bt8970 Mindspeed Technologies, bt8970 Datasheet - Page 66

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

4.0 Register
0x4A, 0x4B—Noise Level Histogram Meter Register (noise_histogram_low,
noise_histogram_high)
A 2-byte read-only register containing all 16 bits of the unsigned noise-level histogram meter accumulator. This
meter counts the number of high-noise-level conditions which occur during each Meter Timer countdown
interval. A high-noise-level condition is defined as the absolute value of the slicer error signal exceeding
(greater than) the threshold specified in the Noise-level Histogram Threshold Register [0x2A, 2B].
Automatically loaded at the end of each countdown interval, the meter register must be read low byte first,
followed by high byte, unseparated by any other meter access (addresses 0x40 to 0x5F).
0x4C, 0x4D—Bit Error Rate Meter Register (ber_meter_low, ber_meter_high)
A 2-byte read-only register containing all 16 bits of the unsigned bit-error-rate meter accumulator. This meter
counts the number of error-free bits recovered by the detector during each Meter Timer countdown interval. An
error-free bit is defined as a match (equal comparison) of the detector’s slicer/peak detector output and its
scrambler/descrambler output, when operating as a scrambler. When operating as a descrambler, the meter
simply counts the number of logic ones produced by the descrambler. The meter register is automatically loaded
at the end of each countdown interval, and must be read low byte first, followed by high byte, unseparated by
any other meter access (addresses 0x40 to 0x5F).
0x4E—Symbol Histogram Meter Register (symbol_histogram)
A single-byte read-only register containing 8 MSBs of the 16-bit unsigned symbol histogram meter
accumulator. This meter counts the number of plus-one or minus-one symbols (+1, –1) detected during each
Meter Timer countdown interval. No increment occurs when a plus-three or minus-three symbol (+3, –3) is
detected. The meter register is automatically loaded at the end of each countdown interval.
4-22
D[15]
D[15]
D[7]
D[7]
D[7]
7
7
7
D[14]
D[14]
D[6]
D[6]
D[6]
6
6
6
Preliminary Information/Conexant Proprietary and Confidential
D[13]
D[13]
D[5]
D[5]
D[5]
5
5
5
D[12]
D[12]
D[4]
D[4]
D[4]
4
4
4
Conexant
D[11]
D[11]
D[3]
D[3]
D[3]
3
3
3
D[10]
D[10]
D[2]
D[2]
D[2]
2
2
2
Single-Chip HDSL Transceiver
D[1]
D[9]
D[1]
D[9]
D[1]
1
1
1
100101B
D[0]
D[8]
D[0]
D[8]
D[0]
Bt8970
0
0
0