ASAHI KASEI
[AK4101A]
2. Synchronous Mode (hardware controlled)
The AK4101A when configured in synchronous mode accepts 16 - 24 bit audio samples through the audio serial port
and provides dedicated pins for the control data and allows all channel status, user data and validity bits to be serially
input through port pins. This data is multiplexed, the parity bit generated, and the bit stream is biphase-mark encoded
and driven through an RS422 line driver. The four set of channels have individual channel status and user data pins.
2-1. Audio Routing Mode (Transparent Mode)
The AK4101A can be configured in audio routing mode (transparent mode) by ANS pin = TRANS pin = “1”. In this
mode, the channel status(C), user data(U) and validity(V) bits must pass through unaltered. The Block Start(B) signal is
configured as an input, allowing the transmit block structure to be slaved to the block structure of the receiver. The C, U
and V are now transmitted with the current audio sample. In audio routing mode, no CRCC bytes are generated and C
bits pass through unaltered. In audio routing mode, the FS0/CSN pin changes definition to AKMODE pin. When set
“H” the AK4101A can be configured directly with the AK4112B receiver. When set “L”, it may be used with other non-
AKM receivers. Setting the part with TRANS pin = “1” and ANS pin = “0” is illegal and places the chip into a test
mode.
Pin
Modes
Source for C, U and V bits
ANS
0
TRANS Synchronous/Asynchronous
Audio Routing
Normal mode
C Pin ORed Control Register
U Pin ORed Control Register
V Pin ORed Control Register
0
Asynchronous mode
Synchronous mode
0
1
1
1
0
1
(Test mode)
Normal mode
Audio routing mode
C,U and V pin
Table 2. Mode setting
BLS
C (or U,V)
C(R191)
C(L0)
C(R0) C(L1)
C(L31) C(R31) C(L32)
LRCK
(except I2S)
LRCK
(I2S)
SDTI
R191
L0
R0
L1
L31
R31
L32
Figure 1. Audio routing mode timing (AKMODE pin = “0”)
MS0250-E-00
2003/07
- 12 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
