MT9196 Datasheet, PDF (24/38 Pages) Mitel Networks Corporation – ISO2-CMOS Integrated Digital Phone Circuit (IDPC)

MT9196
Preliminary Information
High Tone Coefficient Register
ADDRESS = 1Bh WRITE/READ VERIFY
H7
H6
H5
H4
H3
H2
H1
H0
Power Reset Value
0000 0000
7
6
5
4
3
2
1
0
The frequency of the high group tone is programmed by writing an 8-bit hexadecimal coefficient at this address according to the
following equation:
Frequency (in Hz) = 7.8125 x COEFF
Where the hexadecimal COEFF is converted into a decimal integer between 0 and 255. Frequency resolution is 7.8125Hz in the range
0 to 1992 Hz.
Anti-Howl Control Register
Enable -
MS1 MS0
ADDRESS = 1Ch WRITE/READ VERIFY
-
Pad2 Pad1 Pad0
Power Reset Value
0X10 X100
Enable
MS1, MS0
Pad2-0
7
6
5
4
3
2
1
0
When high, the anti-howling circuit is enabled. When low, the anti-howling circuit is disabled.
Encode the operational mode of the anti-howling circuit as follows. Details of each mode are found in the functional
description of the anti-howling circuit.
MS1 MS0
Operational Mode
0
0
Transmit Noise Squelch
0
1
Receive Noise Squelch
1
0
Anti-howling for group listening
1
1
Tx/Rx Switched Loss
Three bits encoding the attenuation depth which will be switched into the transmit or receive paths by the anti-howling
circuit. Note that 12 dB is the default value.
Pad2
Pad1
Pad0
Attenuation (dB)
0
0
0
0
0
0
1
3
0
1
0
6
0
1
1
9
1
0
0
12
1
0
1
15
1
1
0
18
1
1
1
21
High Threshold Register
ADDRESS = 1Dh WRITE/READ VERIFY
- THh6 THh5 THh4 THh3 THh2 THh1 THh0
Power Reset Value
X011 0000
THh6-0
7
6
5
4
3
2
1
0
Seven bits encoding the magnitude of the high threshold level. Encoding is in PCM sign-magnitude excluding the sign bit.
THh0 - THh3 encode the step number while THh4 - THh6 encode the chord number. The default setting of 'X011 0000'
encodes chord 3 step 0. The difference between the high and low thresholds defines the hysteresis for anti-howling.
Low Threshold Register
- THI6 THI5
THI4
THI3
THI2
THI1
ADDRESS = 1Eh WRITE/READ VERIFY
THI0
Power Reset Value
X001 0100
THl6-0
7
6
5
4
3
2
1
0
Seven bits encoding the magnitude of the low threshold level. Encoding is in PCM sign-magnitude excluding the sign bit.
THl0 - THl3 encode the step number while THl4 - THl6 encode the chord number. The default setting of 'X001 0100'
encodes chord 1 step 4. The difference between the high and low thresholds defines the hysteresis for anti-howling.
ADDRESSES 1Fh to 3Fh are RESERVED
Note: Bits marked "-" are reserved bits and should be written with logic "0".
7-150