Datasheet

70
4341H–MP3–10/07
AT8xC51SND2C/MP3B
Table 13-6. MP3STA Register
MP3STA (S:C8h Read Only) – MP3 Decoder Status Register
Reset Value = 0000 0001b
Table 13-7. MP3DAT Register
MP3DAT (S:ACh) – MP3 Data Register
Reset Value = 0000 0000b
7 6 5 4 3 2 1 0
MPANC MPREQ ERRLAY ERRSYN ERRCRC MPFS1 MPFS0 MPVER
Bit Number
Bit
Mnemonic Description
7 MPANC
Ancillary Data Available Flag
Set by hardware as soon as one ancillary data is available (buffer not empty).
Cleared by hardware when no more ancillary data is available (buffer empty).
6 MPREQ
MP3 Data Request Flag
Set by hardware when MP3 decoder request data.
Cleared when reading MP3STA.
5 ERRLAY
Invalid Layer Error Flag
Set by hardware when an invalid layer is encountered.
Cleared when reading MP3STA.
4 ERRSYN
Frame Synchronization Error Flag
Set by hardware when no synchronization pattern is encountered in a frame.
Cleared when reading MP3STA.
3 ERRCRC
CRC Error Flag
Set by hardware when a frame handling CRC is corrupted.
Cleared when reading MP3STA.
2 - 1 MPFS1:0
Frequency Sampling Bits
Refer to Table 13-4 for bits description.
0 MPVER
MPEG Version Bit
Set by the MP3 decoder when the loaded frame is a MPEG I frame.
Cleared by the MP3 decoder when the loaded frame is a MPEG II frame.
7 6 5 4 3 2 1 0
MPD7 MPD6 MPD5 MPD4 MPD3 MPD2 MPD1 MPD0
Bit Number
Bit
Mnemonic Description
7 - 0 MPD7:0
Input Stream Data Buffer
8-bit MP3 stream data input buffer.