bt8970 Mindspeed Technologies, bt8970 Datasheet - Page 29

• Manufacturer Part Number: bt8970
• Description: Single-chip Hdsl Transceiver
• Manufacturer: Mindspeed Technologies

Bt8970
Single-Chip HDSL Transceiver
value of the slicer error over meter timer interval [meter_low, meter_high; 0x18, 0x19]. At the end of the
measurement interval, the 16 MSBs of the 32-bit accumulator are loaded into the Noise Level Histogram Meter
Register [nlm_low, nlm_high; 0x50, 0x51].
corrective action can be taken. The alarm is based on a second noise level meter. The meter is the same as the
preceding noise level meter except it operates on a dedicated timer, the 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.
100101B
The noise level meter estimates the noise at the input to the slicer. It operates by accumulating the absolute
The SNR alarm provides a rapid indication of impulse noise disturbances and loss of signal so that
Preliminary Information/Conexant Proprietary and Confidential
Conexant
2.0 Functional Description
2.2 Receive Section
2-11