Rockwell SoniCrafter BT8960 - Manual (Page 61)

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3.0 Registers
3.1 Conventions
Bt8960
Single-Chip 2B1Q Transceiver
N8960DSB
data_source
[2:0]
Transmitter Mode
000 Isolated pulse. Level selected by isolated_pulse[1:0]. The meter timer must be enabled
and in the continuous mode. The pulse repetition interval is determined by the meter
timer countdown interval.
001 Four-level scrambled detector loopback. Sign and magnitude bits from the receiver
detector are scrambled and looped back to the transmitter. Feedback polynomial deter-
mined by the htur_lfsr control bit.
010 Four-level unscrambled data. Transmits the four-level (2B1Q) sign and magnitude bits
from the channel unit transmit interface without scrambling.
011 Four-level scrambled ones. Transmits a scrambled, constant high logic level as a four-
level (2B1Q) signal. Feedback polynomial determined by the htur_lfsr control bit.
100 Reserved.
101 Four-level scrambled data. Scrambles and transmits the four-level (2B1Q) sign and mag-
nitude bits from the channel unit transmit interface. Feedback polynomial determined by
the htur_lfsr control bit.
110 Two-level unscrambled data. Constantly forces the magnitude bit from the channel unit
transmit interface to a logic zero and transmits the resulting two-level signal (as deter-
mined by the sign bit) without scrambling. Valid output levels limited to +3, –3.
111 Two-level scrambled ones. Transmits a scrambled, constant high-logic level as a two-
level signal. Feedback polynomial determined by the htur_lfsr control bit. Scrambler is
run at the symbol rate (half-bit rate) to produce the sign bit of the transmitted signal
while the magnitude bit is sourced with a constant logic zero. Valid output levels limited
to +3, –3.