, force outputs low
1 = Enable normal operation
Bit 14: Transmit LIU Tri-State (TTS) This bit is used to tri-state the transmit TXPn and TXNn pins. The LIU is still
powered up when the pins are tri-stated. It has no effect when the LIU is disabled and powered down.
0 = TXPn and TXNn driven
1 = TXPn and TXNn tri-stated
Bit 13: Receive LIU Monitor Mode (RMON) This bit is used to enable the receive LIU monitor mode pre-amplifier.
Enabling the pre-amplifier adds about 20 dB of linear amplification for use in monitor applications where the signal
has been reduced 20 dB using resistive attenuator circuits.
0 = Disable the 20 dB pre-amp
1 = Enable the 20 dB pre-amp
Bit 12: Transmit LIU LBO (TLBO) This bit is used enable the transmit LBO circuit which causes the transmit
signal to have a wave shape that approximates about 225 feet of cable. This is used to reduce near end crosstalk
when the cable lengths are short. This signal is only valid in DS3 and STS-1 LIU modes.
0 = TXPn and TXNn have full amplitude signals
1 = TXPn and TXNn signals approximate 225 feet of cable
Bit 11: Receive ATM Cell Delineation Verify 8 Enable (RCDV8). This bit determines the number of good cells
required for the ATM cell delineator state machine to transition from the “Verify” state to the “Update” state. This
setting also determines how many valid cells required to clear the OCD status bit.
0 = Six valid ATM cells are required (typical for framed cells)
1 = Eight valid ATM cells are required (typical for unframed cells)
Bits 10 to 8: Port Interface Mode (LM[2:0]). The LM[2:0] bits select main port interface operational modes. The
Bit 7: Receive Cell Delineator Disable (RCDIS). This bit determines if the ATM cell delineator in the ATM cell
processor is active in PLCP modes. This ATM cell delineator in the ATM cell processor is always active in non-
PLCP ATM cell modes.
0 = ATM cell delineation is determined in the ATM cell processor
1 = ATM cell delineation is determined in the PLCP framer
Note: RCDIS = 1 is not a recommended mode.
Bit 6: POS-PHY Mode Cell Processor Enable (PMCPE). This bit determines the associated transmit and receive
port interface processing (cell/packet) to be performed in the POS-PHY mode. It is only active in POS-PHY mode
when PLCP is not enabled. When PLCP is enabled in POS-PHY mode, cell processing is performed.
0 = Packet processing will be performed
1 = Cell processing will be performed
Bits 5 to 0: Framing mode (FM[5:0]). The FM[5:0] bits select main framing operational modes. Default: DS3 C-bit.