Datasheet

Rev. 0 | Page 50 of 72 | June 2010
ADSP-21469
S/PDIF Transmitter Input Data Timing
The timing requirements for the S/PDIF transmitter are given
in Table 47. Input signals are routed to the DAI_P20–1 pins
using the SRU. Therefore, the timing specifications provided
below are valid at the DAI_P20–1 pins.
Oversampling Clock (HFCLK) Switching Characteristics
The S/PDIF transmitter has an oversampling clock. This
HFCLK input is divided down to generate the biphase clock.
Table 47. S/PDIF Transmitter Input Data Timing
Parameter Min Max Unit
Timing Requirements
t
SISFS
1
Frame Sync Setup Before Serial Clock Rising Edge 3 ns
t
SIHFS
1
Frame Sync Hold After Serial Clock Rising Edge 3 ns
t
SISD
1
Data Setup Before Serial Clock Rising Edge 3 ns
t
SIHD
1
Data Hold After Serial Clock Rising Edge 3 ns
t
SITXCLKW
Transmit Clock Width 9 ns
t
SITXCLK
Transmit Clock Period 20 ns
t
SISCLKW
Clock Width 36 ns
t
SISCLK
Clock Period 80 ns
1
The serial clock, data, and frame sync signals can come from any of the DAI pins. The serial clock and frame sync signals can also come via PCG or SPORTs. PCG’s input can
be either CLKIN or any of the DAI pins.
Figure 36. S/PDIF Transmitter Input Timing
SAMPLE EDGE
DAI_P20–1
(TxCLK)
DAI_P20–1
(SCLK)
DAI_P20–1
(FS)
DAI_P20–1
(SDATA)
t
SITXCLKW
t
SITXCLK
t
SISCLKW
t
SISCLK
t
SISFS
t
SIHFS
t
SISD
t
SIHD
Table 48. Oversampling Clock (HFCLK) Switching Characteristics
Parameter Max Unit
HFCLK Frequency for HFCLK = 384 × Frame Sync Oversampling Ratio × Frame Sync <= 1/t
SIHFCLK
MHz
HFCLK Frequency for HFCLK = 256 × Frame Sync 49.2 MHz
Frame Rate (Fs) 192.0 kHz