MAS3587F Micronas, MAS3587F Datasheet - Page 40

• Manufacturer Part Number: MAS3587F
• Description: MPEG Layer 3 Audio Encoder/Decoder
• Manufacturer: Micronas

MAS 3587F
Table 3–8: D0 Status Memory Cells
3.3.4. Ancillary Data
The memory fields D0:FD5...D0:ff1 contain the ancil-
lary data. It is organized in 28 words of 16 bit each.
The last ancillary bit of a frame is placed at bit 0 in
D0:FD5. The position of the first ancillary data bit
received can be located via the content of NumberO-
fAncillaryBits because
of memory words are used.
Example:
First get the content of ’NumberOfAncillaryBits’
<DW 68 c4 00 00 01 0f d4>
<DW 69 <DR
40
Memory
Address
D0:FD2
(continued)
D0:FD3
D0:FD4
D0:FD5
...
D0:FF1
int[(NumberOfAncillaryBits-1)/16] + 1
Function
MPEG Header Information, continued
bit[1:0]
This memory cell contains the 16 LSBs of the MPEG header. It will be set
directly after synchronizing to the bit stream.
MPEG CRC Error Counter
The counter will be increased by each CRC error detected in the MPEG bis-
stream. It will not be reset when losing the synchronization.
Number of Bits in Ancillary Data
Number of valid ancillary bits in the current MPEG frame.
Ancillary Data
(see Section 3.3.4. on page 40).
dd
dd>
Emphasis, indicates the type of emphasis
00
01
10
11
none
50/15 s
reserved
CCITT J.17
Assume that the MAS 3587F has received 19 ancillary
data bits. Therefore, it is necessary to read two 16-bit
words:
<DW 68 c4 00
<DW 69 <DR
The first bit received from the MPEG source is at posi-
tion 2 of D0:FD6; the last bit received is at the LSB of
D0:fd5.
00 02 0f d5>
dd dd
dd
dd>
Decoder
Decoder
Decoder
Short Read from D0
read 2 words starting at D0:fd5
receive the 2 16-bit words
ADVANCE INFORMATION
Name
MPEGStatus2
CRCErrorCount
NumberOfAncillary-
Bits
AncillaryData
Micronas