
AN543
Rev. 0.9
193
Property 0x4003 FM_RDS_CONFIDENCE (Si4751/53/55/57 Only)
The FM_RDS_CONFIDENCE property sets the required receiver confidence level for each RDS block prior to
demodulation. A higher confidence requirement will result in more block errors (higher percentage of blocks with
BLE = 3) but reduces the chance of decoder errors (lower percentage of blocks that contain incorrect information
despite having BLE<3). Higher confidence requirements may result in a decrease in the frequency with which RDS
data is stored in the FIFO. Higher block error rate will affect RDS sensitivity tests. 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 when in the
powerup mode.
Default: 0x1111
FM_RDS_CONFIDENCE
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
CONFIDENCEA[3:0]
CONFIDENCEB[3:0]
CONFIDENCEC[3:0]
CONFIDENCED[3:0]
0x1
0x1
0x1
0x1
Bit
Name
Function
15:12
CONFIDENCEA[3:0]
Sets the decoder error rate threshold for BLOCK A.
0 = Reserved.
1 = Lowest confidence required. A valid and usable confidence threshold.
2–14 = Medium confidence required. High value may result in all blocks
being marked as uncorrectable.
15 = Highest confidence required. This setting may result in all blocks being
marked as uncorrectable.
11:8
CONFIDENCEB[3:0]
Sets the decoder error rate threshold for BLOCK B.
0 = Reserved.
1 = Lowest confidence required. A valid and usable confidence threshold.
2–14 = Medium confidence required. High value may result in all blocks
being marked as uncorrectable.
15 = Highest confidence required. This setting may result in all blocks being
marked as uncorrectable.
7:4
CONFIDENCEC[3:0]
Sets the decoder error rate threshold for BLOCK C.
0 = Reserved.
1 = Lowest confidence required. A valid and usable confidence threshold.
2–14 = Medium confidence required. High value may result in all blocks
being marked as uncorrectable.
15 = Highest confidence required. This setting may result in all blocks being
marked as uncorrectable.
3:0
CONFIDENCED[3:0]
Sets the decoder error rate threshold for BLOCK D.
0 = Reserved.
1 = Lowest confidence required. A valid and usable confidence threshold.
2–14 = Medium confidence required. High value may result in all blocks
being marked as uncorrectable.
15 = Highest confidence required. This setting may result in all blocks being
marked as uncorrectable.