
MT90812
vii
1.0
Functional Description....................................................................................................7
2.0
Local TDM Streams .........................................................................................................8
3.0
Expansion Bus.................................................................................................................8
3.1
3.2
TDM Link Mode........................................................................................................................................8
IDX Link Mode..........................................................................................................................................9
4.0
Switching........................................................................................................................10
4.1
Switching Functions ...............................................................................................................................10
4.1.1
Data Transfer from Local TDM Streams to Data Memory.............................................................. 10
4.1.2
Data Transfer from the Expansion Bus to Data Memory................................................................ 10
4.1.3
Connect Memory and Data Memory Structure............................................................................... 10
4.1.4
Switching Output Data from Either Data Memory or Connect Memory.......................................... 10
4.2
Connection Memory...............................................................................................................................10
4.2.1
Connection Memory Usage for Switch Connection or Message Mode .......................................... 11
4.2.2
Connection Memory Select ............................................................................................................ 11
4.2.3
Connect Memory Configurations for Expansion Bus Modes.......................................................... 11
5.0
Address Memory Map ...................................................................................................12
5.1
Memory Page Select..............................................................................................................................12
5.1.1
Addressing Memory Pages in Multiplexed Microport Mode ........................................................... 12
5.1.2
Addressing Memory Pages in Non-Multiplexed Microport Mode.................................................... 12
5.2
Data Memory and Connect Memory ......................................................................................................13
5.2.1
Local Data Memory ........................................................................................................................ 13
5.3
Connection Memory use in Conferencing, Gain Control and specifying Incoming Sources for.............14
5.4
Use of Data Memory Reserved for Expansion Bus Streams .................................................................15
6.0
Conferencing .................................................................................................................18
6.1
6.2
6.3
6.4
6.5
6.6
Channel Attenuation...............................................................................................................................20
Noise Suppression and Channel Inversion............................................................................................20
Tone Insertion ........................................................................................................................................20
Conference Overflow..............................................................................................................................21
Starting a New Conference....................................................................................................................21
Removing a channel from a Conference................................................................................................21
7.0
Gain Control...................................................................................................................22
8.0
Delays Through the MT90812.......................................................................................22
8.1
8.2
8.3
Minimum Delay Mode (CST bit=0).........................................................................................................22
Constant Delay Mode (CST bit=1) .........................................................................................................24
Delays in Conferencing..........................................................................................................................24