
Sub 1 GHz Transceiver Architecture Description
MKW01xxRM Reference Manual, Rev. 3, 04/2016
Freescale Semiconductor, Inc.
5-21
5.7.13
Frequency Error Indicator (FEI)
This function provides information about the frequency error of the local oscillator (LO) compared with
the carrier frequency of a modulated signal at the input of the receiver. When the FEI block is launched,
the frequency error is measured and the signed result is loaded in
FeiValue
in
RegFei
, in 2’s complement
format. The time required for an FEI evaluation is 4 times the bit period.
To ensure a proper behavior of the FEI:
•
The operation must be done during the reception of preamble
•
The sum of the frequency offset and the 20 dB signal bandwidth must be lower than the base band
filter bandwidth
The 20 dB bandwidth of the signal can be evaluated as follows (double-side bandwidth):
The frequency error, in Hz, can be calculated with the following formula:
Figure 5-10. FEI Process
BW
20dB
2
F
DEV
BR
2
--------
+
=
FEI
F
STEP
FeiValue
=
SX1231 in Rx mode
Preamble-modulated input signal
Signal level > Sensitivity
Set
FeiStart
= 1
FeiDone
= 1
No
Yes
Read
FeiValue
MKW01
Содержание MKW01Z128
Страница 7: ...MKW01xxRM Reference Manual Rev 3 04 2016 viii Freescale Semiconductor Inc...
Страница 11: ...MKW01xxRM Reference Manual Rev 3 04 2016 xii Freescale Semiconductor Inc...
Страница 31: ...MKW01Z128 Pins and Connections MKW01xxRM Reference Manual Rev 3 04 2016 2 8 Freescale Semiconductor Inc...
Страница 129: ...MKW01Z128 Transceiver MCU SPI Interface MKW01xxRM Reference Manual Rev 3 04 2016 8 6 Freescale Semiconductor Inc...
Страница 130: ...MKW01xxRM Reference Manual Rev 3 04 2016 Freescale Semiconductor Inc A 1 Appendix A MKW01Z128 MCU Reference Manual...
Страница 131: ...MKW01Z128 MCU Reference Manual MKW01xxRM Reference Manual Rev 3 04 2016 A 2 Freescale Semiconductor Inc...
Страница 133: ...MKW01Z128 MCU Reference Manual Rev 3 04 2016 2 Freescale Semiconductor Inc...
Страница 221: ...Private Peripheral Bus PPB memory map MKW01Z128 MCU Reference Manual Rev 3 04 2016 90 Freescale Semiconductor Inc...
Страница 233: ...Module clocks MKW01Z128 MCU Reference Manual Rev 3 04 2016 102 Freescale Semiconductor Inc...
Страница 255: ...Module operation in low power modes MKW01Z128 MCU Reference Manual Rev 3 04 2016 124 Freescale Semiconductor Inc...
Страница 279: ...Functional description MKW01Z128 MCU Reference Manual Rev 3 04 2016 148 Freescale Semiconductor Inc...
Страница 305: ...Functional description MKW01Z128 MCU Reference Manual Rev 3 04 2016 174 Freescale Semiconductor Inc...
Страница 325: ...Functional description MKW01Z128 MCU Reference Manual Rev 3 04 2016 194 Freescale Semiconductor Inc...
Страница 379: ...Application information MKW01Z128 MCU Reference Manual Rev 3 04 2016 248 Freescale Semiconductor Inc...
Страница 387: ...Memory map register descriptions MKW01Z128 MCU Reference Manual Rev 3 04 2016 256 Freescale Semiconductor Inc...
Страница 465: ...Functional Description MKW01Z128 MCU Reference Manual Rev 3 04 2016 334 Freescale Semiconductor Inc...
Страница 501: ...Initialization Application information MKW01Z128 MCU Reference Manual Rev 3 04 2016 370 Freescale Semiconductor Inc...
Страница 513: ...Interrupts MKW01Z128 MCU Reference Manual Rev 3 04 2016 382 Freescale Semiconductor Inc...
Страница 517: ...Functional description MKW01Z128 MCU Reference Manual Rev 3 04 2016 386 Freescale Semiconductor Inc...
Страница 611: ...Application information MKW01Z128 MCU Reference Manual Rev 3 04 2016 480 Freescale Semiconductor Inc...
Страница 633: ...CMP Trigger Mode MKW01Z128 MCU Reference Manual Rev 3 04 2016 502 Freescale Semiconductor Inc...
Страница 643: ...Functional description MKW01Z128 MCU Reference Manual Rev 3 04 2016 512 Freescale Semiconductor Inc...
Страница 671: ...Functional description MKW01Z128 MCU Reference Manual Rev 3 04 2016 540 Freescale Semiconductor Inc...
Страница 803: ...Functional description MKW01Z128 MCU Reference Manual Rev 3 04 2016 672 Freescale Semiconductor Inc...
Страница 843: ...Functional description MKW01Z128 MCU Reference Manual Rev 3 04 2016 712 Freescale Semiconductor Inc...
Страница 877: ...Initialization application information MKW01Z128 MCU Reference Manual Rev 3 04 2016 746 Freescale Semiconductor Inc...