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 (fCTCSS OUT)
Example Limits
fCTCSS OUT
=
=
fXTAL
Hz
fCTCSS OUT
so ‘Q’
=
=
=
=
67Hz
1866
250Hz
500
32 x ‘Q’
“11101001010”
“00111110100”
so ‘Q’
fXTAL
Hz
fCTCSS OUT
so ‘Q’
32 x fCTCSS OUT
(b) NRZ Tx Baud Rate (R NRZ Tx
)
RNRZ Tx
=
=
fXTAL
bits/sec
RNRZ Tx
=
=
67 bits/sec
1866
32 x ‘Q’
so ‘Q’
“11101001010”
“00110100001”
so ‘Q’
fXTAL
32 x RNRZ Tx
RNRZ Tx
=
=
300 bits/sec
417
so ‘Q’
(c) NRZ Rx Baud Rate (R NRZ Rx
)
RNRZ Rx
=
=
fXTAL
bits/sec
RNRZ Rx
=
=
100 bits/sec
114
32 x 11 x ‘Q’
so ‘Q’
“00001110010”
“00000100110”
so ‘Q’
fXTAL
352 x RNRZ Rx
RNRZ Rx
=
=
300 bits/sec
38
so ‘Q’
11
CMLMICRO [ CML MICROCIRCUITS ]
