Datasheet

DS_1x66B_001 73M1866B/73M1966B Data Sheet
Rev. 1.6 75
11.12 Line Sensing Control Functions
These registers contain control information to set up and use the 73M1x66B line sensing functions.
Table 40: Line Sensing Control Functions
Function
Mnemonic
Register
Location
Type Description
CIDM 0x15[4] W Caller ID Mode
0 = Disable Caller ID Mode. (Default)
1 = Enables Caller ID Mode by coupling the signal from the RGN/RGP
pins to the PCM DX pins in the appropriate PCM codec format. A 20 dB
gain boost is included in the signal path. The RXBST bit should also be
set to allow the total nominal gain of 40 dB in the Caller ID path. The
normal signal path is disconnected.
RXBST 0x14[3] WO Received Boost
If set to 1, Receive signal is increased by 20 dB. Default is 0. This is
used to amplify signals that are passed through the auxiliary A/D when
On-Hook.
Ring Detection Status Bits
ENRGDT 0x05[0] W Enable Ring Detection Interrupt
This control bit enables the ring detection interrupt.
0 = Ring Detection Interrupt Disabled.
1 = Ring Detection Interrupt Enabled. (Default)
When 73M1922 detects an incoming ring signal, this bit will be set, if
enabled, and reset when read.
RGDT 0x03[0] R Ring or Line Reversal Detection
Voltage greater than the Ring Detect Threshold was detected at
RGP/RGN. This value is latched upon the event and cleared on read.
The threshold is determined by RGTH. This is a maskable interrupt. It is
enabled by the ENRGDT bit.
0 = No Latched Ring or Line Reversal Detection event. (Default)
1 = A Latched Ring or Line Reversal Detection event.
RGMON 0x03[3] R Ringing Monitor
Bit 3 monitors the activity of Ringing for further cadence check by the
host:
0 = Silent
1 = Ringing
This bit is not latched. This status bit is reset when read.
RGTH 0x0E[1:0] W Ring Detect Threshold
Controls the Ring Detect Threshold assuming a 100:1 reduction of Ring
Voltage into the RGP/RGN pins.
RGTH1 RGTH0 Description
0 0 Ring Detect disabled. For ring
detection to occur, these bits
must be programmed to a non-
zero state.
0
1
0.15 Vpk equivalent to ±15 Vpk
at Auxiliary A/D input.
1 0 0.30 Vpk equivalent to ±30 Vpk
at Auxiliary A/D input.
1 1 0.45 Vpk equivalent to ±45 Vpk
at Auxiliary A/D input.