YAC520 Datasheet, PDF (7/16 Pages) YAMAHA CORPORATION – High Grade Volume Control

YAC520
s Description of digital functions
• Serial data interface
HGVC1 is a simple three wire serial interface. SDATAI is a serial data input pin, SCLK is a serial clock
pin, and CSN is a chip select pin for writing volume value. 16 bit serial data is so formatted that SDATAI
is inputted in synchronous with rise edge of SCLK when CSN is “low” (MSB first).
Data is latched with the rise edge of CSN, and volume values of both left channel and right channel are
set into the register. Serial data is outputted from SDATAO in synchronous with fall edge of SCLK. This
data allows control by using daisy chain connection or confirmation of present volume value easily.
Note that the register value after power on is 0000h (muted state), and thus, the interface becomes valid
after the time t_PUP elapses.
CSN
SCLK
SDATAI
SDATAO
R1[7] R1[6] R1[5] R1[4] R1[3] R1[2] R1[1] R1[0] L1[7] L1[6] L1[5] L1[4] L1[3] L1[2] L1[1] L1[0]
R0[7] R0[6] R0[5] R0[4] R0[3] R0[2] R0[1] R0[0] L0[7] L0[6] L0[5] L0[4] L0[3] L0[2] L0[1] L0[0] R1[7]
• Daisy Chaining
Since HGVC1 adopts multi channel system, multiple devices can be connected with daisy chain
connection. When using the LSI in multi channel system, connection of the first SDATAO pin to the
second SDATAI pin, and the second SDATAO pin to the third SDATAI pin allows control of multiple
HGVC1s without requiring complex addressing. Volume data is inputted into the S/P(Serial/Parallel)
register of the individual HGVC1 by holding CSN “low” for 16 clocks * N (N represents the number of
HGVCs in the chain).
As the volume data inputted to the SDATAI of HGVC1(1) is shifted in the internal S/P register by 1 bit
per SCLK clock, 16 * N clocks are required to input volume data into S/P registers of all HGVC1(1) to
HGVC1(N). Note that the first 16-bit data is inputted to the S/P register of the HGVC1(N).
Finally, by setting CSN “High” after 16 clocks * N period, all data in the S/P registers are written into
the Control registers simultaneously to activate new volume data of all HGVC1s in the daisy chain.
Audio
Source
LOUT
LIN1
LIN2
RIN1
ROUT
HGVC1
RIN2
(N)
SDATAO SDATAI
CSN SCLK
•••
•••
Audio
Source
LOUT
LIN1
LIN2
RIN1
ROUT
HGVC1
RIN2
(2)
SDATAO SDATAI
CSN SCLK
Audio
Source
LOUT
LIN1
LIN2
RIN1
ROUT
HGVC1
RIN2
(1)
SDATAO SDATAI
CSN SCLK
Controller
CSN
SCLK
SDATAI
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
R_N[7:0]
L _N[7:0]
R_N-1[7:0]
•••
16(N-1)+1
•••
R₁[7:0]
L ₁[7:0]
16N
7