ADAU1445 Analog Devices, ADAU1445 Datasheet - Page 58

• Manufacturer Part Number: ADAU1445
• Manufacturer: Analog Devices

Specifications of ADAU1445

• Instructions/cycles: 3584
• Digital I/o Channels: 24/24
• Analog I/o Channels: 0/0
• Product Description: Digital audio processor with flexible audio routing matrix, 8 × 2-channel ASRC

ADAU1442/ADAU1445/ADAU1446
ASYNCHRONOUS SAMPLE RATE CONVERTERS
The integrated sample rate converters of the ADAU1442/
ADAU1445 processors can be configured in various ways to
facilitate asynchronous connectivity to other components in the
audio system. The sample rate converters operate completely
independent of the serial ports and DSP core, connecting via
the flexible audio routing matrix.
ASRC MODES AND SETTINGS
Table 36. Addresses of ASRC Modes Registers
Decimal
57601
57603
57665
57667
Stereo ASRC[3:0] Lock Status and Mute Register
(Address 0xE101)
Table 37. Bit Descriptions of Register 0xE101
Bit
Position
[15:12]
11
10
9
8
[7:4]
3
2
1
0
Every sample rate converter pair for Stereo ASRC[3:0] can be
muted. This function is controlled by a single 12-bit register.
The mute bits (Bits[3:0]) are active high; therefore, a value of 1
mutes the corresponding ASRC, and a value of 0 unmutes the
corresponding ASRC. The muting is done with a volume ramp
and is click and pop free. If desired, the mute ramp can be
disabled (see the Stereo ASRC[3:0] Mute Ramp Disable Register
(Address 0xE103) section).
When the device is powered up and brought out of reset, the
ASRC lock bits default to a value of 0. When the master clocks
to the ASRC are enabled (see the Master Clock Enable Switch
Register (Address 0xE280) section), the corresponding ASRC
lock bits are set to 1, and the outputs are automatically muted.
Address
Hex
E101
E103
E141
E143
Description
Reserved
Stereo ASRC 3 (Channel 6, Channel 7)
lock status (read only)
Stereo ASRC 2 (Channel 4, Channel 5)
lock status (read only)
Stereo ASRC 1 (Channel 2, Channel 3)
lock status (read only)
Stereo ASRC 0 (Channel 0, Channel 1)
lock status (read only)
Reserved
Stereo ASRC 3 (Channel 6, Channel 7) mute
Stereo ASRC 2 (Channel 4, Channel 5) mute
Stereo ASRC 1 (Channel 2, Channel 3) mute
Stereo ASRC 0 (Channel 0, Channel 1) mute
Name
Stereo ASRC[3:0] lock
status and mute
Stereo ASRC[3:0] mute
ramp disable
Stereo ASRC[7:4] lock
status and mute
Stereo ASRC[7:4] mute
ramp disable
Read/Write
Word Length
16 bits (2 bytes)
16 bits (2 bytes)
16 bits (2 bytes)
16 bits (2 bytes)
Default
0
0
0
0
0
0
0
0
Rev. C | Page 58 of 92
When an ASRC's output rate is set (see the ASRC Output Rate
Select Pairs[7:0] Registers (Address 0xE088 to Address 0xE08F)
section) and it locks to a valid output clock, the corresponding
lock bit changes from 1 to 0. This signifies that the ASRC has
found the target clock rate and locked to it. From that moment
onward, the lock bit remains at 0 until the device is reset. Changing
the target rate setting or removing the output clock from the
ASRC will not cause its lock bit to change from 0 back to 1.
In the case of the ADAU1446, setting these registers does not
affect system operation in any way.
Stereo ASRC[3:0] Mute Ramp Disable Register
(Address 0xE103)
Table 38. Bit Descriptions of Register 0xE103
Bit
Position
[15:1]
0
This single-bit register controls the mute behavior of Stereo
ASRC[3:0] (Channels[7:0]). When Bit 0 is set to the default (0),
Stereo ASRC[3:0] (Channels[7:0]) mute with a volume ramp.
When Bit 0 is set to 1, Stereo ASRC[3:0] mute abruptly. In
addition, setting this bit to 1 ignores the ASRC mute bits
(Bits[3:0]) in Register 0xE101 (see the Stereo ASRC[3:0] Lock
Status and Mute section); therefore, a mute only occurs on a loss
of lock.
In the case of the ADAU1446, setting this register does not
affect system operation in any way.
Stereo ASRC[7:4] Lock Status and Mute Register
(Address 0xE141)
Table 39. Bit Descriptions of Register 0xE141
Bit
Position
[15:12]
11
10
9
8
[7:4]
3
2
1
0
Description
Reserved
Stereo ASRC 7 (Channel 14, Channel 15)
lock status (read only)
Stereo ASRC 6 (Channel 12, Channel 13)
lock status (read only)
Stereo ASRC 5 (Channel 10, Channel 11)
lock status (read only)
Stereo ASRC 4 (Channel 8, Channel 9)
lock status (read only)
Reserved
Stereo ASRC 7 (Channel 14, Channel 15) mute
Stereo ASRC 6 (Channel 12, Channel 13) mute
Stereo ASRC 5 (Channel 10, Channel 11) mute
Stereo ASRC 4 (Channel 8, Channel 9) mute
Description
Reserved
Stereo ASRC[3:0] (Channels[7:0]) mute ramp
disable
0 = enable ramp
1 = disable ramp
Default
0
Default
0
0
0
0
0
0
0
0