SRC4190 Datasheet, PDF (21/25 Pages) Burr-Brown (TI) – 192kHz Stereo Asynchronous Sample Rate Converters

LRCKO
BCKO
TDMI
t_LROS
t_LROH
t_TDMS
t_TDMH
FIGURE 12. Input Timing for TDM Mode.
The frame rate is equal to the output sampling frequency, f_s.
The BCKO frequency for the TDM interface is N x 64f_s, where
N is the number of devices included in the daisy chain. For
Master mode, the output BCKO frequency is fixed to the
reference clock (RCKI) input frequency. The number of
devices that can be daisy-chained in TDM mode is depen-
dent upon the output sampling frequency and the BCKO
frequency, leading to the following numerical relationship:
Number of Daisy-Chained Devices = (f_BCKO / f_s) / 64
Where:
f_BCKO = Output Port Bit Clock (BCKO), 27.136 MHz maximum
f_s = Output Port Sampling (or LRCKO) Frequency, 212kHz
maximum.
This relationship holds true for both Slave and Master modes.
Figures 13 and 14 show typical connection schemes for the
TDM mode. Although the TMS320C671x DSP family is
shown as the audio processing engine in these figures, other
TI digital signal processors with a multi-channel buffered
serial port (McBSP^TM) may also function with this arrange-
ment. Interfacing to processors from other manufacturers is
also possible. Refer to Figure 7 in this data sheet, along with
the equivalent serial port timing diagrams shown in the DSP
data sheet, to determine compatibility.
SRC4190
Slave #N
TDMI
SDOUT
LRCKO
BCKO
RCKI
SRC4190
Slave #2
TDMI
SDOUT
LRCKO
BCKO
RCKI
FIGURE 13. TDM Interface where all Devices are Slaves.
SRC4190
Slave #1
TDMI
SDOUT
LRCKO
BCKO
RCKI
TMS320C671x
McBSP
DRn
n = 0 or 1
FSRn
CLKRn
CLKIN or CLKSn
Clock
Generator
SRC4190
Master
TDMI
SDOUT
LRCKO
BCKO
RCKI
SRC4190
Slave #2
TDMI
SDOUT
LRCKO
BCKO
RCKI
SRC4190
Slave #1
TDMI
SDOUT
LRCKO
BCKO
RCKI
FIGURE 14. TDM Interface where one Device is Master to Multiple Slaves.
SRC4190
SBFS023A
www.ti.com
TMS320C671x
McBSP
DRn
n = 0 or 1
FSRn
CLKRn
CLKIN or CLKSn
Clock
Generator
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