MT90812 Mitel Networks Corporation, MT90812 Datasheet - Page 67

• Manufacturer Part Number: MT90812
• Description: Integrated Digital Switch (IDX)
• Manufacturer: Mitel Networks Corporation

Advance Information
The SSCA register is used to store the cadence information for Energy Detect block A. Refer to “Supervisory
Signal Detection and Cadence Measurement” on page 47.
The counter is used to time the cadence of the signal. When the signal envelope crosses the energy detect
threshold the counter starts. When the other threshold limit is crossed the P bit is updated, the counter value is
transferred to bits t6-t0, in this SSC register and an interrupt is generated.
The P bit specifies the current envelope position with respect to the high and low thresholds. When P is set this
indicates the signal envelope has crossed above the high threshold otherwise it had crossed below the low
threshold.
The count is stored in 4 msec intervals and ranges from 0 to 508 msec.
For a continuous signal, such as dial tone, where there is no off time, an interrupt is generated when the
counter reaches a maximum count of 508 seconds or 7F
maintaining the same value.
22.15 Energy Detect B - Low Threshold Register (EDBLT)
The EDBLT register is configured as follows:
ET0-ET3 encode the PCM step number while ET4-ET6 encode the PCM chord number.
22.16
The EDBHT register is configured as follows:
ET0-ET3 encode the PCM step number while ET4-ET6 encode the PCM chord number.
Read/Write Address is: 014
Reset Value is: 00
Read/Write Address is: 015
Reset Value is: 00
6-0
6-0
Bit
Bit
7
7
Energy Detect B - High Threshold Register (EDBHT)
High Threshold
Low Threshold
Unused
Unused
Name
Name
H
H
Reserved.
Energy Detect Low Threshold. PCM sign-magnitude format with no sign bit.
Bit 6 = MSB.
Reserved.
Energy Detect High Threshold. PCM sign-magnitude format with no sign bit.
Bit 6 = MSB.
H
H
7
-
7
-
ET6
6
ET6
6
ET5
5
ET5
5
ET4
4
ET4
4
ET3
3
ET3
3
ET2
H
2
. The continuous signal is indicated by the P bit
ET2
Description
Description
2
ET1
1
ET1
1
ET0
0
ET0
0
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