NJU26125VC2 NJRC [New Japan Radio], NJU26125VC2 Datasheet - Page 9

• Manufacturer Part Number: NJU26125VC2
• Description: Seat Positioning Surround Decoder
• Manufacturer: NJRC [New Japan Radio]

2. Digital Audio Clock
Ver.2010-07-01
Table 5 SLAVEb, BCK, LR, MCK
SLAVEb and firmware
2.1 Audio Clock
Firmware: Master
Firmware: Slave
SLAVEb=”Low”
Firmware: each
Digital audio data needs to synchronize and transmit between digital audio systems.
The NJU26125 - master mode / slave mode - both of the modes are supported.
- In Master mode;
- In Slave mode;
A device in the system generates the transmitted clock become a standard. The other devices are set
according to the transmitted clock. The device generating transmitted clock is called Master Device. The
device according to the transmitted clock is called Slave Device. NJU26125 usually operates Slave Device.
However, NJU26125 becomes Master Device in case of SLAVEb set the High level and NJU26125 is set
Master mode by firmware command. In Slave mode, clock inputted to the BCK pin and the LR pin is used
to digital audio signal transmission. In Master mode, clock outputted to the BCK pin and the LR pin is used
to digital audio signal transmission.
Three kinds of clocks are needed for digital audio data transfer.
In SLAVEb is High level, the MCK pin becomes buffer output pin for input clock to the CLK pin after
NJU26125 resets. The MCK output is able to be stopped by firmware command.
In SLAVEb is Low level, MCK pin becomes system clock input pin. It is not insure to change the logical
switch of SLAVEb pin during operating. If it is necessary to change SLAVEb pin setting, reset NJU26125
every time.
In NJU26125 is used by 256 times of Maximum sampling frequency, NJU26125 is able to output LR clock
of same sampling rate and two-third times of sampling rate, and output BCK clock of 32 times sampling
rate and 64 times sampling rate in Master mode.
SLAVEb=”H”
SLAVEb=”H”
(1) LR clock (LR) is needed by serial-data transmission. It is the same as the sampling
(2) Bit clock (BCK) is needed by serial-data transmission. It becomes the multiple of LR clock.
(3) Master clock (MCK) is needed by A/D, D/A converter, etc. It becomes the multiple of LR
setting
frequency of a digital audio signal.
clock. It is not related to serial audio data transmission.
Use the clock of BCKO and a LRO pin output clock for digital audio data transfer.
The clock output from a master device is needed for the input terminal of BCKI and LRI.
DSP Master operating
DSP slave operating
LR clock output
LR clock input
LR pin
DSP slave operating
Bit clock output
Bit clock input
DSP Master
operating
BCK pin
NJU26125 operating clock input
Master clock output
(Buffer of CLK)
(MCK or CLK)
MCK pin
NJU26125
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