SLES017 − SEPTEMBER 2001
5
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functional description
serial audio port
The serial audio port consists of a shift clock (SCLK pin), a left/right frame synchronization clock (LRCLK pin),
and a data input (SDIN pin). The serial audio port supports standard serial PCM formats (Fs = 44.1-kHz, 48-kHz,
88.2-kHz, 96-kHz, 176.4-kHz, or 192-kHz stereo). See the serial interface formats section.
system clocks—master mode and slave mode
The TAS5015 allows multiple system clocking schemes. Master mode indicates that the TAS5015 provides
system clocks to other parts of the system (M_S=1). Audio system clocks of frequency 128 Fs MCLK_OUT
(quad speed), 64 Fs SCLK, and Fs LRCLK are output from this device when it is configured in master mode.
Slave mode indicates that a system master other than the TAS5015 provides system clocks (LRCLK, SCLK,
and MCLK_IN) to the TAS5015 (M_S = 0). The TAS5015 operates with LRCLK and SCLK synchronized to
MCLK. The TAS5015 does not require any specific phase relationship between LRCLK and MCLK, but there
must be synchronization. In the slave mode, MCLK_OUT is driven low. Table 1 shows all the possible master
and slave modes.
sampling frequency
The normal sampling frequency is either 11.2896 MHz (Fs = 44.1 kHz) or 12.288 MHz (Fs = 48 kHz). Twice the
normal sampling frequency can be selected by using the DBSPD pin which allows usage of Fs = 88.2 kHz or
Fs = 96 kHz. In the double-speed slave mode (DBSPD = 1, M_S = 0), the external clock input is either
22.5796 MHz (Fs = 88.2 kHz) or 24.576 MHz (Fs = 96 kHz). Table 1 explains the proper clock selection.
Table 1. External Clock and External PLL Functions
DESCRIPTION M_S DBSPD DEM_EN DEM_SEL MCLK_IN
(MHz) HFCLK
(MHz) SCLK
(MHz) LRCLK
(KHz) MCLK_OUT
(MHz)
External PLL, master, normal
0 0
External PLL, master, normal
speed (see Notes 1 and 2) 1 0 1 0 − 90.3168 2.8224 44.1 11.2896
External PLL, master, normal
1 1
External PLL, master, normal
speed (see Notes 1 and 2) 1 0 0 0 − 98.304 3.072 48 12.288
External PLL, master, double
speed (see Notes 1 and 2) 1 1 0 0 − 90.3168 5.6448 88.2 22.5792
External PLL, master, double
speed (see Note 1 and 2) 1 1 0 0 − 98.304 6.144 96 24.576
External PLL, master, quad speed
(see Notes 1 and 2) 1 0 0 1 − 90.3168 11.2896 176.4 22.5792
External PLL, master, quad speed
(see Notes 1 and 2) 1 0 0 1 − 98.304 12.288 192 24.576
External PLL, slave, normal speed
0 0
External PLL, slave, normal speed
(see Notes 3, 4, and 5) 0 0 1 0 11.2896 90.3168 2.8224 44.1 11.2896
External PLL, slave, normal speed
1 1
External PLL, slave, normal speed
(see Notes 3, 4, and 5) 0 0 0 0 12.288 98.304 3.072 48 12.288
NOTES: 1. SCLK and LRCLK are outputs
2. MCLK_IN tied LOW
3. External MCLK connected to MCLK_IN input
4. SCLK and LRCLK are inputs
5. MCLK_OUT is a buffered version of the external MCLK input