CM6500B Datasheet, PDF (25/36 Pages) C-Media Electronics – USB Audio Sound Chip

CM6500 / CM6500B
USB Audio Sound Chip
 Audio format : linear 16 bit default.
 Allowed sampling frequencies (Fs) of the audio:
 44.1kHz from CD
 48 kHz from DAT
 32 kHz from DSR
 One way communication: from a transmitter to a receiver.
 Control information:
 V (validity) bit : indicates if audio sample is valid.
 U (user) bit : user free coding i.e. running time song, track number.
 C (channel status) bit : emphasis, sampling rate and copy permit.
 P (parity) bit : error detection bit to check for good reception.
 Coding format: biphase mark except the headers (preambles), for sync purposes.
 Bandwidth occupation : 100kHz up to 6Mhz (no DC!)
 Signal bitrate is 2.8Mhz (Fs=44.1kHz), 2Mhz (Fs=32kHz) and 3.1Mhz (Fs=48kHz).
Clock
Data Signal
10011010010
Biphase Mark
Signal
1011001010110100110100
Figure -17 Biphase Mark signal of SPDIF
Preamble cell-order
cell-order
(last cell "0") (last cell "1")
------------------------------------------------------
"B"
11101000 00010111
"M"
11100010 00011101
"W"
11100100 00011011
Preamble B:
Marks a word containing data for channel A (left) at the start of the data-block.
Preamble M:
www.cmedia.com.tw
Copyright © C-Media Electronics Inc.
Rev. 1.02 ︱ Page 25/16