3.11.5 sEEPromTrxCalib eepTrxCal
The sEEPromTrxCalib eepTrxCal variable contains the settings for the receiver calibration.
calConf1
The calConf1 variable sets the calibration options during system self-check and calibration. For more details on the functional description, see System Self-Check and Calibration from Related Links.
| Address | Name | Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
|---|---|---|---|---|---|---|---|---|---|
| 0x001C | calConf1 | — | EN_TEMP_MEAS | EN_SRCCAL | EN_FRCCAL | — | — | — | EN_REGREFRESH |
Bit 7: Reserved Bit
This bit is reserved for future use and must be set to ‘0’.
Bit 6: EN_TEMP_MEAS – Enable Temperature Measurement
0 = Temperature measurement disabled
1 = Temperature measurement enabled
Bit 5: EN_SRCCAL – Enable SRC Calibration
0 = Polling cycle/SRC calibration disabled
1 = Polling cycle/SRC calibration enabled
Bit 4: EN_FRCCAL – Enable FRC Calibration
0 = FRC calibration disabled
1 = FRC calibration enabled
Bits 3..1: Reserved Bits
These bits are reserved for future use and must be set to ‘0’.
Bit 0: EN_REGREFRESH – Enable Register Refresh
0 = Register refreshing disabled
1 = Register refreshing enabled
calConf2
The calConf2 variable is used to calibrate the length of the polling cycle to the crystal oscillator frequency.
Address | Name | Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
|---|---|---|---|---|---|---|---|---|---|
0x001D | calConf2 | SRC[7:0] | |||||||
Bits 7..0: SRC[7:0] – SRC Calibration Variable
SRC7 | SRC6 | SRC5 | SRC4 | SRC3 | SRC2 | SRC1 | SRC0 | Function |
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| SRCCAL_VAR = |
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| SRCCAL_VAR = |
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| SRCCAL_VAR = 125 (valid for fXTO = 23.8MHz) |
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| SRCCAL_VAR = 133 (valid for fXTO = 24.305MHz) |
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| SRCCAL_VAR = 163 (valid for fXTO = 26.2MHz) |
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selfChk
The selfChk variable defines the execution period of the self-check function. For more details on the functional description, see PollingMode from Related Links.
Address | Name | Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
|---|---|---|---|---|---|---|---|---|---|
0x001E | selfChk | SC[7:0] | |||||||
Bits 7..0: SC[7:0] – Self-check period 0: No self check
1: Self check every 1*16 polling cycles
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255: Self check every 255*16 polling cycles
tempCal
The tempCal setting contains a 23-byte table for the XTAL temperature deviation. For more details on the functional description, see RF Calibration from Related Links.
Address | Name | Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
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0x001F | tempCal[0] | tempCal_0[7:0] | |||||||
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0x0035 | tempCal[22] | tempCal_22[7:0] | |||||||
The temperature-dependent LO fractional frequency offset caused by the temperature drift of the XTAL is compensated as follows:
The frequency deviation over the crystal temperature must be stored in the EEPROM. There are 23 bytes reserved in the variable tempCal[0:22] for this purpose. This results in a temperature value grid of 8 Kelvin, where tempCal[0] corresponds to -48°C and tempCal[22] to 128°C. Each tempCal byte contains the frequency deviation of the crystal for the defined temperature in ppm in two’s complement representation. The possible compensation range is, thus, -128 ppm to +127 ppm for each temperature value.