Baseband Processor For Mixed Mode Land Mobile Radio
CMX880
$C8 (B1.12 to B1.27)
RX SELCALL TONES
Bit:
15
0
14
0
13
0
12
0
11
10
9
8
7
6
5
4
3
2
1
0
Frequency Code
N (defined below)
R (defined below)
The ‘RX SELCALL TONES’ data word is used to program the frequencies of up to 16 tones in the audio band
that will be decoded by the receiver.
Each tone is identified by the ‘Tone Address’ address, which is determined by the order in which the tones are
programmed. ‘Tone Addresses’ range from 0(hex) for the first tone to be programmed, through to F(hex) for the
sixteenth tone to be programmed. If a Selcall tone is not required the ‘RX SELCALL TONES’ word should be set
to zero.
The ‘Frequency Code’ bits of ‘RX SELCALL TONES’ contain the data representing the tone frequency according
to the formula:
In-band Selcall tone formula:
N = (integer) (0.0295 ´ frequency)
R = (0.0295 ´ frequency - N) ´ 6000/frequency
PROGRAMMING REGISTER Block 2
$C8 (B2.1)
TX CTCSS TONE
Bit:
15
1
14
1
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Notone
CTCSS Frequency Code
The ‘CTCSS Tone Frequency’ bits define the tone in accordance with the formula below. If the tone frequency is
programmed with 0, or if the ‘Notone’ bit (bit 13) is set to 1, no CTCSS tone will be transmitted.
When the ‘Notone’ bit is set to 0 and CTCSS transmit mode is enabled, the CTCSS tone is transmitted along
with the signal source defined by the ‘ANALOGUE OUTPUT PATH CONFIGURATION’ register and ‘TX MODE’
register settings.
The frequency of the transmitted CTCSS tone is define according to the formula:
Frequency Code = (integer)(8.191875 ´ frequency)
$C8 (B2.2)
DCS CODE (UPPER)
Bit:
15
0
14
1
13
0
12
11
10
10
9
9
8
7
6
5
4
3
3
2
2
1
1
0
0
DCS
23/24
DCS
Bit 23
DCS Data (bits 22-12)
$C8 (B2.3)
DCS CODE (LOWER)
Bit:
15
0
14
1
13
0
12
0
11
8
7
6
5
4
DCS Data (bits 11-0)
This data defines the DCS code for both transmit and receive modes.
‘DCS 23/24’ (bit 14 of upper word)
0
:
24-bit DCS code
Set ‘DCS Bit 23’ (bit 11 of upper word) to
the value required for the DCS code MSB.
Set ‘DCS Bit 23’ to 0.
1
:
23-bit DCS code
The least significant bit (bit 0) of the DCS code is transmitted first and the most significant bit is transmitted last.
ã 2001 Consumer Microcircuits Limited
62
D/880/1
CMLMICRO [ CML MICROCIRCUITS ]
