28960-SWG-001-A_15 Datasheet, PDF (73/105 Pages) M/A-COM Technology Solutions, Inc. – Software Users Guide

Bt8960
Software User’s Guide
Appendix A Command Set Reference
A.2 Status Request Commands
Numeric Value
0x81
Opcode
C Constant (defined in file api.h)
_DC_METER
Option
None
Options
Description
Data
Field
0x00
C Constant (api.h)
A.2.2.1 Bit-pump Response
Signed integer X, –128 ≤ X ≤ 127, relative to the average DC offset per ADC sample. The
measurement scale is such that the actual DC offset in units of ADC LSB is 32X. In case the actual
DC offset is outside the representable range (–4096 to 4095), the nearest representable value will
be used.
A.2.3 Far-End Signal Attenuation
Requests a value of the far-end signal attenuation. This value is based on measuring the average
far-end signal level after echo cancellation.
The result is calibrated to represent the overall signal power attenuation over the cable in dB. It
is also calibrated for an analog gain value of 0 dB, with an absolute gain value as implemented in
Brooktree’s HDSL EVM system. When using a different analog gain value, or an AAGC gain
selection other than 0 dB, the signal attenuation result must be scaled accordingly. For example, if
an analog gain value of 6 dB is used, the actual signal attenuation is 6 dB larger than reported. Note
also that this value depends on the transmitted power at the far-end side, and is calibrated for the
nominal 13.5 dBm value.
Numeric Value
0x82
Opcode
C Constant (defined in file api.h)
_FELM
Option
None
Options
Description
Data
Field
0x00
C Constant (api.h)
A.2.3.1 Bit-pump Response
1-Byte unsigned integer X, 0 ≤ X ≤ 255, indicating the overall signal power attenuation, in units of
0.5 dB. For example, a value of 60 means total cable attenuation of 30 dB.
100251B
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