ASAHI KASEI
[AK4317]
Serial Mode Control
The AK4317 can control output attenuation level, output mode, de-emphasis type and attenuation mode
via the serial interface.The serial data consists of two 8 bits for setting the attenuation level of each
channel and 8 bits for the mode control.
Figure 6 . Configuration of attenuator and mixer
L0-L7:
R0-R7:
S0-S3:
DEM:
Lch ATT data, L0=LSB, L7=MSB
Rch ATT data, R0=LSB, R7=MSB
Output mode Control
De-Emphasis Control
ATT mode Control
:FFH at RESET
:FFH at RESET
:1001 at RESET
:0 at RESET
ATC:
:0 at RESET
FS0,FS1: fs Control for de-emphasis Filter
:00 at RESET
Note 1: CCLK should be held "H" or "L" except writing to ATT & mode registers in order to avoid the
performance degradation.
Note 2: If the above serial mode control is not used, CS should be held "H".
Figure 7 . Serial mode control timing
1. Attenuator Operation
The AK4317 has individually controllable attenuator with linear scale and 256 levels for each channel.
Equation of attenuation level: ATT=20×Log10(Binary level/255)
FFH: 0dB
:
01H: -48.1dB
00H: Mute(Infinity zero:-∞)
The transition between ATT values is same as soft mute operation. When current value is ATT1 and new
value is set as ATT2, ATT1 gradually becomes ATT2 with same operation as soft mute. If new value is set
as ATT3 before reaching ATT2, ATT value gradually becomes ATT3 from the way of transition.
Cycle time of soft mute:Ts=1024/fs
When resetting, ATT value is set 00H(Infinity zero). ATT value gradually changes from 00H to FFH(0dB)
during Ts after exiting reset.
0172-E-01
1997/5
- 12 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
