xe1202 ETC-unknow, xe1202 Datasheet - Page 10

• Manufacturer Part Number: xe1202
• Description: Low-power, Integrated Uhf Transceiver
• Manufacturer: ETC-unknow

The threshold f
As an example, for a bit rate of 4.8 kb/s and with FERR = 0.5, f
This FEI function works properly only if the input signal is the preamble defined under the Receiver section above
and if the frequency error to be detected is lower than 20 kHz.
The time diagram of an FEI measurement is quite similar to the one of an RSSI measurement, and is given in the
figure below. When the FEI is activated the frequency error is periodically measured and the result is stored in the
register “DataOut_FEI” at each rising edge of DATAIN. TS_FE is the wake-up time required after the function has
been activated to get a valid result.
4.1.4.2
To activate the FEI function, the bit “RTParam_FEI” must be set to “1”. When activated by the rising edge of
DATAIN, the function provides an 8-bits status stored in register “DataOut_FEI”. The timing diagram of this FEI
measurement is described in the in figure below. The FEI function is activated at the rising edge of the EN signal
when the RTParam_FEI bit is set to “1”. Then, an internal FEI counter is activated at the rising edge of DATAIN.
After duration TS_FE (see Electrical Specifications), the counter is stopped and its content is stored in the register
DataOut_FEI. The maximum delay between the rising edge of DATAIN and the first clock on the internal FEI
counter is 1/(16*BR), where BR is the bit rate.
10
“RTParam_Fsel” = 0
ERR
= FERR * BR, where BR is the bit rate and FERR is a ratio given in the electrical specifications.
RTParam_FEI
RTParam_FEI
DataOut_FEI
DataOut_FEI
fei_out
fei_out
datain
datain
en
en
Figure 2 FEI measurement time diagram, RTParam_Fsel = 1
TS_FE
TS_FE
XX
XX
XX
XX
VAL1
VAL1
ERR
VAL2
VAL2
is 2.4 kHz.
VAL3
VAL3
VAL2
VAL2
VAL4
VAL4
VAL4
VAL4
Data Sheet
XE1202
XX
XX
D0211-105