TI TLV320AIC27CPFB

TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
D
D
D
D
D
D
D
D
3.3-V or 5-V Operation
18-Bit Stereo Codec
S/N Ratio >95 dB
Multiple Stereo Input Mixer
Mono and Stereo Volume Control
48-Pin TQFP Package
Power Management Features
Low-Power Implementation
D
D
D
D
D
D
D
D
Four DAC Channels, Stereo ADC
Balanced Mixer Architecture
Variable Rate Audio and Modem Support
Analog 3D Stereo Enhancement
Line Level Outputs
Master/Slave ID Selection
AC97 Rev. 2.1 Compliant
Complete TI-DSP-CODEC Solution
description
The TLV320AIC27 comprises a stereo 18-bit codec (that is, 2 ADCs and 4 DACs), plus a comprehensive analog
mixer with four sets of stereo inputs, plus one phone input, two microphone inputs, and one PC-beep input.
Additionally, on-chip reference circuits generate the necessary bias voltages for the device, and a bidirectional
serial interface allows transfer of control data, DAC, and ADC words to and from the AC’97 controller. The
TLV320AIC27 is fully compliant with Revision 2.1 of the AC’97 specification.
The TLV320AIC27 has the ADC and DAC functions implemented using oversampled, or sigma-delta,
converters and uses on-chip digital filters to convert these one-bit signals to and from the 48 ksps, 16/18-bit PCM
words that the AC’97 controller requires. The digital and analog sections of the device are powered separately
to optimize performance, and 3.3-V digital and 5-V analog supplies may be used on the same device to further
optimize performance. Digital IOs are 5-V tolerant when the analog supplies are 5 V. Therefore, the
TLV320AIC27 may be connected to a controller running on 5-V supplies, but use 3.3 V for the digital section
of the TLV320AIC27. The TLV320AIC27 is also capable of operating with a 3.3-V supply only (digital and
analog).
When using the TLV320AIC27 codec, the AC’97 controller may be selected from Texas Instruments family of
DSPs. The combination of the computing power of the TI DSP and the high audio performance of the
TLV320AIC27 constitutes a complete solution for various applications. The ability to power down sections of
the device selectively, and the option to alternate the master clock, and hence sample rates, makes such
applications as telecommunications, audio, teleconferencing, and USB, possible.
Additional features added to the Intel AC’97 specification, such as the EAPD (external amplifier power down)
bit and internal connection of PC beep to the outputs when the device is reset are supported, as well as optional
features such as variable sample rate support.
There are four modes of operation.
D
D
D
D
Basic (2-channel)
6-channel I2S
Quad
Modem
ESD Sensitive Device. This device is manufactured on a CMOS process. It it therefore generically susceptible to damage from
excessive static voltages. Proper ESD precautions must be taken during handling and storage of this device. As per JEDEC
specifications A112-A and A113-B, this product requires specific storage conditions prior to surface mount assembly. It has been
classified as having a Moisture Sensitivity Level of 2 and as such will be supplied in vacuum-sealed moisture barrier bags.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Intel is a trademark of Intel Corporation.
Copyright  2000, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
POST OFFICE BOX 655303
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1
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
terminal assignments
MODE0
AFILT1
VREFOUT
VREF
AVSS1
AVDD1
LINEOUTR
LINEOUTL
CX3D2
CX3D1
CAP2
CAP1
PFB PACKAGE
(TOP VIEW)
36 35 34 33 32 31 30 29 28 27 26 25
MONOOUT
AVDD2
LNLVLOUTL
MODE1
LNLVLOUTR
AVSS2
GPIO
GPIO
CID0
CID1
EAPD
GPIO
37
24
38
23
39
22
40
21
41
20
42
19
43
18
44
17
45
16
46
15
47
14
13
48
2 3 4
5 6 7
8
9 10 11 12
DVDD1
XTLIN
XTLOUT
DVSS1
SDATAOUT
BITCLK
DVSS2
SDATAIN
DVDD2
SYNC
RESETB
PCBEEP
1
ORDERING INFORMATION
TA
2
PACKAGE
48-TQFP PFB
0°C to 70°C
TLV320AIC27CPFB
–40°C to 85°C
TLV320AIC27IPFB
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
LINEINR
LINEINL
MIC2
MIC1
CDR
CDGND
CDL
VIDEOR
VIDEOL
AUXR
AUXL
PHONE
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
functional block diagram—two-channel mode
VOL/
MUTE
VOL/
MUTE
∑
VOL/
MUTE
(35,36)
LINEOUT
VOL/
MUTE
(39,41)
LNLVLOUT
∑
KEY:
MUX
VOL/
MUTE
(37)
MONOOUT
MONO
STEREO
VOL
VOL/
MUTE
VOL/
MUTE
VOL/
MUTE
STEREO
DAC
SRC
(47) EAPD
3D
(6) BITCLK
∑
∑
SERIAL
I/F
(10) SYNC
(8) SDATAIN
(5)
SDATAOUT
VOL/
MUTE
(11) RESETB
VOL/
MUTE
CD (18,20)
LINEIN (23,24)
VIDEO (16,17)
AUX (14,15)
PHONE (13)
PCBEEP (12)
MIC[1] (21)
MIC[2] (22)
VOL
STEREO
DAC
RECORD
MUX
AND
MUTE
MUX
0dB/
20dB
SRC
MASTER/
SLAVE
SELECT
OSC
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(45) CID[0]
(46) CID[1]
(2) XTLIN
(3) XTLOUT
3
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
functional block diagram—6-channel I2S, quad, and modem modes
VOL/
MUTE
VOL/
MUTE
∑
VOL/
MUTE
VOL/
MUTE
(35,36)
LINEOUT
(FRONT)
VOL/
MUTE
(39,41)
LINEOUT
(REAR)
VOL/
MUTE
(37)
MONOOUT
REV. 2.1
SWITCH
∑
∑
VOL/
MUTE
MUX
VOL/
MUTE
KEY:
REAR
STEREO
DAC
SRC
(40) MODE1
MONO
STEREO
VOL/
MUTE
VOL/
MUTE
VOL/
MUTE
VOL/
MUTE
FRONT
STEREO
DAC
(30) MODE0
SRC
(47) EAPD
3D
SERIAL
I/F
(10) SYNC
(8) SDATAIN
∑
∑
(6) BITCLK
(5)
SDATAOUT
VOL/
MUTE
(11) RESETB
VOL/
MUTE
CD (18,20)
LINEIN (23,24)
VIDEO (16,17)
AUX (14,15)
PHONE (13)
PCBEEP (12)
MIC[1] (21)
MIC[2] (22)
VOL
STEREO
ADC
RECORD
MUX
AND
MUTE
MUX
SRC
MASTER/
SLAVE
SELECT
General
IO
Supprt
0dB/
20dB
OSC
4
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
(45) CID[0]
(46) CID[1]
(43,44,48)
GPIO[1:3]
(2) XTLIN
(3) XTLOUT
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
Terminal Functions
TERMINAL
NAME
NO.
TYPE
DESCRIPTION
AFILT1
29
Analog output
Buffered CAP2. This terminal has an internal connection.
VIDEOL
16
Analog input
Mixer input, typically for VIDEO signal
VIDEOR
17
Analog input
Mixer input, typically for VIDEO signal
AUXL
14
Analog input
Mixer input, typically for AUX signal
AUXR
15
Analog input
Mixer input, typically for AUX signal
AVDD1
AVDD2
25
Supply
Analog positive supply
38
Supply
Analog positive supply
AVSS1
AVSS2
26
Supply
Analog ground supply, chip substrate
42
Supply
Analog ground supply, chip substrate
BITCLK
6
Digital output
Serial interface clock output to AC’97 controller
CAP1
31
Analog output
Buffered CAP2. This terminal has an internal connection.
CAP2
32
Analog input
Reference input/output; pulls to midrail if not driven
CDGND
19
Analog input
CD input common-mode reference (ground)
CDL
18
Analog input
Mixer input, typically for CD signal
CDR
20
Analog input
Mixer input, typically for CD signal
CID0
45
Digital input
Master/slave ID select (internal pullup)
CID1
46
Digital input
Master/slave ID select (internal pullup)
CX3D1
33
Analog output
Output pin for 3D difference signal
CX3D2
34
Analog input
Input pin for 3D difference signal
DVDD1
1
Supply
Digital positive supply
DVDD2
9
Supply
Digital positive supply
DVSS1
4
Supply
Digital ground supply
DVSS2
7
Supply
Digital ground supply
EAPD
47
Digital output
External amplifier power down/GPO
GPIO
43, 44, 48
General-purpose I/O
LINEINL
23
Analog input
Mixer input, typically for LINE signal
LINEINR
24
Analog input
Mixer input, typically for LINE signal
LINEOUTL
35
Analog output
Main analog output for left channel
LINEOUTR
36
Analog output
Main analog output for right channel
LNLVLOUTL
39
Analog output
Left channel line-level output
LNLVLOUTR
41
Analog output
Right channel line-level output
MIC1
21
Analog input
Mixer input with extra gain, if required
MIC2
22
Analog input
Mixer input with extra gain, if required
MONOOUT
37
Analog output
Main mono output
MODE0
30
Digital input
Mode select pin, internal pulldown
MODE1
40
Digital input
Mode select pin, internal pulldown
PCBEEP
12
Analog input
Mixer input, typically for PCBEEP signal
PHONE
13
Analog input
Mixer input, typically for PHONE signal
RESETB
11
Digital input
NOT reset input (active low, resets registers)
SDATAIN
8
Digital output
Serial-data output to AC’97 controller
SDATAOUT
5
Digital input
Serial-data input
SYNC
10
Digital input
Serial-interface sync pulse from AC’97 controller
VREF
27
Analog output
Buffered CAP2. This terminal has an internal connection.
VREFOUT
28
Analog output
Reference for microphones; buffered CAP2
XTLIN
2
Digital input
Clock-crystal connection or clock input (XTAL not used)
XTLOUT
3
Digital output
Clock-crystal connection
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5
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Digital supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to 7 V
Analog supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to 7 V
Voltage range digital inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DVSS –0.3 V to DVDD +0.3 V
Voltage range analog inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AVDD –0.3 V to AVDD +0.3 V
Operating temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C
Lead temperature (soldering 10 seconds) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C
Lead temperature (soldering 2 minutes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
recommended operating conditions
MIN
TYP
MAX
UNIT
Digital supply range, DVDD
3.3 to 5
V
Analog supply range, AVDD
3.3 to 5
V
0
V
Digital ground, DVSS
Analog ground, AVSS
0
Analog supply current
DVDD, AVDD = 5 V
Digital supply current
DVDD, AVDD = 5 V
Standby supply current (all PRs set)
DVDD, AVDD = 5 V
Analog supply current
DVDD, AVDD = 3.3 V
22
Digital supply current
DVDD, AVDD = 3.3 V
Standby supply current (all PRs set)
DVDD, AVDD = 3.3 V
6
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35
V
50
mA
30
50
mA
150
600
µA
33
mA
20
22
mA
100
150
µA
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
electrical characteristics, AVDD = 5 V, DVDD = 3.3 V, GND = 0 V, TA = 0°C to 70°C (unless otherwise
noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Digital Logic Levels (DVDD = 3.3 V or 5 V)
VIL
VIH
Input low level
VOL
VOH
Output low
AVSS – 0.3
2.2
Input high level
0.8
V
AVDD + 0.3
0.1 × DVDD
V
0.9 × DVDD
Output high
V
V
Analog I/O Levels (input signals on any inputs, outputs on LINEOUT L, R, and MONOOUT)
Input level
Minimum input
impedance = 10 kΩ
AVSS –100 mV
Output level
Into 10 kΩ load
AVSS +100 mV
Near rail
to rail
AVDD +100 mV
V
AVDD –100 mV
V
Reference Levels
CAP2
Reference input/output
2/5 AVDD
CAP2 impedance
AVDD/2
75
3/5 AVDD
V
kΩ
VREF
Mixer reference
Buffered
CAP2
V
VREFOUT
MIC reference
Buffered
CAP2
V
CAP1
ADC reference
Buffered
CAP2
V
AFILT1
DAC reference
Buffered
CAP2
V
VREF current source (pins CAP1, AFILT2,
VREF and VREFOUT)
AVDD = 3 V
5
15
mA
VREF current source (pins CAP1, AFILT1,
VREF and VREFOUT)
AVDD = 5 V
3
5
mA
85
95
dB
1
Vrms
DAC Circuit Specifications (AVDD = 5 V) 48-kHz sampling
SNR A-weighted (see Note 1)
Full-scale output voltage
VREF = 2.5 V
THD
–3-dB full-scale input
Frequency response
74
96
dB
20
19 200
Hz
Transition band
19 200
28 800
Hz
Stop band
28 800
Out of band rejection
dB
–100
dB
40
dB
75
90
dB
1
Vrms
80
95
Spurious-tone reduction
PSRR
Hz
–40
20 Hz to 20 kHz
ADC Circuit Specifications (AVDD = 5 V) 48-kHz sampling
SNR A-weighted (see Note 1)
ADC input for full-scale output
VREF = 2.5 V
THD
–6-dB voltage input
Frequency response
dB
20
19 200
Hz
Transition band
19 200
28 800
Hz
Stop band
28 800
Stop-band rejection
PSRR
Hz
–74
20 Hz to 20 kHz
dB
40
dB
NOTE 1: SNR is the ratio of 0-dB signal output level to the output level with no signal, measured A-weighted over a 20 Hz to 20 kHz bandwidth.
POST OFFICE BOX 655303
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7
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
electrical characteristics, AVDD = 5 V, DVDD = 3.3 V, GND = 0 V, TA = 0°C to 70°C (unless otherwise
noted) (continued)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Mixer Circuit Specifications (AVDD = 5 V) 48-kHz sampling
SNR CD path A-weighted (see Note 1)
90
95
SNR other paths A-weighted (see Note 1)
85
95
AVSS
1.0
1
1.8
Vrms
74
90
dB
Maximum input voltage
Maximum output voltage on LINEOUT
THD
0-dB voltage input
Frequency response (±1 dB)
20
Input impedance (CD inputs)
At any gain
Input impedance (other mixer inputs)
Input impedance mic inputs
PSRR
dB
dB
AVDD
20000
15
Vrms
Hz
kΩ
At maximum gain
10
20
30
At 0-db gain
50
100
150
At maximum gain
10
20
30
At 0-db gain
55
110
165
kΩ
kΩ
20 Hz to 20kHz
40
dB
96
dB
Full scale output voltage
VREF = 1.65 V
0.7
Vrms
THD
–3-dB full-scale input
90
dB
DAC Circuit Specifications (AVDD = 3.3 V) 48-kHz sampling
SNR A-weighted (see Note 1)
Frequency response
66
20
Hz
Transition band
19200
19200
Hz
Stop band
28800
28800
Hz
Out-of-band rejection
Spurious-tone reduction
PSRR
20 Hz to 20 kHz
–40
dB
–100
dB
40
dB
85
dB
0.7
Vrms
80
dB
ADC-Circuit Specifications (AVDD = 3.3 V) 48-kHz sampling
SNR A-weighted (see Note 1)
ADC input for full-scale output
VREF = 1.65 V
THD
–6-dB voltage input
Frequency response
74
20
19200
Hz
Transition band
19200
28800
Hz
Stop band
28800
Stop-band rejection
Hz
–74
PSRR
20 Hz to 20 kHz
dB
40
dB
NOTE 1: SNR is the ratio of 0-dB signal output level to the output level with no signal, measured A-weighted over a 20 Hz to 20 kHz bandwidth.
8
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
electrical characteristics, AVDD = 5 V, DVDD = 3.3 V, GND = 0 V, TA = 0°C to 70°C (unless otherwise
noted) (continued)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Mixer-Circuit Specifications (AVDD = 3.3 V) 48 kHz sampling
SNR CD path A-weighted (see Note 1)
92
SNR other paths A-weighted (see Note 1)
92
Maximum input voltage
Maximum output voltage on LINEOUT
THD
0-dB voltage input
Frequency response (±1 dB)
74
Input impedance (other mixer inputs)
dB
0.66
Vrms
0.66
Vrms
90
20
Input impedance (CD inputs)
dB
dB
20000
At any gain
15
At maximum gain
20
Hz
kΩ
kΩ
At 0-dB gain
100
Input impedance mic inputs
At any gain
30
kΩ
PSRR
20 Hz to 20 kHz
40
dB
Clock-Frequency Range
Crystal clock
24.576
MHz
BIT_CLK frequency
12.288
MHz
48.0
kHz
SYNC frequency
NOTE 1: SNR is the ratio of 0-dB signal output level to the output level with no signal, measured A-weighted over a 20 Hz to 20 kHz bandwidth.
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TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
detailed description
3D stereo enhancement
This device contains a stereo-enhancement circuit, designed to optimize the listening experience when the
device is used in a typical PC-operating environment (that is, with a pair of speakers placed either side of the
monitor with little spatial separation). This circuit creates a differential signal by subtracting left and right channel
playback data, then filters this difference signal using low-pass and high-pass filters whose time constants are
set using external capacitors connected to the CX3D pins 33 and 34. Typical values of 100 nF and 47 nF set
high-pass and low-pass poles at about 100 Hz and 1 kHz respectively. This frequency band corresponds to the
range over which the ear is most sensitive to directional effects.
The filtered difference signal is gain-adjusted by an amount set using the four-bit value written to register 22h
bits 3 to 0. Value 0h is disabled, and value Fh is maximum effect. A typical value of 8h is optimum. The user
interface most typically uses a slider type of control to allow the user to adjust the level of enhancement to suit
the program material. Bit D13 3D in register 20h is the overall 3D-enable bit. The capability register 00h reads
back the value 11000 in bits D14 to D10. This corresponds to decimal 24, which is registered with Intel as Texas
Instruments Stereo Enhancement.
Note that the external capacitors setting the filtering poles applied to the difference signal can be adjusted in
value, or even replaced with a direct connection between the pins. When such adjustments are made, the
amount of difference signal fed back into the main signal paths can be significant. This can cause large signals
which may limit, distort, or overdrive signal paths or speakers. Adjust these values carefully to select the desired
acoustic effect.
There is no provision for pseudo-stereo effects. Mono signals have no enhancement applied if they are in phase
and have the same amplitude.
Signals from the PCM DAC channels do not have stereo enhancement applied. It is assumed that these signals
have already been processed digitally with any required 3D-enhancement effect. Applying the analog
3D-enhancement will corrupt the digital effect. This is equivalent to setting the POP bit in register 20h. As a
result, the readback value of this bit is fixed as 1, and attempts to change it will be ignored. The POP bit is set
to one and cannot be reset.
variable sample rate support
The DACs and ADCs on this device support all the recommended sample rates specified in the Intel Revision
2.1 specification for both audio and modem rates. Default rates are 48 ksps. If alternative rates are selected,
the AC’97 interface continues to run at 48 kw/s (kilowords per second), but data is transferred across the link
in bursts such that the net sample rate selected is achieved. It is up to the AC’97 Revision 2.1-compliant
controller to ensure that data is supplied to the ac link, and received from the ac link at the appropriate rate.
The device supports on-demand sampling. That is, when the DAC signal-processing circuits need another
sample a request is sent to the controller, which must respond with a data sample in the next frame it sends.
For example, if a rate of 24 ksps is selected, on average the device requests a sample from the controller every
other frame, for each of the stereo DACs. Note that if an unsupported rate is written to one of the rate registers,
the rate defaults to the nearest rate supported. The register then responds when interrogated with the supported
rate the device has defaulted to.
10
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TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
variable sample rate support (continued)
ADCs are controlled similarly but with one difference: normally the left and right-channel ADCs sample at the
same rate.
Table 1. Variable Sample Rates Supported
AUDIO
SAMPLE RATE
CONTROL VALUE
D15–D0
MODEM
SAMPLE RATE
CONTROL VALUE
D15–D0
8000
1F40
7200
1C20
11025
2B11
8228.57 (57600/7)
2024
16000
3E80
8400
20D0
22050
5622
9000
2328
44100
AC44
9600
2580
48000
BB80
10285.71 (72000/7)
282D
12000
2EE0
13714.28 (96000/7)
3592
19200
4B00
24000
5DC0
Table 2 shows which registers control which DAC rates, versus mode and ID selected.
Table 2. Variable Rate Register Location Versus Mode and ID
MODE
Rev 2.1 mode (00)
Rev 2.1 6-channel mode (01)
Quad mode (10)
ID
FRONT DAC RATE
REGISTER
00 and 01
2Ch
10
2Eh
11
2Ch (center) and 30h (LFE)
00 and 01
2Ch
10
2Eh
REAR DAC RATE
REGISTER
ADC RATE
REG
32h
32h
11
2Ch (center) and 30h (LFE)
00 and 01
2Ch
2Eh
10
2Eh
2Ch
11
2Ch (center) and 30h (LFE)
2Eh
32h
gain control register location versus mode and ID
Depending on the operational mode and ID of the device, the various gain control registers have locations in
the register map that may change. For example, if the codec is configured as ID 10, it means that the device
will be converting the rear surround DAC data. In this case, the surround DAC volume word written to register
38h is now used to control the master volume control, rather than the normal master volume 02h. In addition,
when the surround volume mute control is written as demute, mute in the DAC PGA register 18h is automatically
overridden. Then the user does not have to make an unexpected additional write to register 18h to demute the
DAC PGA.
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SLAS253 – MARCH 2000
gain control register location versus mode and ID (continued)
Table 3. Gain Control Register Location Versus Mode and ID
CODEC
ID
CONTROL
REG
Front DAC PGA
0x
10
11
18h
Muted (bit 15)
AND with 38h, 7, 15
AND with 36h, 7, 15
Muted (bit 15)
AND with 38h, 7, 15
AND with 36h, 7, 15
Muted (bit 15)
AND with 38h, 7, 15
AND with 36h, 7, 15
Rear DAC PGA
0x
10
11
70h
Muted (bit 15) and
powered off
Not muted (bit 15)
AND with 02h, 15
AND with 38h, 7, 15
AND with 04h, 15
Front mixer
0x
10
11
72h
Not muted (bit 15)
Not muted (bit 15)
Not muted (bit 15)
Rear mixer
0x
10
11
74h
Permanently muted
Not muted (bit 15)
Permanently muted
Front volume
0x
10
11
02h
38h
36h
Muted (bit 15)
Muted (7 and 15)
Muted (7 and 15)
Muted (bit 15)
Muted (7 and 15)
Muted (7 and 15)
Muted (bit 15)
Muted (7 and 15)
Muted (7 and 15)
Rear volume
0x
10
11
04h
Muted (bit 15) Rev 2.1
switch enabled
Muted (7 and 15)
Muted (bit 15)
Muted (7 and 15)
Muted (bit 15)
PGA
REV 2.1 MODE (0x)
MUTE DEFAULT
QUAD MODE (10)
MUTE DEFAULT
MODEM MODE (11)
master/slave ID0/1 support
TLV320AIC27 supports operation as either a master or a slave codec. Configuring the device as master or slave
is accomplished by tying together the CID pins CID0 and CID1 (pins 45 and 46 ).
Fundamentally, a device identified as a master (ID = 00) produces BITCLK as an output, whereas a slave (any
ID but 00) must be provided with BITCLK as an input. The obvious implication is that if the master device on
an ac link is disabled, the slave devices cannot function.
The AC’97 Revision 2.1 specification defines the CID pins as having inverting sense and being provided with
internal weak pull ups. Therefore, if no connections are made to the CID0/1 pins, then these pins pull hi and
an ID = 00 (or master) is selected. External connections to ground select other IDs.
Table 4. ID Selection
12
PIN 45 CID0
PIN 46 CID1
ID SELECTED
MASTER OR
SLAVE
BITCLK
NC
NC
00
Master
Output
NC
Ground
01
Slave
Input
Ground
NC
10
Slave
Input
Ground
Ground
11
Slave
Input
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SLAS253 – MARCH 2000
master/slave ID0/1 support (continued)
The TLV320AIC27 supports the AMAP function, whereby selection of an ID automatically maps the data from
the interface onto the PCM DACs.
Table 5. Default Slot to DAC Mappings Based on Codec ID
AC-LINK FRAME DATA
USED FOR DACs
CODEC ID
PCM LEFT DAC
USES DATA FROM
SLOT NUMBER
PCM RIGHT DAC
USES DATA FROM
SLOT NUMBER
COMMENTS
00
3
4
Original definition (master)
01
3
4
Original definition (docking)
10
7
8
Left/right surround channels
11
6
9
Center/LFE channels
The codec ID is available to the controller via register 28h and C3, bits D15 and D14
The previous automatic mapping of data to slots is extended when the device is operated in the alternative
modes selectable via the mode pins. In these cases the selection of which data slots are mapped onto internal
DACs or I2S outputs is accomplished as shown in Table 6. Note that I2S enable bit must be set.
Table 6. Slot to DAC and Mapping Based on Mode and Codec ID
MODE
Rev 2.1 (00)
Rev 2
R
2.1
1
6-channel (01)
Quad (10)
Modem (11)
CODEC
ID
SLOTS MAPPED
TO FRONT DACs
00 or 01
3 and 4
10
7 and 8
11
6 and 9
00 or 01
3 and 4
10
7 and 8
11
6 and 9
00 or 01
3 and 4
10
7 and 8
11
6 and 9
00 or 01
3 and 4
10
7 and 8
11
6 and 9
SLOTS MAPPED TO
REAR DACs
DATA TO I2S D0
PIN 44
DATA TO I2S D1
PIN 43
Not supported in this mode
Not supported in this mode
Not supported in this mode
7 and 8
6 and 9
3 and 4
6 and 9
7 and 8
3 and 4
7 and 8
7 and 8
6 and 9
3 and 4
3 and 4
6 and 9
7 and 8
7 and 8
3 and 4
5 (or 5 and 10 if DLM set)
Not supported in this mode
Not supported in this mode
Not supported in this mode
slave codec register access definitions
Master codec access is exactly as defined for AC’97. For slave codec access, the AC’97 digital controller must
invalidate the tag bits for slots 1 and 2 command address and data (slot 0, bits 14 and 13) and place a nonzero
value (01, 10, or 11) into the codec ID field (slot 0, bits 1 and 0).
Slave codecs disregard the command address and command data (slot 0, bits 14 and 13) tag bits when they
see a two-bit codec ID value (slot 0, bits 1 and 0) that matches their configuration. In a sense, the slave codec
ID field functions as an alternative valid command address (for slave reads and writes) and command data (for
slave writes) tag indicator.
Slave codecs must monitor the frame valid bit and ignore the frame (regardless of the state of the slave codec
ID bits) when it is not valid. AC’97 digital controllers should set the frame valid bit for a frame with a slave register
access, even if no other bits in the output tag slot, except the slave codec ID bits, are set.
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slave codec register access definitions (continued)
Table 7. Slave Codec Register Access Slot 0 – Bit Definitions
OUTPUT TAG SLOt (16 bits)
BIT
DESCRIPTION
15
Frame valid
14
Slot 1 valid command address bit (master codec only)
13
Slot 2 valid command data bit (master codec only)
12–3
2
1–0
Slot 3–12 valid bits as defined by AC’97
Reserved (set to 0)
Two-bit codec ID field (00 reserved for master; 01, 10, 11 indicate slave)
New definitions for slave codec register access
control interface
A digital interface is provided to control the TLV320AIC27 and transfer data to and from it. This serial interface
is compatible with the Intel AC’97, as illustrated in Figure 1.
system information
CD, VIDEO,
AUX, LINEINL/R
MIC1
PCBEEP PHONE
MIC2
22
21
12
13
35
LINEOUTL/R
36
RESET
C54X
/C6X
OR AC’97
COMPLIANT
DIGITAL
CONTROLLER
CHIP
SELECT
BITCLK
SYNC
SDATAIN
SDATAOUT
CID0
CID1
11
6
10
TLV320AIC27
8
39
41
LNLVLOUTL/R
37
MONOOUT
5
45
46
Figure 1. Revision 2.1 Compliant Two-Channel Codec
The main control interface functions are:
D
D
D
14
Control of analog gain and signal paths through the mixer
Bidirectional transfer of ADC and DAC words to and from AC’97 controller
Selection of power down modes
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system information (continued)
TLV320AIC27
SDATAOUT
SDATAOUT
LINEOUTL
Front R data
LINEOUTR
ID=00
Front L data
BITCLK
BITCLK
C54XX/C6X
SDATAIN
SDATAIN
McBSP
SYNC
SYNC
RESET
RESET
O r AC’97 compliant
digital controller
XTLOUT
TLV320AIC27
XTLIN
LINEOUTL
Surround R data
LINEOUTR
ID=10
Surround L data
SDATAOUT
BITCLK
SDATAIN
SYNC
RESET
Figure 2. TLV320AIC27 In a Four-Channel System
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TLV320AIC27
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system information (continued)
TLV320AIC27
C54XX
C6X
McBSP
SDATAOUT
BITCLK
SDATAIN
SDATAOUT
Front R data
LINEOUTR
ID=00
Front L data
BITCLK
SDATAIN
SYNC
SYNC
RESET
RESET
OR AC’97
COMPLIANT
DIGITAL
CONTROLLER
LINEOUTL
XTLOUT
TLV320AIC27
XTLIN
LINEOUTL
Surround R data
LINEOUTR
ID=10
Surround L data
SDATAOUT
BITCLK
SDATAIN
SYNC
RESET
TLV320AIC27
XTLIN
LINEOUTL
Center data
LINEOUTR
ID=11
LFE data
SDATAOUT
BITCLK
SDATAIN
SYNC
RESET
Figure 3. TLV320AIC27 In a Six-Channel System
16
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SLAS253 – MARCH 2000
system information (continued)
CD, VIDEO,
AUX, LINEINL/R
MIC1
PCBEEP PHONE
MIC2
22
21
12
13
35
LINEOUTL/R
Front Data
36
RESET
C54X
/C6X
OR AC’97
COMPLIANT
DIGITAL
CONTROLLER
BITCLK
SYNC
SDATAIN
SDATAOUT
CHIP
SELECT
CID0
CID1
11
39
6
10
LNLVLOUTL/R
Rear Data
41
AIC27
(Quad Mode)
8
MONOOUT
37
5
45
46
43
GPIO
48
[1:3]
Optional For AC-3 Type
Surround Sound (5.1)
I2S Data
LRCLK
BITCLK
SCLK
External
DAC
Surround
Sound
(Center and
LFE Data)
Figure 4. AIC27 In Typical Quad-Mode Application
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SLAS253 – MARCH 2000
system information (continued)
CD, VIDEO,
AUX, LINEINL/R
MIC1
PCBEEP PHONE
MIC2
22
21
12
13
35
LINE_OUT_L/R
Front Data
36
RESET
C54X
/C6X
OR AC’97
COMPLIANT
DIGITAL
CONTROLLER
CHIP
SELECT
BITCLK
SYNC
SDATAIN
SDATAOUT
CID0
CID1
11
39, 41
6
AIC27
(Modem Mode)
10
8
LNLVL_OUT_L/R Tx
13
37
Phone
MONOOUT
5
45
46
2
3
MODE0 = 1
MODE1 = 1
43 44 48
GPIO [1:3]
XTAL
Figure 5. AIC27 In a Typical Modem Application
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Rx
DAA
Modem
Data
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
ac-link digital serial interface protocol
The TLV320AIC27 incorporates a five-pin digital serial interface that links it to the AC’97 controller. The ac link
is a bidirectional, fixed rate, serial PCM digital stream. It handles multiple input and output audio streams, as
well as control register-accesses employing a time-division multiplexed (TDM) scheme. The ac-link architecture
divides each audio frame into 12 outgoing and 12 incoming data streams, each with 20-bit sample resolution.
With a minimum required resolution of 16-bits for the DAC and the ADC, AC’97 can also be implemented with
18 or 20-bit DAC/ADC resolution, given the headroom that the ac-link architecture provides. The TLV320AIC27
provides support for 18-bit operation.
SLOT
NUMBER
0
1
2
3
4
TAG
CMD
ADR
CMD
DATA
PCM
LEFT
PCM
RIGHT
5
6
7
8
9
10
11
12
PCM
LFE
RSRVD
RSRVD
GPIO
CTRL
PCM L
(n+1)
PCM R
(n+1)
PCM C
(n+1)
RSRVD
RSRVD
GPIO
STATUS
SYNC
SDATA_OUT
PCM
PCM
PCM
RSRVD CENTER L SURR R SURR
CODEC ID
SDATA_IN
TAG
STATUS STATUS
ADDR
DATA
PCM
LEFT
PCM
RIGHT
RSRVD
RSRVD
RSRVD
RSRVD
RSRVD
SLOTREQ 3–12
DATA PHASE
TAG PHASE
Figure 6. AC’97 Standard Bidirectional Audio Frame Basic Mode (Two-Channel)
SLOT
NUMBER
0
1
2
3
4
5
6
TAG
CMD
ADR
CMD
DATA
PCM
LEFT
PCM
RIGHT
LINE 1
DAC
7
8
9
10
11
12
PCM
LFE
LINE 2
DAC
RSRVD
GPIO
CTRL
PCM L
(n+1)
PCM R
(n+1)
PCM C
(n+1)
LINE 2
DAC
RSRVD
GPIO
STATUS
SYNC
SDATA_OUT
PCM
PCM
PCM
CENTER L SURR R SURR
CODEC ID
SDATA_IN
TAG
STATUS STATUS
ADDR
DATA
PCM
LEFT
PCM
RIGHT
LINE 1
DAC
RSRVD
RSRVD
RSRVD
RSRVD
SLOTREQ 3–12
DATA PHASE
TAG PHASE
Figure 7. AC’97 Standard Bidirectional Audio Frame Modem Mode
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ac-link digital serial interface protocol (continued)
SLOT
NUMBER
0
1
2
3
4
5
6
TAG
CMD
ADR
CMD
DATA
PCM
LEFT
PCM
RIGHT
LINE 1
DAC
7
8
9
10
11
12
PCM
LFE
LINE 2
DAC
HSET
DAC
IO
CTRL
PCM L
(n+1)
PCM R
(n+1)
PCM C
(n+1)
LINE 2
ADC
HSET
ADC
IO
STATUS
SYNC
PCM
PCM
PCM
CENTER L SURR R SURR
CODEC ID
SDATA_IN
STATUS STATUS
ADDR
DATA
TAG
PCM
LEFT
PCM
RIGHT
LINE 1
DAC
MIC
ADC
RSRVD
RSRVD
RSRVD
SLOTREQ 3–12
Figure 8. AC’97 Standard Bidirectional Audio Frame In Quad Mode
20.8 µS (48 kHz)
TAG PHASE
DATA PHASE
SYNC
12.288 MHz
81.4 nS
BIT_CLK
SDATA_OUT
VALID
FRAME
SLOT(1)
SLOT(2)
SLOT(12)
’0’
’0’
’0’
19
TIME SLOT ’VALID’ BITS
(’1’ = TIME SLOT CONTAINS
VALID PCM DATA)
END OF PREVIOUS
AUDIO FRAME
0
SLOT (1)
19
0
SLOT (2)
19
0
SLOT (3)
19
0
SLOT (12)
Figure 9. AC-Link Serial Interface Protocol Output Frame
The data streams currently defined by the AC’97 specification include:
PCM playback—two output slots
Two-channel composite PCM output stream
PCM record data—two input slots
Two-channel composite PCM input stream
Control—two output slots
Control register write port
Status—two input slots
Control register read port
Optional dedicated microphone input—one input slot
Dedicated microphone input stream in support of stereo AEC
and/or other voice applications
Optional modem line codec output—one output slot
Modem line codec DAC input stream
Optional modem line codec input—one input slot
Modem line codec ADC output stream
The TLV320AIC27 controller signals synchronization of all ac-link data transactions. The TLV320AIC27 drives
the serial bit clock onto the ac link, which the AC’97 controller then qualifies with a synchronization signal to
construct audio frames.
SYNC, fixed at 48 kHz, is derived by dividing down the serial clock (BIT_CLK). BIT_CLK, fixed at 12.288 MHz,
provides the necessary clocking granularity to support 12 20-bit outgoing and incoming time slots. Ac-link serial
data transition occurs on each rising edge of BIT_CLK. The receiver of ac-link data (TLV320AIC27 for outgoing
data and AC’97 controller for incoming data) samples each serial bit on the falling edges of BIT_CLK.
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ac-link digital serial interface protocol (continued)
The ac-link protocol provides for a special 16-bit time slot (slot 0) wherein each bit conveys a valid tag for its
corresponding time slot within the current audio frame. A 1 in a given bit position of slot 0 indicates that the
corresponding time slot within the current audio frame has been assigned to a data stream and contains valid
data. If a slot is tagged invalid, it is the responsibility of the data source (the TLV320AIC27 for the input stream
and the AC’97 controller for the output stream) to fill all bit positions with 0s during that slot’s active time.
SYNC remains high for a total duration of 16 BIT_CLKs at the beginning of each audio frame.
The portion of the audio frame where SYNC is high is defined as the tag phase. The remainder of the audio frame
where SYNC is low is defined as the data phase. Additionally, all clock, sync, and data signals can be halted
to save power. This requires that the TLV320AIC27 be implemented as a static design to allow its register
contents to remain intact when entering a power savings mode.
ac-link audio output frame (SDATA_OUT)
The audio output frame data streams correspond to the multiplexed bundles of all digital output data targeting
the TLV320AIC27’s DAC inputs and control registers. As mentioned earlier, each audio output frame supports
up to 12 20-bit outgoing data time slots. Slot 0 is a reserved time slot containing 16-bits, which are used for
ac-link protocol infrastructure.
The first bit within slot 0 is a global bit (SDATA_OUT slot 0, bit 15) which flags the validity for the entire audio
frame. A valid frame bit equal to 1 indicates that the current audio frame contains at least one time slot of valid
data. The next 12-bit positions sampled by the TLV320AIC27 indicate which of the corresponding 12 time slots
contain valid data.
In this way, data streams of differing sample rates can be transmitted across the ac link at its fixed 48-kHz audio
frame rate. Figure 9 illustrates the time-slot-based ac-link protocol.
AIC27 SAMPLES
SYNC ASSERTION HERE
SYNC
AIC27 SAMPLES
FIRST SDATA_OUT
BIT OF FRAME HERE
BIT_CLK
SDATA_OUT
VALID
FRAME
SLOT (1)
SLOT (2)
END OF PREVIOUS AUDIO FRAME
Figure 10. Start of an Audio Output Frame
A new audio output frame begins with a low-to-high transition of SYNC, as shown in Figure 10. SYNC is
synchronized to the rising edge of BIT_CLK. On the falling edge of BIT_CLK immediately following, the
TLV320AIC27 samples the assertion of SYNC. This falling edge marks the time when both sides of the ac link
are aware of the start of a new audio frame. On the next rising edge of BIT_CLK, AC’97 transitions SDATA_OUT
into the first bit position of slot 0 (valid frame bit). Each new bit position is presented to the ac link on a rising
edge of BIT_CLK, and subsequently sampled by the TLV320AIC27 on the following falling edge of BIT_CLK.
This sequence ensures that data transitions and subsequent sample points for both incoming and outgoing data
streams are time-aligned.
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ac-link audio output frame (SDATA_OUT) (continued)
Baseline AC’97-specified audio functionality should always convert the sample rate to and from a fixed 48 ksps
on the AC’97 controller. This requirement ensures that interoperability between the AC’97 controller and the
TLV320AIC27, among other things, can be assured by definition for baseline specified AC’97 features.
SDATA_OUT’s composite stream is MSB justified (MSB first), with all invalid slot bit positions stuffed with 0s
by the AC’97 controller. In the event that there are less than 20 valid bits within an assigned and valid time slot,
the AC’97 controller always stuffs all trailing invalid bit positions of the 20-bit slot with 0s.
As an example, consider an eight-bit sample stream that is being played out to one of the TLV320AIC27’s DACs.
The first eight-bit positions are presented to the DAC (MSB justified), followed by the next 12-bit positions, which
are stuffed with 0s by the AC’97 controller. This ensures that, regardless of the resolution of the implemented
DAC (16, 18, or 20-bit), no dc biasing is introduced by the least significant bits. When mono audio sample
streams are outputted from the AC’97 controller, it is necessary that both left and right sample-stream time slots
be filled with the same data.
slot 1: command address port
The command port is used to control features and monitor status for the TLV320AIC27 functions including, but
not limited to, mixer settings and power management (refer to the serial interface register map). The control
interface architecture supports up to 64 16-bit read/write registers, addressable on even-byte boundaries. Only
the even registers (00h, 02h, etc.) are valid. Access to odd registers (01h, 03h, etc.) is discouraged (if supported,
they should default to the preceding even-byte boundary—that is, a read from 01h returns the 16-bit contents
of 00h). The TLV320AIC27’s control register file is nonetheless readable as well as writeable to provide more
robust testability.
Audio output frame slot 1 communicates control register address and read/write command information to the
TLV320AIC27.
Command Address Port Bit Assignments
Bit (19)
Read/write command (1 = read, 0 = write)
Bit (18:12)
Control register index (64 16-bit locations, addressed on even byte boundaries)
Bit (11:0)
Reserved (stuffed with 0s)
The first bit (MSB) sampled by the TLV320AIC27 indicates whether the current control transaction is a read or
a write operation. The following seven bit positions communicate the targeted control register address. The
trailing 12 bit positions within the slot are reserved and must be stuffed with 0s by the AC’97 controller.
slot 2: command data port
The command data port is used to deliver 16-bit control register write data in the event that the current command
port operation is a write cycle, as indicated by slot 1, bit 19.
Bit (19:4)
Control register write data (stuffed with 0s if current operation is a read)
Bit (3:0)
Reserved (stuffed with 0s)
If the current command port operation is a read, then the entire time slot must be stuffed with 0s by the AC’97
controller.
slot 3: pcm playback left channel
Audio output frame slot 3 is the composite digital audio left playback stream. In a typical games compatible PC,
this slot is composed of standard PCM (.wav) output samples digitally mixed (in the AC’97 controller or host
processor) with music synthesis output samples. If a sample stream with less than 20 bits of resolution is
transferred, the AC’97 controller must stuff all trailing invalid bit positions within this time slot with 0s.
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ac-link audio output frame (SDATA_OUT) (continued)
slot 4: pcm playback right channel
Audio output frame slot 4 is the composite digital audio right-playback stream. In a typical games-compatible
PC, this slot is composed of standard PCM (.wav) output samples digitally mixed (on the AC’97 controller or
host processor) with music synthesis output samples.
If a sample stream with less than 20 bits of resolution is transferred, the AC’97 controller must stuff all trailing
invalid bit positions within this time slot with 0s.
slot 5: optional modem line1 codec
Audio output frame slot 5 contains the MSB-justified modem line1 DAC input data. This optional AC’97 feature
is supported in the TLV320AIC27, but only in the modem-operation mode (selected with the mode0/1 pins).
When data is written to this location, it is applied to the rear channel DACs if the modem mode is enabled. This
is determined by the AC’97 controller interrogating the TLV320AIC27 vendor ID registers. If modem mode is
disabled, the device appears not to support a modem. If the mode is enabled, the modem support flag is set.
slot 6 to 9: surround sound data
Audio output frame slots 6 to 9 are used to send surround-sound data to the extra DAC channels. These slots
are supported by TLV320AIC27 in Revision 2.1 six-channel mode and quad mode. Note that the data in the
surround-sound slots may be applied to the internal DACs, or sent out onto the GPIO pins as I2S data,
depending upon the mode and ID selected.
slot 10 optional modem line2 codec
Audio output frame slot 10 contains MSB-justified modem line2 DAC input data. This optional AC’97 feature
is supported by TLV320AIC27, but only when register 5Ah DLM (dual line modem) is set.
slot 11 handset DAC
Slot 11 is not supported.
slot 12: GPIO control
Data in this slot is applied to the GPIO pins if they have been enabled via the control registers. Note that only
bits 11, 12, and 13 are supported and all others are ignored.
ac-link audio input frame (SDATA_IN)
20.8 µS (48 kHz)
TAG PHASE
DATA PHASE
SYNC
12.288 MHz
81.4 nS
BIT_CLK
SDATA_IN
CODEC
READY
END OF PREVIOUS
AUDIO FRAME
SLOT(1)
SLOT(2)
SLOT(12)
’0’
’0’
’0’
19
TIME SLOT ’VALID’ BITS
(’1’ = TIME SLOT CONTAINS
VALID PCM DATA)
0
SLOT (1)
19
0
SLOT (2)
19
0
SLOT (3)
19
0
SLOT (12)
Figure 11. AC-Link Audio Input Frame
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ac-link audio input frame (SDATA_IN) (continued)
The audio input frame data streams correspond to the multiplexed bundles of all digital input data targeting the
AC’97 controller. As in the case of audio output frame, each ac-link audio input frame consists of 12 20-bit time
slots.
Slot 0 is a specially reserved time slot containing 16 bits, which are used for ac-link protocol infrastructure. The
first bit in slot 0 is a global bit (SDATA_IN, bit 15) which flags whether the TLV320AIC27 is in the codec-ready
state or not. A codec-ready bit equal to 0 indicates that the TLV320AIC27 is not ready for normal operation. For
example, this is a normal condition following reset, while the TLV320AIC27’s voltage references settle. An
ac-link codec-ready indicator bit equal to 1 indicates that the ac link and the TLV320AIC27 control and status
registers are in fully-operational state. The AC’97 controller must further probe the power-down control/status
register to determine exactly which subsections, if any, are ready.
Prior to any attempts at putting the TLV320AIC27 into operation, the AC’97 controller should poll the first bit in
the audio input frame (SDATA_IN slot 0, bit 15) for an indication that the TLV320AIC27 is codec-ready.
Once the TLV320AIC27 is codec-ready, the next 12 bit positions sampled by the AC’97 controller indicate which
of the corresponding 12 time slots are assigned to input data streams and contain valid data. Figure 11 illustrates
the time-slot-based ac-link protocol.
There are several subsections within the TLV320AIC27 that can independently go busy/ready. It is the
responsibility of the TLV320AIC27 controller to probe more deeply into the TLV320AIC27 register file to
determine which of the TLV320AIC27 subsections are actually ready.
AIC27 SAMPLES
SYNC ASSERTION HERE
SYNC
AC ’97 CONTROLLER
SAMPLES FIRST SDATA_IN
BIT OF FRAME HERE
BIT_CLK
SDATA_IN
CODEC
READY
SLOT (1)
SLOT (2)
END OF PREVIOUS AUDIO FRAME
Figure 12. Start of an Audio Input Frame
A new audio input frame begins with a low-to-high transition of SYNC, as illustrated in Figure 12. SYNC is
synchronous with the rising edge of BIT_CLK. The TLV320AIC27 samples the assertion of SYNC on the next
falling edge of BIT_CLK. This falling edge marks the time when both sides of the ac link are aware of the start
of a new audio frame. The AC’97 controller transitions SDATA_IN into the first bit position of slot 0 (valid frame
bit) on the next rising edge of BIT_CLK. Each new bit position is presented to the ac link on a rising edge of
BIT_CLK, and subsequently sampled by the AC’97 controller on the following falling edge of BIT_CLK. This
sequence ensures that data transitions and subsequent sample points for both incoming and outgoing data
streams are time-aligned.
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ac-link audio input frame (SDATA_IN) (continued)
SDATA_IN’s composite stream is MSB-justified (MSB first), with all invalid bit positions (for assigned and/or
unassigned time slots) stuffed with 0’s by the TLV320AIC27. SDATA_IN is sampled on the falling edges of
BIT_CLK.
slot 1: status address port
The status port is used to monitor the status of the TLV320AIC27 functions,, including, but not limited to, mixer
settings and power management. Audio input frame slot 1 echoes the control register index, for historical
reference, so that the data is returned to slot 2 (assuming that slots 1 and 2 had been tagged valid by the
TLV320AIC27 during slot 0).
Status Address Port Bit Assignments
Bit (19)
Reserved (stuffed with 0s)
Bit (18:12)
Control register index (echo of register index for which data is being returned)
Bit (11:0)
Reserved (stuffed with 0s)
The first bit (MSB) generated by the TLV320AIC27 is always stuffed with a 0. The following 7 bit positions
communicate the associated control register address, and the trailing 12 bit positions are stuffed with 0s by the
TLV320AIC27.
slot 2: status data port
The status data port delivers 16-bit control register read data.
Bit (19:4)
Control register read data
Bit (3:0)
Reserved (stuffed with 0s)
If slot 2 is tagged invalid by the TLV320AIC27, then the entire slot is stuffed with 0s by the TLV320AIC27.
slot 3: PCM record left channel
Audio input frame slot 3 is the left channel output of the TLV320AIC27’s input mux, post-ADC.
The TLV320AIC27’s ADCs can be implemented to support 16, 18, or 20-bit resolutions. The TLV320AIC27
sends out its ADC output data (MSB first), and stuffs any trailing invalid bit positions with 0s to fill out its 20-bit
time slot.
slot 4: PCM record right channel
Audio input frame slot 4 is the right channel output of the TLV320AIC27’s input mux, post-ADC.
The TLV320AIC27’s ADCs can be implemented to support 16, 18, or 20-bit resolutions. The TLV320AIC27
sends out its ADC output data (MSB first), and stuffs any trailing invalid bit positions with 0s to fill out its 20-bit
time slot.
slot 5: optional modem line1 codec
Slot 5 is not supported.
slot 6: optional dedicated microphone record data
Audio input frame slot 6 is an optional (post-ADC) third PCM system input channel available for dedicated use
by a desktop microphone. This optional AC’97 feature is not supported by the TLV320AIC27. This can be
determined by the AC’97 controller interrogating the TLV320AIC27 vendor ID register.
slot 7 to 11: reserved
Audio input frame slots 7 to 12 are reserved for future use and are always stuffed with 0s by the TLV320AIC27.
slot 10: optional modem line2 codec
Slot 10 is not supported.
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ac-link audio input frame (SDATA_IN) (continued)
slot 12:
GPIO functions supported.
ac-link low-power mode
The ac-link signals can be placed in a low-power mode. When the TLV320AIC27’s power-down register 26h
is programmed to the appropriate value, both BIT_CLK and SDATA_IN are brought to and held at a logic-low
voltage level.
BIT_CLK and SDATA_IN transition to low occurs immediately following the decode of the write to the
power-down register 26h with PR4. When the AC’97 controller driver is ready to program the ac link into its
low-power mode, slots 1 and 2 are assumed to be the only valid stream in the audio output frame. At this point
it is assumed that all sources of audio input have also been neutralized.
The AC’97 controller should also drive SYNC and SDATA_OUT low after programming the TLV320AIC27 to
this low-power, halted mode.
Once the TLV320AIC27 has been instructed to halt BIT_CLK, a special wake up protocol must be used to bring
the ac link to the active mode, since normal audio output and input frames can not be communicated in the
absence of BIT_CLK.
waking up the ac link
There are two methods to bring the ac link out of a low-power, halted mode. Regardless of the method, it is the
AC’97 controller that performs the wake-up task.
Ac-link protocol provides for a cold and a warm TLV320AIC27 reset.
The current power-down state would ultimately dictate which form of TLV320AIC27 reset is appropriate. Unless
a cold or register reset (a write to the reset register) is performed, wherein the TLV320AIC27 registers are
initialized to their default values, registers are required to keep state during all power-down modes.
Once powered down, reactivation of the ac link via reassertion of the SYNC signal must not occur for a minimum
of four audio frame times following the frame in which the power down was triggered. When the ac link powers
up, it indicates readiness via the codec-ready bit (input slot 0, bit 15).
cold TLV320AIC27 reset
A cold reset is achieved by asserting RESETB for the minimum specified time. By driving RESETB low,
BIT_CLK, and SDATA_OUT are activated, or reactivated as the case may be, and all the TLV320AIC27 control
registers are initialized to their default power on reset values.
RESETB is an asynchronous TLV320AIC27 input.
warm TLV320AIC27 reset
A warm TLV320AIC27 reset reactivates the ac link without altering the current TLV320AIC27 register values.
A warm reset is signalled by driving SYNC high for a minimum of 1 µS in the absence of BIT_CLK.
Within normal audio frames, SYNC is synchronous to the TLV320AIC27 input. However, in the absence of
BIT_CLK, SYNC is treated as an asynchronous input used in the generation of a warm reset to the
TLV320AIC27. The TLV320AIC27 does not respond to the activation of BIT_CLK until SYNC has been sampled
low again by the TLV320AIC27. This precludes the false detection of a new audio frame.
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serial interface register map description (see Table 23)
The serial interface bits perform control functions described as follows (notice that the register map is fully
specified by the AC’97 specification, and this description is simply repeated below, with optional unsupported
features omitted):
reset register (index 00h)
Writing any value to this register performs a register reset, which causes all registers to revert to their default
values. Reading this register returns the ID code of the part to indicate modem support (not supported by the
TLV320AIC27) and a code for the type of 3D stereo enhancement.
The ID decodes the capabilities of the TLV320AIC27 based on the information in Table 8.
Table 8. Reset Register Function
BIT
FUNCTION
VALUE ON
TLV320AIC27
ID0
Dedicated mic PCM in channel
0
ID1
Modem line codec support
0
ID2
Bass and treble control
0
ID3
Simulated stereo (mono to stereo)
0
ID4
Headphone out support
0
ID5
Loudness (bass boost) support
0
ID6
18-bit DAC resolution
1
ID7
20-bit DAC resolution
0
ID8
18-bit ADC resolution
1
ID9
20-bit ADC resolution
0
SE4...SE0
3D-stereo enhancement technique
11000
Note that the TLV320AIC27 defaults to indicate 18-bit compatibility. However, a control bit can be set in the
vendor-specific registers that changes bits ID6 and ID8 to be 0, indicating a 16-bit device. However, It is unlikely
that this function will be required, as the MSB justification of the ADC and DAC data means that a nominal 18-bit
device should be fully compatible with controllers that only provide 16-bit support. Most PC-type applications
only require 16-bit operation.
play master volume registers (index 02h, 04h and 06h)
These registers manage the output signal volumes. Register 02h controls the stereo master volume (both right
and left channels), register 04h controls the optional stereo headphone out, and register 06h controls the mono
volume output. Each step corresponds to 1.5 dB. The MSB of the register is the mute bit. When this bit is set
to 1, the level for that channel is set to –∞ dB.
ML5 to ML0 are used for left channel level, MR5 to MR0 are used for right channel level, and MM5 to MM0 are
used for mono-out channel level.
Support for the MSB of the volume level is not provided by the TLV320AIC27. If the MSB is written to, then the
TLV320AIC27 detects when that bit is set and sets all four LSBs to 1s. For example, if the driver writes a 1xxxxx,
the TLV320AIC27 interprets that as x11111. It also responds when read with x11111 rather than 1xxxxx, the value
written to it. The driver can use this feature to detect if there is support for the 6th bit.
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play master volume registers (index 02h, 04h and 06h) (continued)
The default value of both the mono and the stereo registers is 8000h (1000 0000 0000 0000), which corresponds
to 0-dB gain with mute on.
Table 9. Volume Register Function
MUTE
Mx4...Mx0
FUNCTION
0
0 0000
0-dB attenuation
0
0 0001
1.5-dB attenuation
0
1 1111
46.5-dB attenuation
1
x xxxx
∞-dB attenuation
master tone control register (index 08h)
This is an optional register for support of tone controls (bass and treble). The TLV320AIC27 does not support
bass and treble, and writing to this register has no effect. Reading results in all don’t care values.
PC beep register (index 0Ah)
This register controls the level of the PC-beep input. Each step corresponds to approximately 3 dB of
attenuation. The register’s MSB is the mute bit. When this bit is set to 1, the level for that channel is set to
–∞ dB.
The TLV320AIC27 defaults to the PC-beep path being muted, so an external speaker should be provided within
the PC to alert the user when power on self-test problems occur.
Table 10. PC-Beep Register Function
MUTE
PV3...PV0
FUNCTION
0
0000
0-dB attenuation
0
1111
45-dB attenuation
1
xxxx
∞-dB attenuation
analog mixer input gain registers (index 0Ch–18h)
These registers control the gain/attenuation of each of the analog inputs. Each step corresponds to
approximately 1.5 dB. The MSB of the register is the mute bit. When this bit is set to 1, the level for that channel
is set to –∞ dB (see Table 11).
register 0Eh (mic volume register)
This register has an extra bit used for a 20-dB boost. When bit 6 is set to 1, the 20-dB boost is on. The default
value is 8008h, which corresponds to 0-dB gain with mute on.
The default value for the mono registers is 8008h, which corresponds to 0-dB gain with mute on. The default
value for stereo registers is 8808h, which corresponds to 0-dB gain with mute on.
Table 11. Mixer Gain Control Register Function
28
MUTE
GX4...GX0
0
00000
12-dB gain
0
01001
0-dB gain
0
11111
–34.5-dB gain
1
xxxxx
–∞-dB gain
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record select control register (index 1Ah)
This register is used to select the record source for right and left independently (see Table 12). The default value
is 0000h, which corresponds to mic in.
Table 12. Record Select Register Function
SR2 TO SR0
RIGHT RECORD SOURCE
SL2 TO SL0
LEFT RECORD SOURCE
0
Mic
0
Mic
1
CD in (R)
1
CD in (L)
2
Video in (R)
2
Video in (L)
3
Aux in (R)
3
Aux in (L)
4
Line in (R)
4
Line in (L)
5
Stereo mix (R)
5
Stereo mix (L)
6
Mono mix
6
Mono mix
7
Phone
7
Phone
record gain registers (index 1Ch and 1Eh)
1Ch is for the stereo input and 1Eh is for the optional special-purpose correlated audio mic channel. Each step
corresponds to 1.5 dB. 22.5 dB corresponds to the range 0F0Fh to 000Fh. The MSB of the register is the mute
bit. When this bit is set to 1, the level for that channel(s) is set to –∞ dB.
The default value is 8000h, which corresponds to 0-dB gain with mute on.
Table 13. Record Gain Register Function
MUTE
GX3...GX0
FUNCTION
0
1111
22.5-dB gain
0
0000
0-dB gain
1
xxxxx
–∞-dB gain
general-purpose register (index 20h)
This register is used to control several miscellaneous functions of the TLV320AIC27.
Table 14 shows a summary of each bit and its function. Only the MIX, MS, and LPBK bits are supported by the
TLV320AIC27. The MS bit controls the mic selector. The LPBK bit enables loopback of the ADC output to the
DAC input without involving the ac link, allowing for full system-performance measurements. The function
default value is 0000h which is all off.
Table 14. General Purpose Register Function
BIT
POP
FUNCTION
PCM out path and mute, 0 = pre-3D, 1 = post-3D
TLV320AIC27
SUPPORT
Yes, but fixed at 1
ST
Simulated stereo enhancement on/off, 1 = on
No
3D
3D stereo enhancement on/off, 1 = on
Yes
LD
Loudness (bass boost) on/off, 1 = on
No
LLBK
Local loop back—for modem, line codec
No
RLBK
Remote loop back—for modem, line codec
No
MIX
Mono output select 0 = Mix, 1 = Mic
Yes
MS
Mic select 0 = Mic1, 1 = Mic2
Yes
ADC/DAC/ loopback mode
Yes
LPBK
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3D control register (index 22h)
This register is used to control the center and/or depth of the 3D stereo-enhancement function built into the
AC’97 component. Only the depth bits, DP0–3 have effect in the TLV320AIC27.
DP3...DP0
DEPTH
0
0%
1
–
8
Typical value
–
15
100%
reserved register (index 24h)
Not supported by the TLV320AIC27.
power-down control/status register (index 26h)
This read/write register is used to program the power-down states and to monitor subsystem readiness. The
lower half of this register is read-only status, a 1 indicating that the subsection is ready. Ready is defined as the
subsection being able to perform in its nominal state. When this register is written, the bit values that come in
on the ac link have no effect on read only bits 0 to 7.
An ac-link codec-ready indicator bit (SDATA_IN slot 0, bit 15) equal to 1 it indicates that the ac link and the
TLV320AIC27 control and status registers are in a fully operational state. The AC’97 controller must further
probe this power-down control/status register to determine exactly which subsections, if any, are ready.
Table 15. Power-Down Status Register Function
READ BIT
FUNCTION
REF
VREFs up to nominal level
ANL
Analog mixers, etc., ready
DAC
DAC section ready to accept data
ADC
ADC section ready to transmit data
The power-down modes are as follows. The first three bits are to be used individually rather than in combination
with each other. The last bit PR3 can be used in combination with PR2 or by itself. PR0 and PR1 control the
PCM ADCs and DACs only. PR6 is not supported by the TLV320AIC27.
Table 16. Power-Down Control Register Function
WRITE BIT
PR0
PCM in ADCs and input Mux power down
PR1
PCM out DACs power down
PR2
Analog mixer power down (VREF still on)
PR3
Analog mixer power down (VREF off)
PR4
Digital interface (ac link) power down (external clock off)
PR5
Internal clock disable
PR6
HP amp power down – not supported
EAPD
30
FUNCTION
External amplifier power down
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power-down control/status register (index 26h) (continued)
PR0 = 1
NORMAL
PR1 = 1
ADCs OFF
PR0
PR0 = 0 AND
ADC = 1
PR2 = 1
DACs OFF
PR1
PR1 = 0 AND
DAC = 1
PR4 = 1
ANALOGUE
OFF PR2 OR
PR3
PR2 = 0 AND
ANL = 1
READY = 1
DIGITAL I/F
OFF PR4
SHUT OFF
CODA LINK
WARM
RESET
COLD RESET
DEFAULT
Figure 13. An Example of the TLV320AIC27 Power-Down/Power-Up Flow
Figure 13 illustrates one example of a procedure to perform a complete power down of the TLV320AIC27. From
normal operation, sequential writes to the power-down register are performed to power down the TLV320AIC27
one piece at a time. After everything has been shut off (PR0 to PR3 set), a final write (of PR4) can be executed
to shut down the TLV320AIC27’s digital interface (ac link).
The part remains in sleep mode with all its registers holding their static values. To wake up the TLV320AIC27,
the AC’97 controller sends a pulse on the sync line issuing a warm reset. This restarts the TLV320AIC27’s digital
interface (resetting PR4 to 0). The TLV320AIC27 can also be woken up with a cold reset. A cold reset causes
a loss of values to the registers, as it sets them to their default states. When a section is powered back on, the
power-down control/status register index 26h should be read to verify that the section is ready (that is, stable)
before attempting any operation that requires it.
Alternatively, if RESETB is held low, all PR bits are held set so the device stays powered off until RESETB is
taken high again.
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power-down control/status register (index 26h) (continued)
PR0 = 1
NORMAL
PR1 = 1
ADCs OFF
PR0
PR0 = 0 AND
ADC = 1
PR2 = 1
DACs OFF
PR1
PR1 = 0 AND
DAC = 1
PR4 = 1
ANALOG
OFF PR2 OR
PR3
PR2 = 0 AND
ANL = 1
READY = 1
DIGITAL I/F
OFF PR4
SHUT OFF
CODA LINK
WARM
RESET
COLD RESET
DEFAULT
Figure 14. The TLV320AIC27 Power-Down/Flow With Analog Still Alive
Figure 14 illustrates a state where all the mixers should work with the static volume settings contained in their
associated registers. This is used when the user is playing a CD (or external LINEIN source) through the
TLV320AIC27 to the speakers, but has most of the system in low-power mode. The procedure for this follows
the previous procedure, except that the analog mixer is never shut down.
Note that PR5 is required to be set in order to go into ultimate low-power mode, which turns off the oscillator
circuit. Asserting SYNC resets the PR5 bit and restarts the oscillator in the same way as the ac link is restarted.
Also, when RESETB pin is asserted low, all PR bits are overridden and the entire device is powered off to
ultralow-power state for as long as RESETB = low. When RESETB is released the device is reset (all active)
and powered up.
vendor-reserved registers (index 5Ah to 7Ah)
These vendor-specific registers are reserved for future use. Do not write to these registers unless the vendor
ID register has been checked first to ensure that the driver knows the source of the AC’97 component. Values
stored in this register are intended to provide test modes for use by the manufacturer.
revision 2.1 registers (index 28h to 58h)
The use of these registers is specified in Revision 2.1 of the AC’97 specification and have the following functions
on the TLV320AIC27:
register 28h – extended audio ID
The extended audio ID register is a read-only register that identifies which extended audio features are
supported (in addition to the original AC’97 features identified by reading the reset register at index 00h). A
nonzero value indicates the feature is supported. The indication of support for six-channel surround sound
changes depending on whether the TLV320AIC27 is configured in mode 00 or otherwise.
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register 28h – extended audio ID (continued)
Table 17. Extended Audio ID Register
DATA BIT
ANY MODE BUT 10
MODE 10
VRA
Variable rate audio support
FUNCTION
1
1
DRA
Double rate audio support
0
0
VRM
Variable rate mic ADC support
0
0
1 when ID = 11 or I2S = 1
1 when ID = 11 or I2S = 1
CDAC
Center DAC support
SDAC
Surround DAC support
0 (unless I2S = 1)
0 (unless I2S = 1)
LDAC
LFE DAC support
0 (unless I2S = 1)
AMAP
Slot to front DAC mapping support
1
1
ID1
Codec configuration – pin 45 value
Inverse of level at pin 45
Inverse of level at pin 45
ID0
Codec configuration – pin 46 value
Inverse of level at pin 46
Inverse of level at pin 46
1
register 2Ah – extended audio status and control register
The extended audio status and control register is a read/write register that provides status and control of the
extended audio features.
Table 18. Extended Audio Status and Control Register
DATA BIT
FUNCTION
READ/WRITE
TLV320AIC27
SUPPORT
VRA
Enables variable rate audio mode
Read/write
Yes
DRA
Enable double rate audio mode
Read/write
No
VRM
Enables variable rate mic ADC
Read/write
No
CDAC
Indicates center DAC ready
Read
Yes
SDAC
Indicates surround DAC ready
Read
Yes
LDAC
Indicates LFE DAC ready
Read
Yes
MADC
Indicates mic ADC ready
Read
No
PRI
Set to turn off center DAC
Read/write
Enable only
PRJ
Set to turn off surround DACs
Read/write
Enable only
PRK
Set to turn off LFE DACs
Read/write
Enable only
PRL
Set to turn off mic ADC
Read/write
No
register 2Ch to 32h – audio sample rate control registers
These registers are read/write registers—writing to this registers is done to select alternative sample rates for
the audio PCM converters. The default rate is 48 ksps. Note that only Revision 2.1-recommended rates are
supported by the TLV320AIC27; selection of any other unsupported rates causes the rate to default to the
nearest supported rate, and the supported rate value to be latched and therefore, read back.
Register 2Ch is the front DAC rate register, but it is also used for center channel data rate.
I2S mode only supports 48 ksps rates, not variable rates.
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registers 36h and 38h—six-channel volume control
These read/write registers control the output volume of the four optional PCM channels. Note that since the
TLV320AIC27 only supports four internal DACs, depending upon which ID has been selected via the CID pins
45 and 46, these registers may or may not have effect. The fields behave the same as the master volume control
register, which offers attenuation but no gain. If gain is required, then the PCM DAC mixer PGAs corresponding
to each DAC should be used.
If quad mode is selected and ID = 10 or 11, then either 36h or 38h controls the level of the rear DAC outputs
onto the line level pins 39 and 41. Surround data which is mapped from the surround data slots out onto the
GPIO pins as I2S data may not have its level adjusted. The mute bit will, however, mute the data to all 0s.
modem registers (index 3Ch and 56h)
The contents of these registers control modem function.
register 3Ch – extended modem ID
The extended modem ID is a read/write register that primarily identifies the enhanced codecs modem AFE
capabilities. The default value depends on features and hardware configuration. Writing any value to this
register performs a warm modem AFE reset (register range 3C–56h), including GPIO (register range 4C–54h).
The warm reset causes all affected registers to revert to their default values. Note that for AMC ’97 parts, the
audio and modem AFE should be logically independent (writes to register 0h reset audio only).
D
D
D
D
D
D
LIN1 = 1 indicates that the first line is supported – set when TLV320AIC27 is in modem mode1 = 1
LIN2 = 1 indicates that the second line is supported – supported on TLV320AIC27 when DLM is set
HSET = 1 indicates that the handset DAC/ADC is supported – not supported on TLV320AIC27
CID1 = 1 indicates that caller ID decode for line1 is supported – not supported on TLV320AIC27
CID2 = 1 indicates that caller ID decode for line2 is supported – not supported on TLV320AIC27
ID1, ID0 is a two-bit field which indicates the codec configuration: primary is 00; secondary is 01, 10, or 11
register 3Eh – extended-modem status control
The extended-modem status and control register functions similarly to the original AC’97 power-down
control/status register located at index 26h. The (A)MC ’97 codec must restrict modem and handset
power-down control/status to this register, since all of the functions are provided here. Therefore, the (A)MC’97
codec (and AC’97 digital controller, of course) must ignore bits MDM and PR7 in register 26h and use what is
included here. When the GPIO section is powered down all outputs must be 3-state and input slot 12 should
be marked invalid when the ac link is active. When slot 12 is invalid, register 54h (GPIO pin status register)
reports 0s. In addition, the codec should force SDATA_IN slot 12 to all 0s. Bits 7 to 0 are read-only, and 1
indicates modem AFE subsystem readiness
D
D
D
D
D
D
D
D
34
GPIO = 1 indicates GPIO-ready
MREF = 1 indicates modem VREFs up to nominal level
ADC1 = 1 indicates modem line1 ADC ready
DAC1 = 1 indicates modem line1 DAC ready
ADC2 = 1 indicates modem line2 ADC ready – supported on TLV320AIC27 when DLM is set
DAC2 = 1 indicates modem line2 DAC ready –supported on TLV320AIC27 when DLM is set
HADC = 1 indicates handset ADC ready – not supported on TLV320AIC27
HDAC = 1 indicates handset DAC ready – not supported on TLV320AIC27
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register 3Eh – extended-modem status control (continued)
Bits 15 to 8 are read/write and control modem AFE subsystem power down. The TLV320AIC27 power-up/down
functions are entirely controlled from register 26h. However, the following registers are aliased onto the
appropriate control bits in registers 26h.
D
D
D
D
D
D
D
D
PRA = 1 indicates GPIO power down
PRB = 1 indicates modem VREF off – no separate modem VREF on TLV320AIC27, aliases from PR3
PRC = 1 indicates modem line1 ADC off – aliases from PR0
PRD = 1 indicates modem line1 DAC off – aliases from PR1
PRE = 1 indicates modem line2 ADC off – not supported on TLV320AIC27
PRF = 1 indicates modem line2 DAC off – not supported on TLV320AIC27
PRG = 1 indicates handset ADC off – not supported on TLV320AIC27
PRH = 1 indicates handset DAC off – not supported on TLV320AIC27
Bits 7 to 0 are read-only: a 1 indicates modem AFE subsystem readiness. Bits 15 to 8 are read/write and control
modem AFE subsystem power down. Writing ENABLES (0) to the above aliased PR bits is allowed, and will
write enable to the appropriate PRN bit. However, writing DISABLES (1) is not allowed.
register 40h – line1 ADC/DAC sample rate
The read/write register 40h controls the modem DAC and ADC sample rates. This register is only functional if
modem mode1 = 1 is selected from pins 30 and 40. The ADC only uses this sample rate if the input to the record
mux is also selected, as the right ADC in register 1Ah is PHONE. Note that only the recommended sample rates
are supported. If alternative sample rates are selected, the rate defaults to the nearest sample rate supported,
and that value is read back.
register 46h to 48h – line1 and line2 ADC level
These registers are not supported in TLV320AIC27. Register 04h is used to control TX modem level.
register 56h – miscellaneous modem AFE status/control
This read/write register defines the loop-back modes available for the modem line and handset ADCs/DACs
described in the Intel specification. Line1 ADC loopback-mode 001 L1B0 is supported.
GPIO function
Note that only GPIO pins 11 to 13 are supported. These pins are available to the user, unless used for I2S mode.
The GPIO mode overrides the I2S function.
register 4Ch – GPIO pin-configuration register
The GPIO pin configuration register is a read/write register that specifies whether a GPIO pin is configured for
input (1), or for output (0), and is accessed via the standard slots 1 and 2 command address/data protocols.
If a GPIO pin is implemented, the respective GCx bit should be readable/writeable and set to 1. If a GPIO is not
implemented, then the respective GCx bit is read-only and set to 0. This informs the software how many GPIO
pins have been implemented. It is up to the AC’97 digital controller to send the desired GPIO pin value over
output slot 12 in the outgoing stream of the ac link before configuring any of these bits for output. The default
value of this register (3800h) after cold reset or register reset is all pins configured as inputs.
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SLAS253 – MARCH 2000
register 4Eh – GPIO pin polarity/type
The GPIO pin polarity/type is a read/write register that defines the GPIO input polarity (0 = low, 1 = high active)
when a GPIO pin is configured as an input. It defines GPIO output type (1 = CMOS, 0 = open drain) when a GPIO
pin is configured as an output.
The default value of this register (FFFFh) after cold or register reset is all pins active high. Nonimplemented
GPIO pins always return 1s.
register 50h – GPIO pin sticky control
The GPIO pin sticky control is a read/write register that defines GPIO input type (0 = nonsticky, 1 = sticky) when
a GPIO pin is configured as an input. GPIO inputs configured as sticky are cleared by writing a 0 to the
corresponding bit of the GPIO pin status register 54h (see below), or by resetting it.
The default value of this register (0000h) after a cold or register reset. Unimplemented GPIO pins always return
0s. Sticky is defined as edge-sensitive, nonsticky is defined as level-sensitive.
register 52h – GPIO pin wake-up control
The GPIO wake-up pin is a read/write register that provides a mask for determining if an input GPIO change
will generate a wake up or a GPIO_INT (0 = no, 1 = yes). When the ac link is powered down (register 26h
PR4 = 1 for primary codecs), a wake-up event triggers the assertion of SDATA_IN. When the ac link is powered
up, a wake-up event will appear as GPIO_INT = 1 on bit 0 of input slot 12. GPIO_INT is also flagged when the
link is active.
An ac-link wake-up interrupt is defined as a 0 to 1 transition of SDATA_IN when the ac link is powered down
(register 26h PR4 = 1). The GPIO bits that have been programmed as inputs (sticky and wake-up) will cause
an ac-link wake-up event (transition of SDATA_IN from 0 to 1) upon either (high-to-low) or (low-to-high) transition
(depending on pin polarity) only if the ac link was powered down.
The default value of this register (0000h) after a cold or register reset is all 0s, specifying no wake-up event.
Nonimplemented GPIO pins always return 0s.
register 54h – GPIO pin status
The GPIO status is a read/write register that reflects the state of all GPIO pins (inputs and outputs) on slot 12.
The value of all GPIO pin inputs and outputs comes in from the codec on slot 12 at every frame. This value is
also available for reading as GPIO pin status via the standard slots 1 and 2 command address/data protocols.
GPIO inputs configured as sticky are cleared by writing a 0 to the corresponding bit of register 54h.
Bits corresponding to unimplemented GPIO pins should be forced to zero in this register and input slot 12. GPIO
bits that have been programmed as inputs and sticky, upon either (high-to-low) or (low-to-high) transition,
depending on pin polarity, will cause the individual GPIO bit to be asserted to 1 and remain asserted until a write
of 0 to that bit. The normal way to set the desired value of a GPIO output pin is to set the control bit in output
slot 12.
If configured as an input, the default value of this register after a cold or register reset is always the state of the
GPIO pin.
register 56h – miscellaneous modem AFE status/control
Not supported in this mode.
vendor reserved registers (index 5Ah and 7Ah)
These registers are vendor-specific. Do not write to these registers unless the vendor ID register has been
checked first to ensure that the driver knows the source of the AC‘97 component. Values stored in this register
are used to provide vendor-specific modes for the manufacturer.
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vendor reserved registers (index 5Ah and 7Ah) (continued)
Table 19. Vendor Register 5Ah Bit Allocation and Default States
BIT
NAME
DEFAULT
ACTION WHEN SET TO 1
Test-only bits – not normal use
AEV
ADC evaluation
0
ADC evaluation mode select bit – do not use
BB
BIASBOOST
0
Increases analog bias currents by 50%
TRM
TSTRECMUX
0
Enables record mux test mode. RECMUX outputs summed into the front and rear DAC output path.
HIC
HALFICONV
0
Halves bias current to the converters
HIM
MALFIMIX
0
Halves bias current to the mixer block
DDS
Dither disable
0
Disables ADC and DAC digital dither – do not use
RTS
RAM test mode
0
Digital test mode – do not use
DFT
DAC FIT test
0
Digital test mode – do not use
AFT
ADC FIR test
0
Digital test mode – do not use
DTS
DAC test
0
Digital test mode – do not use
ATS
ADC test
0
Digital test mode – do not use
AND
ADC no DAC
0
Select stereo mix into ADC as having no DAC signal
R2S
I2S
Rev 2.1 switch
I2S enable
0
0
Closes Rev 2.1 switch when set (see Figure 15)
Enables I2S data and clock onto GPIO pins 43, 44, 48
DLM
Dual line modem
0
Selects support for line2 DAC and ADC slots
AMD
Automute disable
0
Disables automute function on the front and rear DACs
User bits
vendor-specific gain control registers – (index 70h to 74h)
These three registers control the gain and mute functions applied to the front and rear mixer paths, and the rear
channel DAC gains. These PGAs are not accommodated in the Intel specification, but are required in order to
build a flexible quad surround sound device. The function is as per the other mixer PGAs. However, the default
value of the register changes depending upon the mode of operation of the device is, as shown in Table 20.
Table 20. Vendor-Specific PGA Default Values, Vendor ID Registers (Index 7Ch to 7Eh)
DEFAULT VALUE FOR REGISTER
MODE
REAR DAC – REG 70H
FRONT MIXER – REG 72H
REAR MIXER – REG 74H
REV 2.1
SWITCH
Rev 2.1 (00)
8808
0808
8808
Closed
Rev 2.1 six-channel (01)
8808
0808
8808
Closed
Quad (10)
8808
0808
0808
Open
Modem (11)
0808
0808
0808
Open
This register is use for specific vendor identification, if so desired. The ID method is Microsoft’s plug and play
vendor ID code. The first character of that ID is F7 to F0, the second character is S7 to S0, and the third character
is T7 to T0. These three characters are ASCII encoded. The REV7 to REV0 field is for the vendor revision
number. For the TLV320AIC27, the vendor ID is set to TXN3 if MODE1 = 0, and to TXN4 if MODE1 = 1.
Microsoft is a registered trademark of Microsoft Corporation
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operational mode description
operational modes
The TLV320AIC27 has four modes of operation: two-channel, six-channel I2S, quad, and modem. The mode
is determined by pins 30 and 40, as shown in Table 21.
Table 21. Modes of Operation
MODE1
(MODE40)
MODE0
(PIN30)
OPERATIONAL
MODE
RESULTING DEVICE BEHAVIOR
0
0
0
Basic
Two-channel mode codec
1
Six-channel I2S
Quad
Six-channel mode codec
Quad DAC mode (with I2S six-channel support)
1
0
1
1
Modem
Modem DAC mode
basic mode
In basic mode, the TLV320AIC27 comprises a stereo 18-bit codec, (that is, two ADCs and two DACs) plus a
comprehensive analog mixer with four sets of stereo inputs, plus one phone input, two microphone inputs, and
one PC-beep input. The TLV320AIC27 supports 18-bit resolution within the DAC and ADC functions. However,
the AC’97 serial interface specification allows any word length up to 20-bits to be written to, or read from the
AC’97 codec. These words are MSB-justified, and any unused LSBs simply defaults to 0. It is anticipated that
16-bit words will be used in most applications. Therefore, for the DAC, 16-bit words will be downloaded into the
codec from the controller, along with padding of 0s to make the 16-bit word up to 20-bit in length. In this case,
the TLV320AIC27 processes the 16-bit word along with 0 padding bits in the two LSB locations (to make it
18-bit). At the ADC output, the TLV320AIC27 provides an 18-bit word, again with 0s in the two LSB locations
(20-bit). The AC’97 controller then ignores the four LSBs of the 20-bit word. When the TLV320AIC27 is
interrogated, its response indicates it is an 18-bit device.
An internally generated midrail reference is provided at pin CAP2 which is used as the chip reference. This pin
should be heavily decoupled.
basic mode features
D
D
D
D
D
D
Vendor ID reads back as TXN3
Two channels of ADC and DAC conversion provided, with all recommended audio and modem sample rates
supported via the audio sample-rate registers 2Ch and 32h
Master/slave ID0/1 supported
Headphone/line level outputs (duplicating the main outputs) supported, with gain control from register 04h
3D stereo enhanced sound supported
Master volume control register maps to the location dependant on selected ID: (ID 00 or 01 uses master
volume at register 02h, ID 10 uses 38h (surround volume), and ID 11 uses 36h (LFE, center volume)
quad mode
The TLV320AIC27 codec comprises two channels of ADC and four channels of DAC. This enables a
four-channel surround sound solution to be implemented (quad mode). A symmetric mixer is provided which
allows analog signals such as CD inputs to be mixed into both front and rear channel paths simultaneously.
Alternatively, the device can be configured in six-channel I2S mode. In this mode the device uses three GPIO
pins to output rear channel and center and LFE data in I2S format to an external DAC to build a full six-channel
surround sound solution.
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quad mode (continued)
The two additional DAC channels are enabled in this mode, using the line level output pins 39 and 41 as outputs.
An additional mixer block in this path allows the analog mix, excluding the front DAC channels, to be summed
into the rear channel mix. Additional gain controls (PGAs) are provided to allow adjustment of front and rear mix
levels separately (registers 72h and 74h) prior to summing the analog mix to these channels. The rear channel
DACs are also gain-adjustable using register 70h. This function duplicates the features provided for the front
DAC channel (gain range, step size, etc.).
quad mode features
D
D
D
D
D
D
D
D
D
D
D
D
Vendor ID reads back TXN4
All six audio channels flagged as supported (if I2S enable bit is set)
Headphone channel flagged as not supported (bit ID4 in register 00h)
Four channels of DAC and two channels of ADC conversion available, with all recommended audio and
modem sample rates supported via the audio sample-rate registers 2Ch (front channels, slots 3 and 4), 2Eh
(rear channels; slots 7 and 8), and 32h (ADCs). Note that if ID is selected as 11, register 30h is used for
sample rate of LFE channel, slot 9.
GPIO capability supporting bits 11 to 13 flagged as supported
Master/slave ID0/1 supported, with automatic remapping of the rear or LFE/center DAC slot data onto the
rear DACs when ID 10 or 11 are selected (normally surround slots are mapped onto the rear DACs).
LFE and center channel data, plus a duplicate of the rear channel data, is sent from the GPIO pins in I2S
format, at 48 ksps rate (no variable rates supported by the I2S outputs).
Headphone/line level outputs used to output the rear DAC and mixer channel, with volume controlled from
register 38h.
3D stereo enhancement supported
Master volume control register maps to the location dependant on selected ID: ID 00 or 01 uses master
volume at register 02h, ID 10 uses 38h (surround volume), and ID 11 uses 36h (LFE, center volume). In
ID11 bits 7 and 15 act as left and right mute.
DAC mute (reg18h) automatically demuted when ID is 1x, that is, used as surround DAC or LFE/center
when surround or LFE/center master volume is demuted.
In order to achieve the above functionality, the following changes to the Revision 2.1 compliant defaults are
required:
•
•
•
•
•
Revision 2.1 legacy compliance switch is opened (can be closed using REV2SW bit in register 5Ah)
Rear channel mixer PGA default is now not muted, 0-dB gain (same as front channel mixer)
LNLVL pin volume control is now controlled from 02h, unless ID = IO when volume control is from 38h
Rear DAC level set by register 70h, default is 0-dB not-muted
Front mixer and rear mixer gains set in registers 72h and 74h
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six-channel I2S mode
In this mode, the device now has six-channel support and GPIO capability. Rear and LFE center DAC data is
mapped onto the GPIO output pins as I2S data when these data slots are tagged as valid. The I2S enable bit
is set in register 5Ah. Enabling of I2S overrides the GPIO function.
six-channel I 2S mode features
D
D
D
D
D
D
D
D
D
Vendor ID reads back as TXN3
ADC and DAC conversion channels provided
Rear and LFE/center DAC slots flagged as supported in extended audio capability register 28h
GPIO capability supporting bits 11–13 flagged as supported
Master/slave ID0/1 supported
Surround audio data not sent to the DACs is sent from the GPIO pins in I2S format, at 48 ksps rate (no
variable rates supported by the I2S outputs).
Headphone/line level outputs duplicating the main outputs supported, with gain control from register 04h.
3D stereo enhanced sound supported
Master volume control register maps to the location dependant on selected ID: ID 00 or 01 uses master
volume at register 02h, ID 10 uses 38h (surround volume), and ID 11 uses 36h (LFE, center volume). In
this case, bits 7 and 15 act as left and right mute.
GPIO pins and I 2S
The AC’97 Revision 2.1 specification has provisions for up to 16 programmable IO pins. Within the 48-pin TQFP
package used, provision has been made for three pins to be used as GPIO pins. These pins (numbers 43, 44,
48) are also used as I2S output pins to support multichannel operation.
When pins 43, 44, and 48 are used as GPIO pins, they are mapped onto bits 11, 12, and 13, respectively, in
the ac-link slot 12. These optional locations may be configured in any way—as inputs or outputs, as supporting
interrupt operation, etc., offering maximum flexibility to the user. The appropriate GPIO control registers are
supported to control these pins.
When pins 43, 44, and 48 are used as I2S pins, pin 48 becomes the shared LRCLK with frequency fixed at 48
kHz, and pins 43 and 44 become the output data clocked out at the BITCLK rate. Thus, to connect an external
DAC, configure it in I2S mode as follows:
•
•
•
•
•
Connect BITCLK signal from the TLV320AIC27 to SCLK on the DAC.
Connect BITCLK signal from the TLV320AIC27 to SCLK on the DAC.
Connect BITCLK from the AC’97 to BCLK on the DAC.
Connect pin 48 from the TLV320AIC27 to LRCLK on the DAC.
Connect one of the two data pins, 43 or 44, on TLV320AIC27 to the SDATA pin on the DAC.
Note that the DAC must support serial interface data rates of up to 12.5 MHz. This is supported by Texas
Instruments DAC product line.
I2S is enabled when GPIO is not enabled (GPIO Bit 0 is enabled in register 3Eh) and vendor-specific I2S (bit
7) in register 5Ah is set.
Table 22 shows the connections to a typical I2S compatible stereo DAC.
40
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GPIO pins and I 2S (continued)
Table 22. Connection to External I2S DACs
I2S DAC CONNECTION
TLV320AIC27 CONNECTION
BITCLK
SCLK
BITCLK
BLCK
Pin 48 – GPIO3
LRCLK
Pin 43 – GPIO1 (LFE/center data in ID00)
SDATA on external DAC
Pin 44 – GPIO2 (surround data in ID00)
SDATA on other external DAC
FORMAT pin – connect for I2S mode
DEEMPH (if provided) – disable
Configuration of these pins as GPIO is explained in the control interface description.
modem mode
In modem mode, the modem Tx data is mapped onto the rear DACs. Rear DAC sample rates are set by the
modem’s Tx sample rate register 40h. Extended modem capability register 3Ch indicates that line1 is
supported.
modem mode features
D
D
D
D
D
D
D
D
D
D
D
D
D
Vendor ID reads back TXN4
Headphone channel flagged as not supported (bit ID4 in register 00h)
Four channels of DAC and two of ADC conversion available, with all recommended audio and modem
sample rates supported via the audio sample rate registers 2Ch (front DACs), 40h (rear DACs), and 32h
(ADCs in audio mode).
ADC samples are outputted onto both audio slots 3 and 4 and also onto line2/1 slots 10 and 5, respectively.
Line1 Tx modem data is mapped onto the rear DACs as data and as inverted data, so that the pair of rear
DACs produce a differential Tx modem data output.
Right audio ADC changes to use line1 sample rate 40h when input mix selects PHONE as its IP.
The additional vendor-specific mode DLM is available via bit DLM in register 5Ah. Setting this bit provides
support for line2 as well as line1 slots. Rear DACs are mapped onto line1 and line2 Tx modem data slots,
and ADC left and right outputs are mapped both onto normal audio slots 3 and 4 and also onto the line1
and line2 Rx modem data slots. Modem rate register 40h is used for both DACs, and the ADC’s use their
normal sample rate registers (that is, audio registers), unless right channel is selected as PHONE, in which
case they too use register 40h.
If DLM bit is set in register 5Ah, then line1 Tx data is mapped onto the rear left DAC, and Line2 Tx data is
mapped onto the rear right DAC. Both rear DACs use the same sample rate from register 40h (if 42h is
written to, 40h will be updated instead).
The left ADC always uses the normal ADC audio rate register, except when RPHONE is selected in DLM
mode, in which case it uses 40h.
GPIO capability supporting GPIO (11 to 13) flagged as supported
Master/slave ID0/1 supported, with automatic remapping of the rear or LFE/center DAC slot data onto the
front DACs when ID 10 or 11 is selected.
Headphone/line level output pins 39 and 41 used to output the rear DAC signals, with volume controlled
from register 04h. Rear mixer PGA is fixed in mute condition.
3D-stereo enhancement supported
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modem mode features (continued)
D
D
D
D
D
Master volume control register maps to a location dependant on selected ID: ID 00 or 01 uses master
volume at register 02h, ID 10 uses 38h (surround volume), and ID 11 uses 36h (LFE, center volume). In
ID11, bits 7 and 15 act as left and right mute.
Front DAC mute (reg18h) automatically demuted when ID is 1x. That is, it is used as surround DAC or
LFE/center when surround or LFE/center master volume is demuted.
Rear DAC mute (reg70h) automatically demuted when 04h volume is demuted
ADCs always use record level from register 1Ch
In order to achieve the above functionality, the following changes to Rev 2.1 compliant, or quad mode,
defaults are made:
•
•
•
•
Rev 2.1 legacy compliance switch is opened (can be closed using REV2SW bit in register 5Ah)
Rear channel mixer PGA default is now permanently muted (it is unlikely that user will want to send the
analog mix output onto the Tx modem line output)
Tx modem level at the LNLVL pins still controlled from 04h rather than 46h or 48h (which would normally
be the modem ADC and DAC level-control registers)
Rx ADC input levels are still controlled from the normal ADC record level register 1Ch (rather than from
46h or 48h, due to the difficulty in reallocating left and right channel gain controls into two different
registers).
The AC’97 Rev 2.1 specification allows for provision of up to 16 programmable IO pins. Within the 48-pin TQFP
package used, provision has been made for three pins to be used as GPIO pins. These pins (numbers 43, 44,
and 48) are also used as I2S output pins to support multichannel operation.
When used as GPIO pins, pins 43, 44, and 48 are mapped onto bits 11, 12, and 13 in the ac-link slot 12. These
optional locations may be configured in any way: as inputs or outputs, as supporting interrupt operation, etc.,
offering maximum flexibility to the user. The appropriate GPIO control registers are supported to control these
pins.
Configuration of these pins as GPIO is explained in the control interface description.
modem registers (index 3Ch and 56h)
The contents of these registers control modem function
register 3Ch – extended modem ID
The extended modem ID is a read/write register that primarily identifies the enhanced codecs modem AFE
capabilities. The default value will depend on features and hardware configuration. Writing any value to this
register performs a warm modem AFE reset (register range 3C–56h), including GPIO (register range 4C–54h).
The warm reset causes all affected registers to revert to their default values. Note: for AMC ’97 parts the audio
and modem AFE should be logically independent (writes to register 0h resets audio only).
D
D
D
D
D
D
42
LIN1 = 1 indicates first line is supported – set when TLV320AIC27 is in Modem mode1 = 1
LIN2 = 1 indicates second line is supported – supported on TLV320AIC27 when DLM is set
HSET = 1 indicates handset DAC/ADC is supported – not supported on TLV320AIC27
CID1 = 1 indicates that caller ID decode for line1 is supported – not supported on TLV320AIC27
CID2 = 1 indicates that caller ID decode for line2 is supported – not supported on TLV320AIC27
ID1, ID0 is a two-bit field which indicates the codec configuration: primary is 00; secondary is 01, 10, or 11
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register 3Eh – extended modem status control
The extended modem status and control register functions similarly to the original AC’97 power-down
control/status register, located at index 26h. The (A)MC ’97 Codec must restrict modem and handset
power-down control/status to this register since all of the functions are provided here. Therefore, the (A)MC’97
codec (and AC’97 digital controller, of course) must ignore bits MDM and PR7 in register 26h and use what is
included here. When the GPIO section is powered down, all outputs must be 3-state and input slot 12 should
be marked invalid when the ac link is active. When slot 12 is invalid, register 54h (GPIO pin status register) will
report 0s. In addition the codec should force SDATA_IN slot 12 to all 0s. Bits 7 to 0 are read only, 1 indicates
modem AFE subsystem readiness
D
D
D
D
D
D
D
D
GPIO = 1 indicates GPIO ready
MREF = 1 indicates modem VREFs up to nominal level
ADC1 = 1 indicates modem line1 ADC ready
DAC1 = 1 indicates modem line1 DAC ready
ADC2 = 1 indicates modem line2 ADC ready – supported on TLV320AIC27 when in DLM is set
DAC2 = 1 indicates modem line2 DAC ready –supported on TLV320AIC27 when DLM is set
HADC = 1 indicates handset ADC ready – not supported on TLV320AIC27
HDAC = 1 indicates handset DAC ready – not supported on TLV320AIC27
Bits 15 to 8 are read/write and control modem AFE subsystem power down. TLV320AIC27 power-up/down
functions are entirely controlled from register 26h. However, the following registers are aliased onto the
appropriate control bits in registers 26h.
D
D
D
D
D
D
D
D
PRA = 1 indicates GPIO power-down
PRB = 1 indicates modem VREF off – no separate modem VREF on TLV320AIC27, aliases from PR3
PRC = 1 indicates modem line1 ADC off – aliases from PR0
PRD = 1 indicates modem line1 DAC off – aliases from PR1
PRE = 1 indicates modem line2 ADC off – not supported on TLV320AIC27
PRF = 1 indicates modem line2 DAC off – not supported on TLV320AIC27
PRG = 1 indicates handset ADC off – not supported on TLV320AIC27
PRH = 1 indicates handset DAC off – not supported on TLV320AIC27
Bits 7 to 0 are read only, 1 indicates modem AFE subsystem readiness. Bits 15 to 8 are read/write and control
modem AFE subsystem power down. Writing ENABLES (0) to the above aliased PR bits is allowed and will write
enable to appropriate PRN bit. However, writing DISABLES (1) is not allowed.
register 40h – line1 ADC DAC sample rate
This read/write register 40h controls the modem DAC and ADC sample rate. This register is only functional if
modem mode1 = 1 is selected from pins 30 and 40. The ADC will only use this sample rate if in addition, the
input to the Record Mux is selected, as Right ADC is PHONE in register 1Ah. Note only the recommended
sample rates are supported. If alternative sample rates are selected the rate will default to the nearest sample
rate supported, and that value will be read back
register 46h to 48h – line1 and line2 ADC level
These registers are not supported in TLV320AIC27, register 04h being used to control TX modem level.
register 56h – miscellaneous modem AFE status/control
This read/write register defines the loop back modes available for the modem line and handset ADCs/DACs
described in the Intel specification. Line1 ADC loopback mode 001 L1B0 is supported.
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43
44
Mute
Mute
LNLVL volume
Master volume mono
PCBEEP volume
Phone volume
Mic volume
Line in volume
CD volume
Video volume
Aux volume
04h
06h
0Ah
0Ch
0Eh
10h
12h
14h
16h
X
EAPD
ID1
Mute
Mute
ID1
PRH
SR15
Sample rates written to 42h will alias onto 40h
Reserved
Power/down control
status
Extended audio ID
Extended audio stat/ctrl
Front DAC rate
Rear DAC rate
LFE DAC rate
Audio ADC rate
6Ch Vol C,LFE
6Ch Vol L,R Surr
Extended modem ID
Extended modem
status
Line1 sample rate
ADC/DAC
Line2 sample rate
ADC/DAC
Line1 DAC/ADC level
26h
28h
2Ah
2Ch
2Eh
30h
32h
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
36h
38h
3Ch
3Eh
40h
42h
46h
SR14
PRG
ID0
X
X
SR14
SR14
SR14
SR14
PRL
ID0
SR13
PRF
X
X
X
SR13
SR13
SR13
SR13
PRK
X
PR5
X
X
SR12
PRE
X
LSR4
LFE4
SR12
SR12
SR12
SR12
PRJ
X
PR4
X
X
SR11
PD
X
LSR3
LFE3
SR11
SR11
SR11
SR11
PRI
X
PR3
X
X
X
GL3
SR10
PRC
X
LSR2
LFE2
SR10
SR10
SR10
SR10
X
X
PR2
X
X
X
GL2
SR9
PRB
X
LSR1
LFE1
SR9
SR9
SR9
SR9
Madc
Amap
PR1
X
X
MIX
GL1
SL1
GL1
GL1
GL1
GL1
GL1
X
X
X
X
ML1
ML1
ID9
D9
SR8
PRA
X
LSR0
LFE0
SR8
SR8
SR8
SR8
Ldac
Ldac
PR0
X
X
MS
GL0
SL0
GL0
GL0
GL0
GL0
GL0
X
X
X
X
ML0
ML0
ID8
D8
Not supported – set TX modem levels by writing to rear DAC PGA 04h
SR15
SR15
SR15
SR15
X
PR6
X
X
lD
X
SL2
24h
X
3D
X
X
3D control
ST
X
X
22h
POP
Mute
X
General-purpose
X
Record gain
X
20h
GL2
GL2
GL2
GL2
GL2
X
X
X
X
ML2
ML2
SE0
D10
1Ch
GL3
GL3
GL3
GL3
GL3
X
X
X
X
ML3
ML3
SE1
D11
Record select
GL4
GL4
GL4
GL4
GL4
X
X
X
X
ML4
ML4
SE2
D12
PCM out volume
X
X
X
X
X
X
X
X
X
X
X
SE3
D13
18h
X
X
X
X
X
X
X
X
X
X
X
SE4
D14
1Ah
Mute
Mute
Mute
Mute
Mute
Mute
Mute
Mute
Mute
Master volume
X
Reset
D15
02h
NAME
00h
REG
SR7
HDAC
X
Mute
Mute
SR7
SR7
SR7
SR7
Sdac
Sdac
X
X
X
LPBK
X
X
X
X
X
X
X
X
X
X
X
X
X
ID7
D7
SR6
HADC
X
X
X
SR6
SR6
SR6
SR6
Cdac
Cdac
X
X
X
X
X
X
X
X
X
X
X
20dB
X
X
X
X
X
ID6
D6
SR5
DAC2
X
X
X
SR5
SR5
SR5
SR5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
ID5
D5
Table 23. Serial Interface Register Map Description
SR4
ADC2
CID2
RSR4
CNT4
SR4
SR4
SR4
SR4
X
X
X
X
X
X
X
X
GR4
GR4
GR4
GR4
GR4
GN4
GN4
PV3
MM4
MR4
MR4
ID4
D4
SR3
DAC1
CID1
RSR3
CNT3
SR3
SR3
SR3
SR3
VRM
VRM
REF
X
DP3
X
GR3
X
GR3
GR3
GR3
GR3
GR3
GN3
GN3
PV2
MM3
MR3
MR3
ID3
D3
SR2
ADC1
HSET
RSR2
CNT2
SR2
SR2
SR2
SR2
X
X
ANL
X
DP2
X
GR2
SR2
GR2
GR2
GR2
GR2
GR2
GN2
GN2
PV2
MM2
MR2
MR2
ID2
D2
SR1
MREF
LIN2
RSR1
CNT1
SR1
SR1
SR1
SR1
DRA
DRA
DAC
X
DP1
X
GR1
SR1
GR1
GR1
GR1
GR1
GR1
GN1
GN1
PV0
MM1
MR1
MR1
ID1
D1
SR0
GPIO
LIN1
RSR0
CNT0
SR0
SR0
SR0
SR0
VRA
VRA
ADC
X
DP0
X
GR0
SR0
GR0
GR0
GR0
GR0
GR0
GN0
GN0
X
MM0
MR0
MR0
ID0
D0
NA
NA
BB80h
0100h
x00xh
8080h
8080h
BB80h
BB80h
BB80h
BB80h
0080h
0281h
000Fh
0000h
0000h
8000h
8000h
0000h
8808h
8808h
8808h
8808h
8808h
8008h
8008h
x000h
8000h
8000h
8000h
6150h
DEFAULT
Template Release Date: 7–11–94
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
Table 23. Serial Interface Register Map Description (Continued)
REG
NAME
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D1
D2
D0
DEFAULT
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
48h
Line2 DAC/ADC
level
Not supported – set TX modem levels by writing to rear DAC PGA 04h
NA
4Ch
GPIO pin config
Not supported
NA
4Eh
GGPIO pin type
NA
50h
GGPIO pin sticky
NA
52h
GGPIO wake-up
NA
54h
GGPIO pin status
56h
Misc modem stat/ctrl
CID2
CID1
CIDR
MLNK
x
HSB2
HSB1
HSB0
x
L2B2
L2B1
L2B0
x
L1B2
L1B1
L1B0
0000h
5Ah
Vendor reserved
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
70h
Rear PCM out
volume
Not supported
72h
Front mixer volume
Mute
74h
Rear mixer volume
Not supported
NA
X
NA
X
GL4
GL3
GL2
GL1
GL0
X
X
X
GR4
GR3
GR2
GR1
GR0
8808h
NA
7Ah
Vendor reserved
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
7Ch
Vendor ID1
F7
F6
F5
F4
F3
F2
F1
F0
S7
S6
S5
S4
S3
S2
S1
S0
574Dh
7Eh
Vendor ID2
T7
T6
T5
T4
T3
T2
T1
T0
Rev7
Rev6
Rev5
Rev4
Rev3
Rev2
Rev1
Rev0
4C03h
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
45
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
detailed timing diagrams, AVDD = 5 V, DVDD = 3.3 V, GND = 0 V, TA = 0°C to 70°C (unless otherwise
stated)
All measurements are taken at 10% to 90% VDD, unless otherwise stated. All the following timing information
is assured, not tested.
SYNC
SLOT 1
SLOT 2
WRITE
TO 0X20
DATA PR4
BIT_CLK
SDATA_OUT
DON’T
CARE
t(S2_PDOWN)
SDATA_IN
MIN
PARAMETER
t(S2_PDOWN)
TYP
End of slot 2 to BITCLK SDATIN low
MAX
1
UNIT
µs
Figure 15. AC-Link Power-Down Timing
t(RST_LOW)
t(RST2CLK)
RESETB
BIT_CLK
PARAMETER
t(RST_LOW)
RESETB active-low pulse width
t(RST2_CLK)
RESETB inactive to BIT_CLK startup delay
MIN
Figure 16. Cold Reset Timing
46
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TYP
MAX
UNIT
1
µs
162.8
ns
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
detailed timing diagrams, AVDD = 5 V, DVDD = 3.3 V, GND = 0 V, TA = 0°C to 70°C (unless otherwise
stated) (continued)
t(SYNC_HIGH)
t(SYNC2CLK)
SYNC
BIT_CLK
PARAMETER
t(SYNC_HIGH)
SYNC active high pulsewidth
t(SYNC2_CLK)
SYNC inactive to BIT_CLK startup delay
MIN
TYP
MAX
UNIT
µs
1.3
162.4
ns
Figure 17. Warm Reset Timing
t(CLK_HIGH)
t(CLK_LOW)
BIT_CLK
t(CLK_PERIOD)
tCLK_HIGH
(SYNC_HIGH)
t(SYNC_LOW)
SYNC
tSYNC_PERIOD
PARAMETER
MIN
BIT_CLK frequency
t(CLK_PERIOD)
TYP
MAX
12.288
BIT_CLK period
MHz
81.4
BIT_CLK output jitter
ns
750
ps
ms
t(CLK_HIGH)
BIT_CLK high pulse width (see Note 2)
32.56
40.7
48.84
t(CLK_LOW)
BIT_CLK low pulse width (see Note 2)
32.56
40.7
48.84
SYNC frequency
t(SYNC_PERIOD)
SYNC period
t(SYNC_HIGH)
SYNC high pulse width
48
t(SYNC_LOW)
SYNC low pulse width
NOTE 2: Worst-case duty cycle restricted to 40/60.
UNIT
ns
kHz
20.8
µs
1.3
µs
19.5
µs
Figure 18. Clock Specifications (50-pF external load)
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
47
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
detailed timing diagrams, AVDD = 5 V, DVDD = 3.3 V, GND = 0 V, TA = 0°C to 70°C (unless otherwise
stated) (continued)
tsu
BIT_CLK
th
SYNC
SDATA_OUT
PARAMETER
tsu
th
MIN
Setup to falling edge of BIT_CLK
Hold from falling edge of BIT_CLK
TYP
MAX
UNIT
15
ns
5
ns
NOTE: Setup and hold time parameters for SDATA_IN are with respect to AC’97 controller.
Figure 19. Data Setup and Hold (50 pF external load)
tr(CLK)
tf(CLK)
BIT_CLK
tr(SYNC)
tf(SYNC)
SYNC
tr(DIN)
tf(DIN)
SDATA_IN
tr(DOUT)
tf(DOUT)
SDATA_OUT
PARAMETER
MIN
TYP
MAX
UNIT
tr(CLK)
tf(CLK)
BIT_CLK rise time
2
6
ns
BIT_CLK fall time
2
6
ns
tr(SYNC)
tf(SYNC)
SYNC rise time
2
6
ns
SYNC fall time
2
6
ns
tr(DIN)
tf(DIN)
SDATA_IN rise time
2
6
ns
SDATA_IN fall time
2
6
ns
tr(DOUT)
tf(DOUT)
SDATA_OUT rise time
2
6
ns
SDATA_OUT fall time
2
6
ns
Figure 20. Signal Rise and Fall Times (50-pF external load)
48
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
recommended external components
DVDD
AVDD
TLV320AIC27
1
9
C1
4
C2
7
DVDD1
AVDD1
DVDD2
AVDD2
DVSS1
AVSS1
DVSS2
AVSS2
25
38
C3
C4
26
42
DGND
MIXER
INPUTS
C5
12
C6
13
C7
14
C8
15
C9
16
C10
17
C11
18
C12
19
C13
20
C14
21
C15
22
C16
23
C17
24
30
40
VREF
PCBEEP
VREFOUT
PHONE
AUXL
AFILT1
AUXR
CAP1
VIDEOL
CAP2
AVDD
46
45
AC–LINK
8
10
11
C18
C19
C20 +
31
32
C23
C21 C22 +
C25
+
+
AGND
C26
CDL
CDGND
CDR
CX3D1
MIC1
CX3D2
AGND
33
C27
34
C28
MIC2
AGND
LINEINL
LINEOUTL
LINEINR
LINEOUTR
M0
MONOOUT
M1
CID1
LNLVLOUTR
CID2
GPIO1
GPIO2
6
29
C24
AVSS
5
28
VIDEOR
LNLVLOUTL
OERATIONAL
MODE
CONTROL
AGND
27
SDATAOUT
GPIO3
BITCLK
EAPD4
35
+
C29
36
+
C30
37
+
C31
39
+
C32
41
+
C33
43
STEREO OUTPUT
MONO OUTPUT
LINE LEVEL STEREO
(MODEM OUT)
44
To I2S DACs/DAA CONTROL
48
47
SDATAIN
SYNC
RESETB
XTLIN
XTLOUT
2
NOTES: A. Pins 27, 29 and 31 are internally
connected. It is recommended that
capacitors only be connected to one
of these pins.
3
B. C1 to C28 should be as close to
AIC27 as possible.
XT
C34
C35
DGND
C. AGND and DGND should be
connected as close to AIC27 as
possible.
Figure 21. External Components Diagram
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
49
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
recommended external components values
Table 24. External Component Values
COMPONENT
REFERENCE
SUGGESTED
VALUE
C1 to C4
10 nF
Decoupling for DVDD and AVDD
C5 to C17
470 nF
AC coupling capacitors for setting dc level of analog inputs to VCAP1. Value chosen to give corner frequency
below 20 Hz for a minimum of 10-KΩ input impedance.
C18
1 µF
C19
0.1 µF
C20
10 µF
C21
0.1 µF
C22
10 µF
C23
0.1 µF
C24
10 µF
C25
0.1 µF
C26
10 µF
C27
100 nF
3D low-pass filter. This value sets nominal 100 Hz.
C28
47 nF
3D high-pass filter. This value sets nominal 1 kHz.
C29 to C33
10 µF
Output ac-coupling caps to remove VREF dc level from outputs
C34 and C35
22 pF
Optional capacitors for better crystal frequency stability
XT
24.576 MHz
AC’97 master clock frequency. A bias resistor is not required, but if connected will not affect operation if value
is large (above 1 MΩ).
DESCRIPTION
Reference decoupling capacitors for ADC, DAC, Mixer, and CAP2 references. Ceramic type or similar.
recommendations for 3.3-V operation
The device performance with AVDD = 3.3 V is shown in the electrical characteristics section.
In 3.3-V analog operation, midrail reference scales to 1.5 V. All ADC and DAC references are 3/5 of their nominal
5-V value. Input and output signals that are 1 Vrms in 5-V applications scale to 660 mVrms in 3.3-V applications.
If 1-Vrms output is required, the mixer gain-adjust PGAs need to be increased by a factor of 3 in 1.5-dB steps.
50
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV320AIC27
STEREO AUDIO CODEC
SLAS253 – MARCH 2000
MECHANICAL DATA
PFB (S-PQFP-G48)
PLASTIC QUAD FLATPACK
0,27
0,17
0,50
36
0,08 M
25
37
24
48
13
0,13 NOM
1
12
5,50 TYP
7,20
SQ
6,80
9,20
SQ
8,80
Gage Plane
0,25
0,05 MIN
0°– 7°
1,05
0,95
Seating Plane
0,75
0,45
0,08
1,20 MAX
4073176 / B 10/96
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Falls within JEDEC MS-026
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
51
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accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
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Of course, customers are responsible for their applications using TI components.
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Copyright  2000, Texas Instruments Incorporated