CMX808AP4 View Datasheet(PDF) - MX-COM Inc
Part Name
Description
MFG CO.
'CMX808AP4' PDF : 22 Pages View PDF
Family Radio Service CTCSS Processor
16
CMX808A Preliminary Information
5.3 Tx Tone Table
The following table lists the commonly used CTCSS tones and the corresponding values for programming the
CTCSS TX FREQUENCY register $83.
Freq.
(Hz)
67.0
69.3
71.9
74.4
77.0
79.7
82.5
85.4
88.5
91.5
94.8
97.4
100.0
Byte 1
(Hex)
0E
0E
0D
0D
0C
0C
0B
0B
0B
0A
0A
0A
09
Byte 2
(Hex)
93
18
95
20
AF
41
D6
6F
09
AC
4D
07
C4
STANDARD TONES
Freq. Byte 1 Byte 2
(Hz) (Hex) (Hex)
103.5
09
6F
107.2
09
1C
110.9
08
CE
114.8
08
82
118.8
08
38
123.0
07
F1
127.3
07
AC
131.8
07
69
136.5
07
28
141.3
06
E9
146.2
06
AE
151.4
06
73
156.7
06
3B
Freq.
(Hz)
162.2
167.9
173.8
179.9
186.2
192.8
203.5
210.7
218.1
225.7
233.6
241.8
250.3
Byte 1
(Hex)
06
05
05
05
05
05
04
04
04
04
04
04
03
Byte 2
(Hex)
05
D1
9E
6E
3F
11
CD
A3
7A
54
2E
0A
E7
Freq.
(Hz)
62.5
64.7
159.8
Byte 1
(Hex)
0F
0F
06
Byte 2
(Hex)
A0
18
1C
NON-STANDARD TONES
Freq. Byte 1 Byte 2
(Hz) (Hex) (Hex)
183.5
05
52
189.9
05
24
196.6
04
F8
Freq.
(Hz)
199.5
206.5
229.1
Byte 1
(Hex)
04
04
04
Byte 2
(Hex)
E5
BB
43
5.4 Receiver (Decode)
The CTCSS Receiver (Decoder) should first be set up according to the desired characteristics. This entails
setting the CTCSS DECODER BANDWIDTH in the SUB-AUDIO CONTROL register $80, also programming
the center frequencies of the desired tones in the CTCSS RX PROGRAM register $84. (It can hold up to 7
different tones). Any tone can be in any location. During operation when the device is receiving, the tones
are scanned in the sequence of their location, i.e. $0 first and $6 last and once a tone is detected the
remaining tones are not checked. Therefore, if two tones are close enough in frequency for their bandwidths
to overlap then the one in the lowest location will be detected.
The CTCSS IRQ MASK in the SUB-AUDIO CONTROL register $80 should also be set as required.
The CTCSS DECODER ENABLE in the SUB-AUDIO CONTROL register $80 should then be set to "1".
The TONE CLONING register $9C should be set as required.
When the receiver detects a change in its present state an interrupt will be generated. The change that
occurred can be read from Bit 3 of the SUB-AUDIO STATUS register $81 and if a tone is indicated by these
bits then the number of that tone can be read from Bits 2, 1 and 0 of the same register. The interrupt is
cleared by reading the SUB-AUDIO STATUS register.
©1999 MX-COM, Inc.
www.mxcom.com tel: 800 638 5577 336 744 5050 fax: 336 744 5054
Doc. # 20480199.002
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
All trademarks and service marks are held by their respective companies.
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