CMX882D6 View Datasheet(PDF) - CML Microsystems Plc
Part Name
Description
MFG CO.
'CMX882D6' PDF : 70 Pages View PDF
FRS Signalling Processor
CMX882
1.6.8 $C1 MODE CONTROL: 16-bit write-only
Bit:
15
14
13
12
11
10
9
8
Enable
Voice
In band signalling:
In-band tone, XTCSS
Generate
Audio Tone
Enable
CTCSS
Enable DCS
Enable DCS
Inverse
0
Bit:
7
6
5
4
3
2
1
0
0
0
0
Enable
2400b/s
Enable
1200b/s
0
Mode Select
Bits 1 and 0 control the overall mode of the CMX882 according to the table below:
Bit 1
0
0
1
1
Bit 0
0
1
0
1
Device Mode
Idle
Receive Mode
Transmit Mode
Reserved - do not use
During transmit, only one signal type may be enabled for each of the sub-audio and voice bands, see
Table 7. During receive the CMX882 will search for all signals enabled in this register and report those
that are successfully decoded. See also Table 2 in section 1.5.3.
In transmit mode the CMX882 begins transmission of a selected signal immediately after it has been
enabled. The host µC must ensure all associated data and control bits have been set to their required
values before enabling the signal in this register.
Bits 4 and 3 control the modem functions of the CMX882 in accordance with the following table:
Bit 4
0
0
1
1
Bit 3
0
1
0
1
Tx - Transmitted signal
None
MSK 1k2b/s
MSK 2k4b/s
Reserved
Rx - Monitored signal(s)
None
MSK 1k2b/s
MSK 2k4b/s
MSK 1k2 & 2k4b/s
In transmit mode data transmission will start or finish (regardless of whether all data has been
transmitted) immediately after the modem control bits are changed. To transmit a second data message
the modem control bits must be set to '0', data bytes for the following message loaded, and the required
bits set to '1'.
Bits 2 and 5 to 8 are reserved - set to '0'.
Bits 11 to 9 determine the sub-audio transmission / reception signalling:
Bit 11 Bit 10 Bit 9 Tx - Transmitted signal:
0
0
0
No Sub-Audio Transmitted
0
0
1
Inverted DCS*
0
1
0
DCS
0
1
1
Do not use
1
0
0
CTCSS
1
0
1
Do not use
1
1
0
Do not use
1
1
1
Do not use
* See Table 4 DCS Modulation Modes.
Rx - Monitored signal(s):
No Sub-audio Monitoring
Inverted DCS*
DCS
DCS + inv DCS*
CTCSS
CTCSS + inv DCS*
CTCSS + DCS
CTCSS + DCS + inv DCS*
Bit 12 enables Audio tone generation (see section 1.6.14). This operates in transmit and receive modes.
In transmit mode this bit will only enable the Audio Generator when no other voice band signals are being
transmitted i.e. bits 14, 13, 4 and 3 set to '0'.
2004 CML Microsystems Plc
40
D/882/7
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