Datasheet

73M1866B/73M1966B Data Sheet DS_1x66B_001
44 Rev. 1.6
7.6 Call Progress Monitor
For the purpose of monitoring activities on the line, a Call Progress Monitor is provided in the 73M1x66B.
This audio output contains both transmit and receive data with configurable levels.
7.7 16 kHz Operation of Call Progress Monitor
After switching from 8 kHz sampling rate to 16 kHz sampling rate, the SLEEP bit must be enabled then
disabled if the Call Progress Monitor function is used. After cycling the SLEEP bit, the Line-Side Device
registers (Registers 0x12 to 0x18) must be reconfigured.
7.8 Device Reset
For a correct reset of the 73M1x66B, the RST signal must be asserted for a minimum period of 1 ms.
PCLK must be active for a minimum of 8 clock cycles before the RST signal can be de-asserted. The
PLL locks to the PCLK after 20 PCM frames as defined by the occurrence of the Frame Sync Signal (FS).
This gives a minimum period of 3.5 ms from the assertion of RST until the PLL is locked and normal
operations may occur, including access to all device registers and the transmission and reception of PCM
data samples. If PCLK changes frequency, then the PLL will lose lock so a stable clock must be used
during this reset period. If a PCLK frequency change is required after the reset, the user should
implement the procedure described for PCODE (Register 0x23 bits 2 to 5).
Function
Mnemonic
Register
Location
Type Description
CMRXG 0x10[1:0]
W Receive Path Gain Setting
00 0 dB (for full swing, AOUT=1.08 Vpk) (Default)
01 -6 dB
10
-12 dB
11
MUTE
CMTXG 0x10[3:2]
W Transmit Path Gain Setting
00 0 dB (for full swing, AOUT=1.08 Vpk) (Default)
01 -6 dB
10 -12 dB
11 MUTE
CMVSEL 0x10[4] W Call Progress Monitor Voltage Reference Select
Quiescent DC voltage select at AOUT.
0 = 1.5 Vdc. (Default)
1 = VCC/2 Vdc.