AN543
Rev. 0.9
131
Property 0x2204 FM_CHBW_SQ_NARROWING_TIME (Si4754/55/56/57 Only)
The FM_CHBW_SQ_NARROWING_TIME property sets the Channel Filter Bandwidth narrowing time based on
RSSI/STRONGDEV (for Si475x-A20 and later) or RSSI/SNR (for Si475x-A10), as selected with through property
0x1306, FM_ACF_CONTROL. For Si475x-A20 and later, this engine is only enabled when RSSI is below the
FM_CHBW_WEAKSIG_THR (property 0x220F). The CTS bit (and optional interrupt) is set when it is safe to send
the next command. This property may only be set or read in powerup mode.
Note:
RSSI/SNR can be used to control this engine for Si475x-A10. RSSI/STRONGDEV can be used to control this engine for
Si475x-A20 and later.
Default: 2048
Si475x-A10, Units: ms
Si475x-A20, Units: 0.2 ms
Si475x-A30 and later, Units: 0.4 ms
FM_CHBW_SQ_NARROWING_TIME
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
NARROWING_TIME[15:0]
0x0800
Bit
Name
Function
15:0
NARROWING_TIME[15:0]
Sets the RSSI based Channel Filter Bandwidth narrowing
time.
Default is 2048.
Range is 1–32767.