AK4584_01 Datasheet, PDF (29/53 Pages) Asahi Kasei Microsystems – 24Bit 96kHz Audio CODEC with DIT/DIR

ASAHI KASEI
[AK4584]
„ Audio Interface Format
Five serial modes are supported as shown in Table 16, and are selected by the DIF2-0 bits. In all modes, the serial data is
in MSB first, 2’s compliment format. The SDTO is clocked out on the falling edge of BICK and the SDTI is latched on the
rising edge. The audio interface supports both master and slave modes. In master mode, BICK and LRCK are output with
the BICK frequency fixed to 64fs and the LRCK frequency fixed to fs.
When the format is equal or less than 20-bit (mode 0-1), LSBs in the sub-frame are truncated. In mode 2-4, the last 4LSBs
are auxiliary data (see Figure 10).
Mode 2, 3, 4 in SDTI input formats can be used for 16-20bit data by zeroing the unused LSBs.
sub-frame of IEC60958
0 34 78
preamble Aux.
LSB
11 12
27 28 29 30 31
VUCP
MSB
MSB
LSB
23
0
AK4584 Audio Data (SDTO, MSB First)
Figure 10. Bit Structure
Mode
0
1
2
3
4
DIF2
0
0
0
0
1
DIF1
0
0
1
1
0
DIF0
0
1
0
1
0
SDTO
SDTI
24bit, MSB justified 16bit, LSB justified
24bit, MSB justified 20bit, LSB justified
24bit, MSB justified 24bit, MSB justified
24bit, I²S Compatible 24bit, I²S Compatible
24bit, MSB justified 24bit, LSB justified
Table 16. Audio Data Format
LRCK
H/L
H/L
H/L
L/H
H/L
BICK
≥ 32fs
≥ 40fs
≥ 48fs
≥ 48fs
≥ 48fs
Default
MS0118-E-00
- 29 -
2001/11