AN332
70
Confidential Rev. 0.2
Command 0x24. FM_RDS_STATUS (Si4705/06/21/31/35/37/29/41/49 Only)
Returns RDS information for current channel and reads an entry from the RDS FIFO. RDS information includes
synch status, FIFO status, group data (blocks A, B, C, and D), and block errors corrected. This command clears
the RDSINT interrupt bit when INTACK bit in ARG1 is set and, if MTFIFO is set, the entire RDS receive FIFO is
cleared (FIFO is always cleared during FM_TUNE_FREQ or FM_SEEK_START). The CTS bit (and optional
interrupt) is set when it is safe to send the next command. This command may only be sent when in power up
mode.
Notes:
1.
FM_RDS_STATUS is supported in FMRX comp 2.0 or higher.
2.
MTFIFO is not supported in FMRX comp 2.0.
Command arguments: One
Response bytes: Twelve
Command
Response
Bit
D7
D6
D5
D4
D3
D2
D1
D0
CMD
0
0
1
0
0
1
0
0
ARG1
0
0
0
0
0
STATUSONLY
MTFIFO
INTACK
ARG
Bit
Name
Function
1
2
STATUSONLY
Status Only (Si4706/49 Only)
Determines if data should be removed from the RDS FIFO.
0 = Data in BLOCKA, BLOCKB, BLOCKC, BLOCKD, and BLE contain the oldest
data in the RDS FIFO.
1 = Data in BLOCKA will contain the last valid block A data received for the cur-
rent station. Data in BLOCKB will contain the last valid block B data received for
the current station. Data in BLE will describe the bit errors for the data in
BLOCKA and BLOCKB.
1
1
MTFIFO
Empty FIFO
0 = If FIFO not empty, read and remove oldest FIFO entry.
1 = Clear RDS Receive FIFO.
1
0
INTACK
Interrupt Acknowledge
0 = RDSINT status preserved.
1 = Clears RDSINT.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
STATUS
CTS ERR
X
X
RSQINT
RDSINT
X
STCINT
RESP1
X
X
RDSNEWBLOCKB RDSNEWBLOCKA
X
RDSSYNCFOUND RDSSYNCLOST RDSRECV
RESP2
X
X
X
X
X
GRPLOST
X
RDSSYNC
RESP3
RDSFIFOUSED[7:0]
