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A)
Additional Note of noise addition for high frequency signal
Noise Detection monitors noise level near 34 kHz in FSK demodulation signal. Therefore, both "Signal
Detection" and "No Signal Detection" in Noise Detection function may be false because of the noise
reduction caused by high frequency signal. To avoid this, TC32306FTG has an additional function to
improve detection accuracy.
This function improves detection accuracy to add a constant value to detected noise level when input
signal is high frequency. Set register:h'19[D0]Add_Hdet_en = "1" and this is valid. This function
operates independently following register settings, Noise Detection (h'0F[D5]]Ndet_en), IF Detection
(h'10[D0]Sel_Det) and High Frequency Detector (h'0F[D4]Hdet_en).
Table 6-23 Settings of Noise Addition for High Frequency Signal
h'0F[D5]
h'19[D0]
Ndet_en
Add_Hdet_en
0
0
0
1
1
0
1
1
Notice:
-
In the settings of register: Ndet_en (h'0F[D5] = "0") and register: Add_Hdet_en (h'19[D0] = "1"),
when High Frequency Signal is occupied in the half of RSSI / Noise detection interval set by
register:[D7:D6]Ntime1..0, the register of Noise Signal Level Monitor (h'23[D7:D0]DNDET7..0)
outputs "d'40". When High Frequency Signal is occupied in the full of RSSI / Noise detection
interval, the register of Noise Signal Level Monitor (h'23[D7:D0]DNDET7..0) outputs "d'81".
-
Noise Addition for High Frequency Signal can be valid in Pulse Count Detection and Delay
Detection.
-
Noise Addition for High Frequency Signal can be valid even if High Frequency Detector is not
valid in Delay Detection.
B)
Additional Note of Preamble Detection
The function of Preamble Detection checks signal by counting the number of clocks between the rising
edges, or between the falling edge and the rising edge of output signal from Data COMP circuit. If the
number of clocks is counted within the set value +/- error margin (h'18[D6:D0]), this signal is
recognized as Preamble signal. The clock frequency is twice by the internal clock using in Bit Rate
Filter. About internal clock frequency, see Table 6-25.
Notice: 1
-
When the function of Preamble Detection checks signal by counting the number of clocks between
the rising edges (h'1A[D2] = "0"), the number of count is as same as the setting value of register:
Pre_Time8..0.
-
When the function of Preamble Detection checks signal by counting the number of clocks between
the rising edge and the falling edge (h'1A[D2] = "1"), the number of count is half of the setting
value of register: Pre_Time8..0. If the value of register: Pre_Time8..0 is odd, half of this setting
value is rounded down to the integer.
-
Both signal counting the number of clocks between the rising edges (h'1A[D2] = "0") and between
the rising edge and falling edge (h'1A[D2] = "1"), error margin is as same as the setting value of
register: Err_Margin6..0.
Way of setting:
-
Setting value: Pre_Time8..0(h'18[D7],h'17[D7:D0])
-
Error margin: Err_Margin6..0(h'18[D6:D0])
-
The number of clocks: Pre_Time8..0 = (2 x fbc)/fp
-
fp: preamble signal cycle frequency
Both Noise Detection and Noise Addtion for High Frequency Signal are not valid.
Noise Addtion for High Frequency Signal is valid.
Noise Detection is not valid.
"No Signal Detection" is operated, but "Signal Detection" is not operated.
Noise Detection is valid.
Noise Addtion for High Frequency Signal is not valid.
Both Noise Detection and Noise Addtion for High Frequency Signal are valid.
25
Function Status
TC32306FTG
2015-10-01
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