Controlling Protocol ......
“Write to CTCSS Tx Frequency/NRZ Baud Rate Register” ......
Command Word ‘Q’
With reference to Figure 7, Bits 0 to 10 are used to produce the data word ‘Q’ which sets one of the parameters described
below. As can be seen, command word ‘Q’ could be used to produce a word whose value would produce a parameter outside
that specified, care should be taken not to do this. Examples for limits of ‘Q’ in each operational configuration are included. ‘Q’
= 0 is not valid in the following calculations. Bit 11 is not used and must be set to logic “0”.
(
a)
CTCSS Tx Tone Frequency (f
CTCSS OUT
)
Example Limits
f
CTCSS OUT
=
f
XTAL
32 x ‘Q’
Hz
f
CTCSS OUT
so ‘Q’
=
=
=
=
67Hz
1866
250Hz
500
“00111110100”
“11101001010”
so ‘Q’
=
f
XTAL
32 x f
CTCSS OUT
Hz
f
CTCSS OUT
so ‘Q’
(b) NRZ Tx Baud Rate (R
NRZ Tx
)
R
NRZ Tx
=
f
XTAL
32 x ‘Q’
bits/sec
R
NRZ Tx
so ‘Q’
=
=
67 bits/sec
1866
“11101001010”
so ‘Q’
=
f
XTAL
32 x R
NRZ Tx
R
NRZ Tx
so ‘Q’
=
=
300 bits/sec
417
“00110100001”
(c) NRZ Rx Baud Rate (R
NRZ Rx
)
R
NRZ Rx
=
f
XTAL
32 x 11 x ‘Q’
bits/sec
R
NRZ Rx
so ‘Q’
=
=
100 bits/sec
114
“00001110010”
so ‘Q’
=
f
XTAL
352 x R
NRZ Rx
R
NRZ Rx
so ‘Q’
=
=
300 bits/sec
38
“00000100110”
11
CMLMICRO [ CML MICROCIRCUITS ]
