Silicon Laboratories Si4700, Руководство по программированию

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AN332
18 Confidential Rev. 0.2
Command 0x31. TX _ TUNE _ POWER
Sets the RF voltage level between 88 dBµV and 115 dBµV in 1 dB units. Power may be set as high as 120 dBµV;
however, voltage accuracy is not guaranteed. A value of 0x00 indicates off. The command also sets the antenna
tuning capacitance. A value of 0 indicates autotuning, and a value of 1–191 indicates a manual override. The CTS
bit (and optional interrupt) is set when it is safe to send the next command. The ERR bit (and optional interrupt) is
set if an invalid argument is sent. Note that only a single interrupt occurs if both the CTS and ERR bits are set. The
optional STC interrupt is set when the command completes. The STCINT bit is set only after the
GET_INT_STATUS command is called. This command may only be sent when in powerup mode. The command
clears the STC bit if it is already set. See Figure 17, “CTS and STC Timing Model,” on page 187 and Table 41,
“Command Timing Parameters for the FM Transmitter,” on page 188.
Command arguments: Four
Response bytes: None
Command
Response
Bit D7 D6 D5 D4 D3 D2 D1 D0
CMD
0 0 1 1 0 0 0 1
ARG1
0 0 0 0 0 0 0 0
ARG2
0 0 0 0 0 0 0 0
ARG3
RFdBµV[7:0]
ARG4
ANTCAP[7:0]
ARG Bit Name Function
1 7:0 Reserved Always write to 0.
2 7:0 Reserved Always write to 0.
3 7:0 RFdBµV[7:0]
Tune Power Byte.
Sets the tune power in dBµV in 1 dB steps. The valid range is from 88–
115 dBµV. Power may be set as high as 120 dBµV; however, voltage accu-
racy is not guaranteed.
4 7:0 ANTCAP[7:0]
Antenna Tuning Capacitor.
This selects the value of the antenna tuning capacitor manually, or automati-
cally if set to zero. The valid range is 0 to 191, which results in a tuning
capacitance of 0.25 pF x ANTCAP.
Bit D7 D6 D5 D4 D3 D2 D1 D0
STATUS CTS ERR X X X RDSINT ASQINT STCINT