RF60 Datasheet, PDF (58/157 Pages) –

RF60 CRYSTAL-LESS SOC TRANSMITTER v1.0
FC_COUNT counter are stopped and the main FC_COUNT keeps the accumulated value until the fre-
quency counter is disabled or triggered again. The 23 bit FC_COUNT value can be read as a 4 byte long
word, lFcCount, from the XREG register in XDATA. When the counter is counting and FC_BUSY=1, then
reading the FC_COUNT value returns the on the fly changing value of the FC_COUNT counter.
The frequency counter is restartable. If the 1 is written to FC_BUSY while the frequency counter is busy
then the current FC_COUNT result is discarded, main FC_COUNT is reset, and the interval counter is trig-
gered, waiting for the first rising edge of the clk_int clock.
The count interval is chosen with the FC_INTERVAL SFR register. The number of interval count cycles
(count cycles of the low frequency clock) = (2+FC_INTERVAL[0])*(2^FC_INTERVAL[5:1]).
Note: FC_INTERVAL is not allowed to take on numbers higher than 43. If the number is higher than 43,
then the interval counted is forced to 1.
The output of the frequency counter is in the XREG FC_COUNT. The user is recommended to use the Fre-
quency Counter Module Function API to set the following registers.
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