Rockwell SoniCrafter BT8960 - Manual (Page 31)

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2.0 Functional Description
2.2 Receive Section
Bt8960
Single-Chip 2B1Q Transceiver
N8960DSB
2.2.3.1 Digital
Front-End
Prior to the main signal processing, the input signal must be adjusted for any DC
offset. The front-end module also monitors the input signal level, which includes
measuring DC and AC input signal levels, detecting and counting overflows, and
detecting alarms based on the far-end signal level. Figure 2-4 summarizes the fea-
tures of the digital front-end module.
Figure 2-4. Digital Front-End Block Diagram
Echo-Free
Signal
from NEC
DC Offset
from MCI
Accumulator
Result
Register
Far-End
Level Meter
Comparator
Comparator
Far-End
Alarms
High Threshold
from MCI
Low Threshold
from MCI
high_felm
Interrupt
low_felm
Interrupt
Result
Register
Accumulator
DC Level
Meter
Accumulator
Absolute
Result
Register
Signal Level
Meter
ADC Data
r, To EC +
–
Overflow
Detector
Counter
Result
Register
Overflow Monitor
Overflow
Absolute
Value
Value