Low Power V.22 bis Modem
CMX868
1.E-03
1.E-04
BER
1.E-05
1.E-06
0
1
2
3
4
5
6
7
Rx Status Register BER reading
Figure 11 Typical Rx BER vs. Average Status Register BER Reading (b2-0)
Programming Register
1.5.10.8
Programming Register : 16-bit write-only.
C-BUS address $E8
This register is used to program the transmit and receive programmed tone pairs by writing appropriate
values to RAM locations within the CMX868. Note that these RAM locations are cleared by Powersave or
Reset.
The Programming Register should only be written to when the Programming Flag bit (b13) of the Status
Register is 1. The act of writing to the Programming Register clears the Programming Flag bit. When the
programming action has been completed (normally within 150ms) the CMX868 will set the bit back to 1.
When programming Transmit or Receive Tone Pairs, do not change the Transmit or Receive Mode
Registers until programming is complete and the Programming Flag bit has returned to 1.
Transmit Tone Pair Programming
4 transmit tone pairs (TA to TD) can be programmed.
The frequency (max 3.4kHz) and level must be entered for each tone to be used.
Single tones are programmed by setting both level and frequency values to zero for one of the pair.
ã 2004 CML Microsystems Plc
32
D/868/9
CMLMICRO [ CML MICROCIRCUITS ]
