SECTION 3
CLOCK CONSTRUCTION
[Regarding the clock source of this unit]
1.The clock source for IC614.(CPU : HD6413002) is X601 (10 MHz).
2.The clock source for IC613 (Clock IC : NJU6355) is X603 (32.768 kHz).
3.The clock sources for the digital audio system (AID, D/A, DPS, etc.) are X301 (48.6 MHz) and X901 (12.288 MHz).
[Regarding the clock of the digital audio system]
The condition of the digital audio system clock differs depending on whether the digital audio interface input is used (external) or not (internal).
The difference between internal (System Setup Input = Analog) and external (System Setup Input = Digital or both, and input is made into Digital IN) is the use of 12,288 MHz or the output of IC90l (Digital Audio Interface Receiver: pin @) MCK (256 fs) of CS8412. This is selected by the EXT/INT of pin @ of IC906 (HC153). (When internal it is L.)
*Pin @) MCK of IC901 differs according to the sampling frequency of the signal that is input to the digital audio interface. In case of 48 kHz it is 12.288 MHz and in case of 44.1 kHz it is 11.2896 MHz.
*When the clock source is external, the oscillation of the internal crystal X901 (12.288 MHz) is stopped in order to prevent interference between the clocks.
IC305 (Digital Filter: CXD8482), which is based on this master clock, outputs LRCK (=lfs), which is the sampling frequency for the whole system, from pin @ or 64 fs BCK from pin ® .
IC304 (AID converter: CXD8493) receives a clock of 128 fs from pin @ of IC305 (Digital Filter: CXD8482) and operates.
The master clock (1024 fs) of IC307 (D/A converter: CXD8505) is generated by the YCO block (Q904, Q905 and IC909, etc.). It uses
IC910 (PLL : TC8051AP) from LRCK, which is created by IC305 (Digital Filter: CXD8482), to lock. The 1024 fs clock that is oscillated
by YCO becomes the 256 fs output from pin @ (256 fso) of IC307 (D/A converter: CXD8505), and it is further divided by IC907 and
IC908 (Prescaler : HC163) to become lfs, after which it is fed back to IC910 (PLL : TC8051AP) to form a loop.
The master clock of IC602 and 604 (DSP : CXD2707) is fixed at X301 (48.6 MHz). The master clock of DSP is asynchronous with the sampling frequency, but the processing of the DPS signal is carried out at a LRCK (lfs) cycle.
*At the time of digital input (clock source = external) the master clock that is input to IC305 (Digital Filter: CXD8482) is changed to 256
fs which is output from pin @) of IC901 (Digital Audio Interface Receiver: CS8412), but all sequences besides that are the same as for the internal operation.
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