TRC101 Datasheet, PDF (18/33 Pages) RF Monolithics, Inc – highly integrated single chip

Frequency Setting Register [POR=A680h]
Bit Bit Bit Bit Bit
Bit
Bit Bit Bit Bit Bit Bit Bit Bit Bit Bit
15 14 13 12 11
10
9
8
7
6
5
4
3
2
1
0
1 0 1 0 Freq11 Freq10 Freq9 Freq8 Freq7 Freq6 Freq5 Freq4 Freq3 Freq2 Freq1 Freq0
The Frequency Setting Register sets the exact frequency within the selected band for transmit or receive.
Each band has a range of frequencies available for channelization or frequency hopping. The selectable
frequencies for each band are:
Frequency Band
300 MHz
400 MHz
800 MHz
900 MHz
Min (MHz)
310.24
430.24
860.48
900.72
Max (MHz)
319.75
439.75
879.51
929.27
Tuning Resolution
2.5 kHz
2.5 kHz
5.0 kHz
7.5 kHz
Bit [15..12] – Command Code: These bits are the command code that is sent serially to the processor
that identifies the bits to be written to the Frequency Setting register.
Bit [11..0] – Frequency Setting: These bits set the center frequency to be used during transmit or
receive. The value of bits[11..0] must be in the decimal range of 96 to 3903. Any value outside of this
range will cause the previous value to be kept and no frequency change will occur. To calculate the
center frequency fc, use Table 9 below and the following equation:
f_c = 10 * B1 * (B0 + f_VAL/4000) MHz
where f_VAL = decimal value of Freq[11..0] = 96<f_VAL<3903.
TABLE 9.
Range B1 B0
315 MHz 1 31
433 MHz 1 43
868 MHz 2 43
916 MHz 3 30
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