SM5816AF_06 Datasheet, PDF (17/27 Pages) Nippon Precision Circuits Inc – 6-channel DSD-PCM Converter

SM5816AF
2fs PCM select external input data and external system clock output switching
(1) Switching to external input data
When SELEXT goes from LOW to HIGH, F2FLREX1 and F2CSWEX2 PCM data outputs are directly
switched from EXID1 and EXID2 inputs.
Similarly, F2LRCK and F2BCK are directly switched, regardless of the DIR2CK setting, from EXILRCK
and EXIBCK inputs.
(2) Switching to external system clock
The CKOUT output is switched from MCK or EXIMCK inputs, according to the state of SELEXT
SELEXT = “L”: MCK output
SELEXT = “H”: EXIMCK output
However, both MCK and EXIMCK should not be stopped during the switching interval to avoid a momen-
tary pulse from occurring when switching.
Also, the switching interval, from initial setting until both clocks have each switched 4 times, has a LOW-
level pulse that continues longer than the clock pulsewidth of each input clock.
After the switching operation finishes, the unused clock input may be stopped.
MCK
EXIMCK
SELEXT
CKOUT
OFF
(MCK OFF)
(EXIMCK ON)
(Switching time)
Figure 2. MCK → EXIMCK switching
MCK
EXIMCK
SELEXT
CKOUT
OFF
(EXIMCK OFF)
(MCK ON)
(Switching time)
Figure 3. EXIMCK → MCK switching
SEIKO NPC CORPORATION —17