Rockwell SoniCrafter BT8960 - Manual (Page 37)

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2.0 Functional Description
2.2 Receive Section
Bt8960
Single-Chip 2B1Q Transceiver
N8960DSB
The SNR alarm provides a rapid indication of impulse noise disturbances and
loss of signal so that corrective action can be taken. The alarm is based on a sec-
ond noise level meter. The meter is the same as the preceding noise level meter
except it operates on a dedicated SNR alarm timer. The absolute value of the
slicer error is accumulated during the timer period. At the end of the measurement
interval, the 16 MSBs of the accumulator are compared against the SNR Alarm
Threshold Register [snr_alarm_th_low, snr_alarm_th_high; 0x34, 0x35]. If the
result is greater than this threshold, an interrupt is set in the irq_source register.
The threshold is set via the microcomputer interface.