MT90812 Datasheet, PDF (54/105 Pages) Mitel Networks Corporation – Integrated Digital Switch (IDX)

MT90812
Advance Information
21.0 Connection Memory Bits
Locations in the Connection Memory are associated with the local TDM output streams and the Expansion Bus
streams. It also determines whether individual output channels are in Message Mode, allows individual output
channel to go into a high-impedance state and specifies the gain control for the outgoing channels. Refer to
Section 5.2, “Data Memory and Connect Memory” for further description.
21.1 Connection Memory High
76543210
G4
G3
G2
G1
G0
MSG/ CST/ OE/
INV NS1 NS0
Bit
Name
Description
7-3
Channel
Defines gain from +3 to -27 dB in steps of 1dB, as well as - ∞ dB for the outgoing
Attenuation
channel
G4,G3, G2, G1,
G0
0000 = +3 dB
0001 = +2 dB
10000 = -13dB
10001 = -14dB
0010 = +1 dB
10010 = -15dB
0011 = 0 dB
10011 = -16dB
0100 = -1 dB
10100 = -17dB
0101 = -2 dB
10101 = -18 dB
0110 = -3 dB
10110 = -19 dB
0111 = -4 dB
10111 = -20 dB
1000 = -5 dB
11000 = -21 dB
1001 = -6 dB
11001 = -22 dB
1010 = -7 dB
11010 = -23 dB
1011 = -8 dB
11011 = -24 dB
1100 = -9 dB
11100 = -25 dB
1101 = -10 dB
11101 = -26 dB
1110 = -11 dB
11110 = -27 dB
1111 = -12 dB
11111 = - ∞ dB
2 Message Channel/ When 1, the contents of the corresponding location in Connection Memory Low are
Conference
output on the location’s channel. When 0, the contents of the corresponding
Inversion Bit
location in Connection Memory Low act as an address for the Data Memory and so
determine the source of the connection to the location’s channel and stream.
Conference Inversion Bit: (For Conference address locations 60-6E) The inversion
bit allows for every other channel in a conference to be inverted. This reduces noise
due to reflections and line impedance mismatch.
1
CST
This bit is used to select minimum(low) or constant(high) delay, on a per channel
(address
basis.
locations other
than 60-6E)
0
Output Enable If the ODE pin is high and bit 5 of the Control Register is 0, then this bit enables the
(address
output driver for the location’s channel and stream. This allows individual channels
locations other on individual streams to be made high-impedance, allowing switching matrices to
than 60-6E)
be constructed. A 1 enables the driver and a 0 disables it.
1-0
NS1-NS0
Channel Noise Suppression
(for Conference 00 = no noise suppression
address locations 01 = 9/4096 (A-Law), 9/8159 (u-Law)
60-6E)
10 = 16/4096 (A-Law), 16/8159 (u-Law)
11 = 32/4096 (A-Law), 32/8159 (u-Law)
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