AN543
Rev. 0.9
89
Property 0x0710 FM_AGC_OVERRIDE
The FM_AGC_OVERRIDE property overrides the AGC setting by disabling the AGC and forcing the gain to be
maximum. 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:
In Si475x-A30 only, property FM_AGC_PD_CONFIG should be set to 0x0000 when overriding the AGC with the
FM_AGC_OVERRIDE property. Doing so removes the automatic AGC from peak detector control. Failure to set
FM_AGC_PD_CONFIG when using FM_AGC_OVERRIDE could lead to a conflict which locks the tuner following an
FM_TUNE_FREQ command.
Default: 0x0000
Property 0x071B FM_AGC_RSSI_OFFSET
The FM_AGC_RSSI_OFFSET property sets the value of the offset applied to the RSSI value in order to account
for the front-end gain/loss due to the AGC. 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.
Si475x-A10 and before: This property is not available
Si475x-A20 and later, Default: 0
Units: dB
FM_AGC_OVERRIDE
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0x000
AGC_OVERRIDE[5:0]
0x000
0x000
Bit
Name
Function
15:6
Reserved
Always write 0.
5:0
AGC_OVERRIDE[5:0]
AGC_OVERRIDE selects whether the AGC is
enabled or disabled.
0 = AGC is enabled.
0x3F = AGC is disabled and set to maximum
gain.
FM_AGC_RSSI_OFFSET
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
OFFSET[7:0]
RSVD[7:0]
0x00
0x00
Bit
Name
Function
15:8
OFFSET[7:0]
Sets the RSSI offset value to take into account front-end gain/loss.
Default is 0.
Range is –128 to 127.
7:0
Reserved
Always write 0.
