CMX878D6 View Datasheet(PDF) - CML Microsystems Plc
Part Name
Description
MFG CO.
'CMX878D6' PDF : 63 Pages View PDF
Line Powered Modem plus DAA
CMX878
Bit 14 going to 1 can also produce an IRQ if the appropriate mask bits have been set – although this is
only possible in the case where the Regulated Supply has not been de-powered since the setting of the
mask bits.
The microcontroller is therefore made aware of the Line/Wakeup Event by being powered up or with an
interrupt. Following this powerup/IRQ, the microcontroller should read the Status Register to clear any
interrupt. It should then read the Line/Wakeup Event Register to determine which Line/Wakeup Event
had occurred.
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)
1.5.12.14
Programming Register
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 CMX878. 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 150µs) the CMX878 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.
© 2002 Consumer Microcircuits Limited
44
D/878/2
Share Link: 
