ML7406 Datasheet, PDF (68/104 Pages) List of Unclassifed Manufacturers – 868MHz SRD RF transceiver IC

FEDL7406-02
ML7406
(3) IDLE detection mode
IDLE detection mode continues CCA until IDLE detection. IDLE detection CCA will be executed when RX_ON is issued
while CCA_EN(CCA_CTRL: B0 0x39(4)])=0b1, CCA_CPU_EN(CCA_CTRL: B0 0x39(5)])=0b0 and CCA_IDLE_EN
(CCA_CTRL: B0 0x39(6)])=0b1 are set.
Like normal mode, CCA judgement is determined by average ED value and CCA threshold defined by [CCA_LVL: B0
0x37] register. IF average ED value in [ED_RSLT: B0 0x3A] register exceed the CCA threshold value, it is considered as
“BUSY”. And CCA_RSLT[1:0]([CCA_CTRL: B0 0x39(1-0)]) =0b01 is set.
If average ED value is smaller than CCA threshold value and maintains IDLE detection period which is defined by
IDLE_WAIT[9:0] of the [IDLE_WAIT_L: B0 0x3B], [IDLE_WAIT_H: B0 0x3C] registers. it is considered as “IDLE”.
And CCA_RSLT[1:0]([CCA_CTRL:B0 0x39(1-0)]) =0b00 is set. For details operation of CCA_IDLE_WAIT[9:0], please
refer to ”IDLE detection for longer period”.
In IDLE detection mode, only when IDLE is detected, CCA completion interrupt (INT[18] group3 is generated. After
IDLE detection, CCA_EN and CCA_IDLE_EN are reset to 0b0.
Upon clearing CCA completion interrupt, CCA_RSLT[1:0]([CCA_CTRL: B0 0x39(1-0)]) are reset to 0b00.
CCA_RSLT[1:0] should be read before clearing CCA completion interrupt.
If ED value exceeds the value defined by [CCA_IGNORE_LVL: B0 0x36] register, as long as a given ED value is
included in the averaging target of ED value calculation, IDLE judgement is not performed. In this case, if average ED
value is smaller than CCA threshold level, IDLE determination is not performed and CCA_RSLT[1:0] ([CCA_CTRL: B0
0x39(1-0)]) indicates 0b11. CCA operation continues until given ED value is out of averaging target and IDLE is
determined. For details of ED value exceeding [CCA_IGNORE_LVL: B0 0x36] register, please refer to ”IDLE
determination exclusion under strong signal input”.
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