Datasheet
73M1866B/73M1966B Data Sheet DS_1x66B_001
70 Rev. 1.6
Function
Mnemonic
Register
Location
Type Description
ENLVD
0x12[3] WO LeV Detection (OVDET, UVDET, OIDET monitors)
0 = Enable LeV detection. (Default)
1 = Disable LeV detection (used in line-powered mode to save power).
This bit will be 0 when Line Powered Mode is detected (ENLPW is set
in Register 0x02[2]) and set to 1 when an interrupt occurs within the
73M1916. This bit must be reset prior to switching back to Barrier
Powered Mode.
ENNOM 0x12[0] WO Enable Nominal Operation
0 = Speeds up the on and off hook transitions time by increasing the
DC loop bandwidth of the DC transconductance circuit in the
73M1x66B. This should be used for pulse dialing, going on and off
hook, etc. In addition, ENNOM=0 prevents the reset of all bits in
Register 0x12. (Default)
1 = Enter Nominal Operation. Reduces the loop bandwidth of the DC
transconductance circuit. Allows reset of Register 0x12 caused by bits
UVDET, OVDET or OIDET.
ENSHL 0x12[4] WO Enable Shunt Loading
0 = Disable shunt loading. (Default)
1 = Enable shunt loading of the line. Not used for most applications.
IDISPD 0x13[1] WO Discharge and Pulse Dialing
Controls the DC discharge current and how fast the loop turns off.
Affects pulse dialing waveform. Controls the amount of discharge
current during hook switch transitions.
0 = Minimum current. (Default)
1 = Maximum current.
It is recommended to set IDISPD to 1 prior to hook switching
operations.
ILM 0x13[5] WO Current Limit Enable
This control enables or disables loop current limit.
0 = No current limit. (Default)
1 = 42 mA current limit enabled.
ILMON 0x1E[7] R Current Limit Mode On
This status bit is effective only when the ILM bit is set to 1.
0 = Loop current is lower than 42 mA.
1 = Loop current is higher than 42 mA and the current limiting mode is
active.
OFH 0x12[7] WO Off-Hook Enable
This bit controls the state of the Hook signal.
0 = On-Hook. (Default)
1 = Off-Hook.
PLDM 0x13[3] WO Pulse Dialing Mode Enable
Alleviates the strict timing requirements for the Host having to control
ENDC and OFH during pulse dialing. With PLDM = 1, the Host only
has to toggle OFH to perform pulse dialing.
0 = Pulse Dialing Mode is disabled. (Default)
1 = Pulse Dialing Mode is enabled.
RLPNEN 0x16[5] W Receive Low Pass Notch Enable
0 = Billing Tone Receive Low Pass Notch (RLPN) filter bypassed.
(Default)
1 = RLPN Filter Enabled. See RLPNH for notch frequency selection.