IDT STAC9752

DATASHEET
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE
DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Description
IDT's STAC9752/9753 are general purpose 20-bit, full
duplex, audio CODECs conforming to the analog
component specification of AC'97 (Audio CODEC 97
Component Specification Rev. 2.3). The STAC9752/9753
incorporate IDT's proprietary Σ∆ technology to achieve a
DAC SNR in excess of 90dB. The DACs, ADCs and mixer
are integrated with analog I/Os, which include four analog
line-level stereo inputs, two analog line-level mono inputs,
two stereo outputs, and one mono output channel. The
STAC9752/9753 include digital output capability for support
of modern PC systems with an output that supports the
SPDIF format. The STAC9752/9753 are standard
2-channel stereo CODECs. With IDT’s headphone
capability, headphones can be driven without an external
amplifier. The STAC9752/9753 may be used as a
secondary or tertiary CODECs, with STAC9700/21/44/56/
08/84/50/66 as the primary, in a multiple CODEC
configuration conforming to the AC'97 Rev. 2.3
specification. This configuration can provide the true
six-channel, AC-3 playback required for DVD applications.
The STAC9752/9753 communicate via the five AC-Link
lines to any digital component of AC'97, providing flexibility
in the audio system design. Packaged in an AC'97
compliant 48-pin TQFP, the STAC9752/9753 can be placed
on the motherboard, daughter boards, PCI, AMR, CNR,
MDC or ACR cards.
Features
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High performance Σ∆ technology
AC’97 Rev 2.3 compliant
20-bit full duplex stereo ADCs, DACs
STAC9752/9753
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5-wire AC-Link protocol compliance
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+3.3 V (STAC9753) and +5 V (STAC9752) analog
power supply options
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Pin compatible with the STAC9700, STAC9721,
STAC9756
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100% pin compatible with STAC9750 and
STAC9766
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IDT Surround (SS3D) Stereo Enhancement
20-bit SPDIF Output
Internal Jack Sensing on Headphone and Line_Out
Internal Microphone Input Sensing
Digital PC Beep Option
Extended AC’97 2.3 Paging Registers
Adjustable VREF amplifier
Digital-ready status
General purpose I/Os
Crystal Elimination Circuit
Headphone drive capability (50 mW)
0dB, 10dB, 20dB, and 30dB microphone boost
capability
Energy saving dynamic power modes
Multi-CODEC option (Intel AC'97 rev 2.3)
Six analog line-level inputs
90dB SNR Line to Line
SNR > 89dB through Mixer and DAC
Independent sample rates for ADCs & DACs
IDT™
1
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
V 3.3 101006
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
TABLE OF CONTENTS
1. PRODUCT BRIEF ...................................................................................................................... 7
1.1. Description ........................................................................................................................................ 7
1.2. STAC9752/9753 Block Diagram ........................................................................................................ 8
1.3. Key Specifications ............................................................................................................................. 8
1.4. Related Materials .............................................................................................................................. 9
1.5. Additional Support ............................................................................................................................. 9
2. CHARACTERISTICS AND SPECIFICATIONS .......................................................................10
2.1. Electrical Specifications ................................................................................................................... 10
2.1.1. Absolute Maximum Ratings ............................................................................................... 10
2.1.2. Recommended Operation Conditions .............................................................................. 10
2.1.3. Power Consumption ......................................................................................................... 11
2.1.4. AC-Link Static Digital Specifications ................................................................................. 12
2.1.5. STAC9752 5 V Analog Performance Characteristics ....................................................... 12
2.1.6. STAC9753 3.3V Analog Performance Characteristics .....................................................14
2.2. AC Timing Characteristics ............................................................................................................... 16
2.2.1. Cold Reset ......................................................................................................................... 16
2.2.2. Warm Reset ....................................................................................................................... 16
2.2.3. Clocks ................................................................................................................................ 17
2.2.4. STAC9752/9753 Crystal Elimination Circuit and Clock Frequencies ................................17
2.2.5. Data Setup and Hold ........................................................................................................ 18
2.2.6. Signal Rise and Fall Times ............................................................................................... 18
2.2.7. AC-Link Low Power Mode Timing .................................................................................... 19
2.2.8. ATE Test Mode ................................................................................................................. 19
3. TYPICAL CONNECTION DIAGRAM .......................................................................................20
3.1. Slit Independent Power Supply Operation ...................................................................................... 21
4. CONTROLLER, CODEC AND AC-LINK .................................................................................23
4.1. AC-Link Physical Interface .............................................................................................................. 23
4.2. Controller to Single CODEC ............................................................................................................ 23
4.3. Controller to Multiple CODECs ........................................................................................................ 25
4.3.1. Primary CODEC Addressing ............................................................................................. 25
4.3.2. Secondary CODEC Addressing ........................................................................................ 25
4.3.3. CODEC ID Strapping ......................................................................................................... 26
4.4. Clocking for Multiple CODEC Implementations ............................................................................... 26
4.5. STAC9752/9753 as a Primary CODEC ........................................................................................... 26
4.5.1. STAC9752/9753 as a Secondary CODEC ........................................................................ 26
4.6. AC-Link Power Management ........................................................................................................... 27
4.6.1. Powering down the AC-Link .............................................................................................. 27
4.6.2. Waking up the AC-Link ...................................................................................................... 27
4.6.3. CODEC Reset ................................................................................................................... 28
5. AC-LINK DIGITAL INTERFACE ..............................................................................................29
5.1. Overview ......................................................................................................................................... 29
5.2. AC-Link Serial Interface Protocol .................................................................................................... 30
5.2.1. AC-Link Variable Sample Rate Operation ......................................................................... 30
5.2.2. Variable Sample Rate Signaling Protocol .......................................................................... 30
5.2.3. Primary and Secondary CODEC Register Addressing ...................................................... 32
5.3. AC-Link Output Frame (SDATA_OUT) ............................................................................................ 32
5.3.1. Slot 0: TAG / CODEC ID ................................................................................................... 34
5.3.2. Slot 1: Command Address Port ......................................................................................... 34
5.3.3. Slot 2: Command Data Port ............................................................................................... 35
5.3.4. Slot 3: PCM Playback Left Channel .................................................................................. 35
5.3.5. Slot 4: PCM Playback Right Channel ................................................................................ 35
5.3.6. Slot 5: Modem Line 1 Output Channel .............................................................................. 35
5.3.7. Slot 6 - 11: DAC ................................................................................................................. 35
IDT™
2
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
5.3.8. Slot 12: Audio GPIO Control Channel ............................................................................... 36
5.4. AC-Link Input Frame (SDATA_IN) ................................................................................................. 36
5.4.1. Slot 0: TAG ........................................................................................................................37
5.4.2. Slot 1: Status Address Port / SLOTREQ signalling bits .....................................................37
5.4.3. Slot 2: Status Data Port ..................................................................................................... 38
5.4.4. Slot 3: PCM Record Left Channel ..................................................................................... 38
5.4.5. Slot 4: PCM Record Right Channel ................................................................................... 38
5.4.6. Slot 5: Modem Line 1 ADC ................................................................................................ 38
5.4.7. Slot 6 - 9: ADC ................................................................................................................... 38
5.4.8. Slots 7 & 8: Vendor Reserved ........................................................................................... 39
5.4.9. Slot 10 & 11: ADC ............................................................................................................. 39
5.4.10. Slot 12: Reserved ............................................................................................................ 39
5.5. AC-Link Interoperability Requirements and Recommendations ...................................................... 40
5.5.1. “Atomic slot” Treatment of Slot 1 Address and Slot 2 Data ...............................................40
5.6. Slot Assignments for Audio ............................................................................................................. 41
6. STAC9752/9753 MIXER ..........................................................................................................43
7. MIXER FUNCTIONAL DIAGRAMS ........................................................................................44
7.1. Analog Mixer Input ......................................................................................................................... 45
7.2. Mixer Analog Output ....................................................................................................................... 45
7.3. SPDIF Digital Mux ...........................................................................................................................45
7.4. PC Beep Implementation ................................................................................................................ 46
7.4.1. Analog PC Beep ................................................................................................................ 46
7.4.2. Digital PC Beep ................................................................................................................. 46
8. PROGRAMMING REGISTERS ...............................................................................................47
8.1. Register Descriptions ...................................................................................................................... 48
8.1.1. Reset (00h) ....................................................................................................................... 48
8.1.2. Master Volume Registers (02h) ........................................................................................ 48
8.1.3. Headphone Volume Registers (04h) ................................................................................. 49
8.1.4. Master Volume MONO (06h) ............................................................................................ 50
8.1.5. PC BEEP Volume (0Ah) ................................................................................................... 51
8.1.6. Phone Volume (Index 0Ch) .............................................................................................. 51
8.1.7. Mic Volume (Index 0Eh) .................................................................................................... 52
8.1.8. LineIn Volume (Index 10h) ............................................................................................... 52
8.1.9. CD Volume (Index 12h) .................................................................................................... 53
8.1.10. Video Volume (Index 14h) ............................................................................................. 53
8.1.11. Aux Volume (Index 16h) ................................................................................................. 54
8.1.12. PCMOut Volume (Index 18h) ......................................................................................... 54
8.1.13. Record Select (1Ah) ....................................................................................................... 55
8.1.14. Record Gain (1Ch) ......................................................................................................... 55
8.1.15. General Purpose (20h) ................................................................................................... 56
8.1.16. 3D Control (22h) ............................................................................................................. 56
8.1.17. Audio Interrupt and Paging (24h) .................................................................................... 57
8.1.18. Powerdown Ctrl/Stat (26h) .............................................................................................. 58
8.1.19. Extended Audio ID (28h) ................................................................................................ 59
8.1.20. Extended Audio Control/Status (2Ah) ............................................................................. 61
8.1.21. PCM DAC Rate Registers (2Ch and 32h) ...................................................................... 63
8.1.22. PCM DAC Rate (2Ch) .................................................................................................... 63
8.1.23. PCM LR ADC Rate (32h) ............................................................................................... 63
8.1.24. SPDIF Control (3Ah) ........................................................................................................ 64
8.2. General Purpose Input & Outputs ................................................................................................... 64
8.2.1. EAPD ................................................................................................................................. 64
8.2.2. GPIO Pin Definitions .......................................................................................................... 65
8.2.3. GPIO Pin Implementation .................................................................................................. 65
8.2.4. Extended Modem Status and Control Register (3Eh) ........................................................65
8.2.5. GPIO Pin Configuration Register (4Ch) ............................................................................. 66
IDT™
3
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
8.2.6. GPIO Pin Polarity/Type Register (4Eh) ............................................................................. 66
8.2.7. GPIO Pin Sticky Register (50h) ......................................................................................... 66
8.2.8. GPIO Pin Mask Register (52h) .......................................................................................... 67
8.2.9. GPIO Pin Status Register (54h) ........................................................................................ 67
8.3. Extended CODEC Registers Page Structure Definition .................................................................. 68
8.3.1. Extended Registers Page 00 ............................................................................................. 68
8.3.2. Extended Registers Page 01 ............................................................................................. 68
8.3.3. Extended Registers Page 02, 03 ....................................................................................... 68
8.4. STAC9752/9753 Paging Registers ................................................................................................. 69
8.4.1. CODEC Class/Rev (60h Page 01h ) ............................................................................... 69
8.4.2. PCI SVID (62h Page 01h ) ............................................................................................... 70
8.4.3. PCI SSID (64h Page 01h ) ............................................................................................... 70
8.4.4. Function Select (66h Page 01h) ...................................................................................... 71
8.4.5. Function Information (68h Page 01h ) .............................................................................. 72
8.4.6. Digital Audio Control (6Ah, Page 00h) ............................................................................... 73
8.4.7. Sense Details (6Ah Page 01h ) ........................................................................................ 74
8.4.8. Revision Code (6Ch) ........................................................................................................ 76
8.4.9. Analog Special (6Eh) ......................................................................................................... 76
8.4.10. Analog Current Adjust (72h) ............................................................................................ 77
8.4.11. EAPD Access Register (74h) .......................................................................................... 77
8.4.12. High Pass Filter Bypass (78h) ........................................................................................ 78
8.5. Vendor ID1 and ID2 (Index 7Ch and 7Eh) ...................................................................................... 79
8.5.1. Vendor ID1 (7Ch) ............................................................................................................. 79
8.5.2. Vendor ID2 (7Eh) ............................................................................................................... 79
9. LOW POWER MODES ...........................................................................................................80
10. MULTIPLE CODEC SUPPORT ............................................................................................82
10.1. Primary/Secondary CODEC Selection .......................................................................................... 82
10.1.1. Primary CODEC Operation ............................................................................................ 82
10.1.2. Secondary CODEC Operation ........................................................................................ 82
10.2. Secondary CODEC Register Access Definitions .......................................................................... 83
11. TESTABILITY ........................................................................................................................84
11.0.1. ATE Test Mode ................................................................................................................ 84
12. PIN DESCRIPTION ................................................................................................................85
12.1. Digital I/O ...................................................................................................................................... 86
12.2. Analog I/O .................................................................................................................................... 87
12.3. Filter/References .......................................................................................................................... 88
12.4. Power and Ground Signals .......................................................................................................... 88
13. ORDERING INFORMATION ..................................................................................................89
14. PACKAGE DRAWING ...........................................................................................................89
15. 48-PIN LQFP SOLDER REFLOW PROFILE .........................................................................90
15.1. Standard Reflow Profile Data ........................................................................................................ 90
15.2. Pb Free Process - Package Classification Reflow Temperatures ................................................. 91
16. APPENDIX A: PROGRAMMING REGISTERS .....................................................................92
17. REVISION HISTORY .............................................................................................................94
IDT™
4
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
LIST OF FIGURES
Figure 1. Block Diagram ................................................................................................................................. 8
Figure 2. Cold Reset Timing ......................................................................................................................... 16
Figure 3. Warm Reset Timing ....................................................................................................................... 16
Figure 4. Clocks Timing ............................................................................................................................... 17
Figure 5. Data Setup and Hold Timing ......................................................................................................... 18
Figure 6. Signal Rise and Fall Times Timing ................................................................................................ 18
Figure 7. AC-Link Low Power Mode Timing
.............................................................................................. 19
Figure 8. ATE Test Mode Timing ............................................................................................................... 19
Figure 9. Typical Connection Diagram .......................................................................................................... 20
Figure 10. Split Independent Power Supply Operation ................................................................................. 22
Figure 11. AC-Link to its Companion Controller ........................................................................................... 23
Figure 12. CODEC Clock Source Detection .................................................................................................. 24
Figure 13. STAC9752/9753 Powerdown Timing .......................................................................................... 27
Figure 14. Bi-directional AC-Link Frame with Slot assignments ................................................................... 29
Figure 15. AC-Link Audio Output Frame ...................................................................................................... 33
Figure 16. Start of an Audio Output Frame ................................................................................................... 33
Figure 17. STAC9752/9753 Audio Input Frame ........................................................................................... 36
Figure 18. Start of an Audio Input Frame ...................................................................................................... 36
Figure 19. Bi-directional AC-Link Frame with Slot assignments ................................................................... 41
Figure 20. STAC9752 2-Channel Mixer Functional Diagram ........................................................................ 44
Figure 21. STAC9753 2-Channel Mixer Functional Diagram .......................................................................44
Figure 22. Example of STAC9752/9753 Powerdown/Powerup flow ...........................................................80
Figure 23. Powerdown/Powerup flow with analog still alive ......................................................................... 81
Figure 24. Pin Description Drawing ............................................................................................................... 85
Figure 25. Reflow Profile ..............................................................................................................................90
IDT™
5
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
LIST OF TABLES
Table 1. Clock Mode Configuration ............................................................................................................... 17
Table 2. Common Clocks and Sources ......................................................................................................... 18
Table 3. Recommended CODEC ID strapping ............................................................................................. 26
Table 4. AC-Link output slots (transmitted from the Controller) ..................................................................... 29
Table 5. The AC-Link input slots (transmitted from the CODEC) .................................................................. 30
Table 6. VRA Behavior .................................................................................................................................. 31
Table 7. Output Slot 0 Bit Definitions ............................................................................................................ 34
Table 8. Command Address Port Bit Assignments ........................................................................................ 35
Table 9. Status Address Port Bit Assignments .............................................................................................. 37
Table 10. Status Data Port Bit Assignments .................................................................................................. 38
Table 11. Primary CODEC Addressing: Slot 0 Tag Bits ................................................................................ 40
Table 12. Secondary CODEC Addressing: Slot 0 Tag Bits ........................................................................... 40
Table 13. AC-Link Slot Definitions ................................................................................................................. 41
Table 14. AC-Link Input Slots Dedicated To Audio ....................................................................................... 41
Table 15. Audio Interrupt Slot Definitions ...................................................................................................... 42
Table 16. Digital PC Beep Examples ............................................................................................................. 46
Table 17. Programming Registers ................................................................................................................. 47
Table 18. Extended Audio ID Register Functions .......................................................................................... 60
Table 19. AMAP compliant ............................................................................................................................ 63
Table 20. Hardware Supported Sample Rates .............................................................................................. 63
Table 21. Supported Jack and Microphone Sense Functions .......................................................................71
Table 22. Reg 68h Default Values ................................................................................................................. 73
Table 23. Gain or Attenuation Examples ....................................................................................................... 73
Table 24. Register 68h/Page 01h Bit Overview ............................................................................................. 73
Table 25. Sensed Bits (Outputs) ................................................................................................................... 75
Table 26. Sensed Bits (Inputs) ...................................................................................................................... 75
Table 27. Low Power Modes ......................................................................................................................... 80
Table 28. CODEC ID Selection .....................................................................................................................82
Table 29. Secondary CODEC Register Access Slot 0 Bit Definitions ...........................................................83
Table 30. Test Mode Activation .....................................................................................................................84
Table 31. ATE Test Mode Operation ............................................................................................................. 84
Table 32. Digital Connection Signals ............................................................................................................. 86
Table 33. Analog Connection Signals ........................................................................................................... 87
Table 34. Filtering and Voltage References .................................................................................................. 88
Table 35. Power and Ground Signals ............................................................................................................ 88
IDT™
6
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
1. PRODUCT BRIEF
1.1.
Description
IDT's STAC9752/9753 are general purpose 20-bit, full duplex, audio CODECs conforming to the
analog component specification of AC'97 (Audio CODEC 97 Component Specification Rev. 2.3).
The STAC9752/9753 incorporate IDT's proprietary Σ∆ technology to achieve a DAC SNR in excess
of 90dB. The DACs, ADCs and mixer are integrated with analog I/Os, which include four analog
line-level stereo inputs, two analog line-level mono inputs, two stereo outputs, and one mono output
channel. The STAC9752/9753 include digital output capability for support of modern PC systems
with an output that supports the SPDIF format. The STAC9752/9753 are standard 2-channel stereo
CODECs. With IDT’s headphone capability, headphones can be driven without an external amplifier.
The STAC9752/9753 may be used as a secondary or tertiary CODECs, with STAC9700/21/44/56/
08/84/50/66 as the primary, in a multiple CODEC configuration conforming to the AC'97 Rev. 2.3
specification. This configuration can provide the true six-channel, AC-3 playback required for DVD
applications. The STAC9752/9753 communicate via the five AC-Link lines to any digital component
of AC'97, providing flexibility in the audio system design. Packaged in an AC'97 compliant 48-pin
TQFP, the STAC9752/9753 can be placed on the motherboard, daughter boards, PCI, AMR, CNR,
MDC or ACR cards.
The STAC9752/9753 block diagram is illustrated in Figure 1. The STAC9752/9753 provides variable
sample rate Digital-to-Analog (DA) and Analog-to-Digital (AD) conversion, mixing, and analog processing. Supported audio sample rates include 48 KHz, 44.1 KHz, 32 KHz, 22.05 KHz, 16 KHz,
11.025 KHz, and 8 KHz; additional rates are supported in the STAC9752/9753 soft audio drivers. All
ADCs and DACs operate at 20-bit resolution.
Two 20-bit DACs convert the digital stereo PCM_OUT content to audio. The MIXER block combines
the PCM_OUT with any analog sources, to drive the LINE_OUT and HP_OUT outputs. The
MONO_OUT delivers either microphone only, or a mono mix of sources from the MIXER. The stereo
variable-sample-rate 20-bit ADCs provide record capability for any mix of mono or stereo sources,
and deliver a digital stereo PCM-in signal back to the AC-Link. The microphone input and mono mix
input can be recorded simultaneously, thus allowing for an all digital output in support of the digital
ready initiative. For a digital ready record path, the microphone is connected to the left channel ADC
while the mono output of the stereo mixer is connected to right channel ADC.
The STAC9752/9753 include jack sensing on the Headphone and Line_Out. The STAC9752/9753
jack sense can detect the presence of devices on the Headphone and Line Outputs and on both
Microphone inputs. With proprietary IDT current and impedance-sensing techniques, the impedance
load on the Headphone and Line Outputs can also be detected. The GPIOs on the STAC9752/9753
remain available for advanced configurations.
The STAC9752/9753 implementation of jack sense uses the Extended Paging Registers defined by
the AC'97 2.3 Specification. This allows for additional registry space to hold the identification information about the CODEC, the jack sensing details and results, and the external surroundings of the
CODEC. The information within the Extended Paging Registers will allow for the automatic configuration of the audio subsystem without end-user intervention. For example, the BIOS can populate
the Extended Paging Registers with valuable information for both the audio driver and the operating
system such as gain and attenuation stages, input population and input phase. With this input information, the IDT driver will automatically provide to the Volume Control Panel only the volume sliders
that are implemented in the system, thus improving the end-user's experience with the PC.
The information in the Extended Paging Registers will also allow for automatic configuration of
microphone inputs, the ability to switch between SPDIF and analog outputs, the routing of the mas-
IDT™
7
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
ter volume slider to the proper physical output, and SoftEQ configurations. The fully parametric IDT
SoftEQ can be initiated upon jack insertion and sensed impedance levels.
The STAC9752/9753 also offers 2 styles of PC BEEP; Analog and Digital. The digital PC Beep is a
new feature added to the AC’97 Specification Rev 2.3.
The STAC9752/9753 is designed primarily to support stereo (2-speaker) audio. True AC-3 playback
can be achieved for 6-speaker applications by taking advantage of the multi-CODEC option available in the STAC9752/9753 to support multiple CODECs in an AC'97 architecture. Additionally, the
STAC9752/9753 provides for a stereo enhancement feature, IDT Surround 3D (SS3D). SS3D provides the listener with several options for improved speaker separation beyond the normal two- or
four-speaker arrangements.
The STAC9752/9753 can be SoundBlaster ® and Windows Sound System® compatible when used
with IDT’s WDM driver for Windows 98/2K/ME/XP or with Intel/Microsoft driver included with Windows 2K/ME/XP. SoundBlaster is a registered trademark of Creative Labs. Windows is a registered
trademark of Microsoft Corporation.
1.2.
STAC9752/9753 Block Diagram
Figure 1. Block Diagram
4 stereo
sources
Power
Management
2 mono
sources
Stereo
Mono
PCM out DACs
AC-link
SYNC
BIT_CLK
SDATA_OUT
SDATA_IN
RESET#
Multi-Codec
DAC
Digital
Interface
DAC
Registers
64x16 bits
ADC
CID0
CID1
HP_OUT
MIXER
Analog mixing
and Gain Control
LINE_OUT
MONO_OUT
ADC
PCM in ADCs
GPIO1
EAPD
Mic Boost
0,10,20
or 30 dB
GPIO0
Variable Sample Rate
20-Bit DACs and
20-Bit ADCs
1.3.
IDT™
M MIC1
U
X
MIC2
SPDIF
Key Specifications
•
Analog LINE_OUT SNR: 90 dB
•
STAC9752 DAC SNR: 89 dB
•
STAC9753 DAC SNR: 84dB
•
STAC9752 ADC SNR: 90 dB
•
STAC9753 ADC SNR: 88 dB
•
Crosstalk between Input Channels: -70 dB
•
Spurious Tone Rejection: 100 dB
8
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
1.4.
1.5.
Related Materials
•
Product Brief
•
Reference Designs for MB, AMR, CNR, and ACR applications
•
Audio Precision Performance Plots
Additional Support
Additional product and company information can be obtained by going to the
IDT web site.
IDT™
9
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
2. CHARACTERISTICS AND SPECIFICATIONS
2.1.
Electrical Specifications
2.1.1.
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the STAC9752/9753. These ratings, which are standard
values for IDT commercially rated parts, are stress ratings only. Functional operation of the device at these or any other
conditions above those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum
rating conditions for extended periods can affect product reliability. Electrical parameters are guaranteed only over the
recommended operating temperature range.
Item
Pin
Maximum Rating
Analog maximum supply voltage
AVdd
6 Volts
Digital maximum supply voltage
DVdd
5.5 Volts
VREFOUT output current
5 mA
Voltage on any pin relative to ground
Vss - 0.3 V to Vdd + 0.3 V
Operating temperature
0o C to +70o C
Storage temperature
-55 o C to +125 o C
Soldering temperature
260 o C for 10 seconds *
Soldering temperature information for all available packages
begins on page 90.
2.1.2.
Recommended Operation Conditions
Parameter
Power Supply Voltage
Min.
Typ.
Max.
Units
Digital - 3.3 V
3.135
3.3
3.465
V
Analog - 5 V
4.75
5
5.25
V
Analog - 3.3 V
3.135
3.3
3.465
V
+70
°C
+90
°C
Ambient Operating Temperature
Case Temperature
0
Tcase (48-LQFP)
ESD: The STAC9752/9753 is an ESD (electrostatic discharge) sensitive device. The human body and test
equipment can accumulate and discharge electrostatic charges up to 4000 Volts without detection. Even though
the STAC9752/9753 implements internal ESD protection circuitry, proper ESD precautions should be followed to
avoid damaging the functionality or performance.
IDT™
10
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
2.1.3.
Power Consumption
Parameter
Min
Typ
Max
Digital Supply Current
+ 3.3V Digital
30
Analog Supply Current (at Reset state)
+ 5V Analog
35
+ 3.3V Analog
35
Power Down Status (individually asserted) - All PR measurements taken while unmuted.
+5V Analog Supply Current
50
All paths unmuted
+3.3V Analog Supply Current
44
+3.3V Digital Supply Current
33
+5V Analog Supply Current
42
PR0
+3.3V Analog Supply Current
39
+3.3V Digital Supply Current
22
+5V Analog Supply Current
41
PR1
+3.3V Analog Supply Current
38
+3.3V Digital Supply Current
28
+5V Analog Supply Current
32
PR2
+3.3V Analog Supply Current
29
+3.3V Digital Supply Current
12
+5V Analog Supply Current
23
PR3
+3.3V Analog Supply Current
19
+3.3V Digital Supply Current
12
+5V Analog Supply Current
50
PR4
+3.3V Analog Supply Current
44
+3.3V Digital Supply Current
0.2
+5V Analog Supply Current
50
PR5
+3.3V Analog Supply Current
44
+3.3V Digital Supply Current
12
+5V Analog Supply Current
38
PR6
+3.3V Analog Supply Current
36
+3.3V Digital Supply Current
33
+5V Analog Supply Current
35
PR0 & PR1
+3.3V Analog Supply Current
35
+3.3V Digital Supply Current
12
+5V Analog Supply Current
5
PR0, PR1, PR2, PR6
+3.3V Analog Supply Current
5
+3.3V Digital Supply Current
12
+5V Analog Supply Current
0.6
PR0, PR1, PR2, PR3, PR6
+3.3V Analog Supply Current
0.6
+3.3V Digital Supply Current
12
IDT™
11
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Unit
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
2.1.4.
AC-Link Static Digital Specifications
(T ambient = 25 ºC, DVdd = 3.3V ± 5%, AVss=DVss=0V)
Parameter
Input voltage range
Low level input range
High level input voltage
High level output voltage
Low level output voltage
Input leakage current (AC-Link inputs)
Output leakage current (Hi-Z AC-Link outputs)
BIT_CLK (primary mode) Output leakage current
BIT_CLK (secondary mode) Output leakage current
Output buffer drive current
BIT_CLK/SPDIF Output drive current
Symbol
Vin
Vil
Vih
Voh
Vol
-
Min
-0.30
0.65 x DVdd
0.90 x DVdd
-10
-10
-10
-10
-
Typ
4
18
Max
DVdd + 0.30
0.35 x DVdd
0.1 x DVdd
10
10
100
10
-
Unit
V
V
V
V
V
µA
µA
µA
µA
mA
mA
Note: Due to an internal pulldown resistor, the BIT_CLK pin will exhibit less than 100 µA of leakage current
when the CODEC is configured as primary. This pin meets the +/- 10 µA leakage specification when
configured as secondary.
2.1.5.
STAC9752 5 V Analog Performance Characteristics
(T ambient = 25 ºC, AVdd = 5.0 V ± 5%, DVdd = 3.3 V ± 5%, AVss=DVss=0 V; 1 KHz input sine wave;
Sample Frequency = 48 KHz; 0 dB = 1 Vrms, with a 10 KΩ, 50 pF load, Testbench Characterization
BW: 20 Hz to 20 KHz, 0 dB settings on all gain stages)
Parameter
Full Scale Input Voltage:
All Analog Inputs except Microphone
Microphone Inputs (Note 1)
Full Scale Output:
Line Output
PCM (DAC) to LINE_OUT
MONO_OUT
HEADPHONE_OUT (32 Ω load) per channel (peak)
Dynamic Range: -60dB signal level (Note 2)
CD to LINE_OUT
LINE / AUX / VIDEO to LINE_OUT
PCM (DAC) to LINE_OUT
PCM (DAC) in BYPASS Mode to LINE_OUT
LINE_IN to A/D (1 VRMS Input Referenced)
LINE_IN to HEADPHONE_OUT
Analog Frequency Response (Note 3)
Total Harmonic Distortion + Noise (-3dB): (Note 4)
CD to LINE_OUT
Other to LINE_OUT
PCM (DAC) to LINE_OUT (full scale)
PCM (DAC) in BYPASS Mode to LINE_OUT
LINE_IN to A/D (-3dBV input Level)
IDT™
12
Min
Typ
Max
Unit
-
1.00
0.03
-
Vrms
Vrms
-
1.00
1.00
1.00
50
-
Vrms
Vrms
Vrms
mW
80
80
10
90
90
87
88
90
90
-
30,000
dB
dB
dB
dB
dB
dB
Hz
-
-85
-87
-83
-86
-85
-
dB
dB
dB
dB
dB
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Parameter
HEADPHONE_OUT (32 Ω load)
HEADPHONE_OUT (10 KΩ load)
SNR (idle channel) (Note 5)
DAC to LINE_OUT
DAC in BYPASS Mode
LINE / AUX / VIDEO to LINE_OUT
LINE_IN to A/D with High Pass Filter enabled
A/D & D/A Digital Filter Pass Band (Note 6)
A/D & D/A Digital Filter Transition Band
A/D & D/A Digital Filter Stop Band
A/D & D/A Digital Filter Stop Band Rejection (Note 7)
DAC Out-of-Band Rejection (Note 8)
Group Delay (48 KHz sample rate)
Power Supply Rejection Ratio (1 KHz)
Power Supply Rejection Ratio (20 KHz)
Any Analog Input to LINE_OUT Crosstalk
(10 KHz Signal Frequency)
Any Analog Input to LINE_OUT Crosstalk
(1 KHz Signal Frequency)
Spurious Tone Rejection
Attenuation, Gain Step Size
Input Impedance
Input Capacitance
VREFout
VREF
Interchannel Gain Mismatch ADC
Interchannel Gain Mismatch DAC
Gain Drift
DAC Offset Voltage
Deviation from Linear Phase
LINE_OUT / MONO_OUT Load Resistance
LINE_OUT / MONO_OUT Load Capacitance
HEADPHONE_OUT Load Resistance
HEADPHONE_OUT Load Capacitance
Mute Attenuation
PLL lock time
PLL 24.576 MHz clock jitter
PLL frequency multiplication tolerance
PLL bit clock jitter
Note:
1.
2.
3.
4.
5.
IDT™
Min
-
Typ
-68
Max
-
Unit
dB
-
-81
-
dB
80
20
19,200
28,800
-100
-55
-
90
92
90
92
-70
-40
19,200
28,800
1
-
dB
dB
dB
dB
Hz
Hz
Hz
dB
dB
ms
dB
dB
-
-80
-
dB
-
-100
-
dB
10
90
-
-100
1.5
50
15
0.5 X AVdd
0.45X AVdd
100
10
32
96
100
-
0.5
0.5
20
1
50
100
200
750
12.5
750
dB
dB
KΩ
pF
V
V
dB
dB
ppm/ºC
mV
degrees
KΩ
pF
Ω
pF
dB
µsec
psec
ppm
psec
With +30dB Boost on, 1.00 Vrms with Boost off.
Ratio of Full Scale signal to noise output with -60dB signal, measured “A-weighted” over a 20 Hz to a 20 KHz bandwidth.
± 1dB limits for Line Output & 0 dB gain, at -20dBV
Ratio of Full Scale signal to THD+N output with -3dB signal, measured “A-weighted” over a 20 Hz to a 20 KHz bandwidth.
48 KHz Sample Frequency
Ratio of Full Scale signal to idle channel noise output is measured “A-weighted” over a 20 Hz to a 20 KHz bandwidth.
(AES17-1991 Idle Channel Noise or EIAJ CP-307 Signal-to-noise Ratio).
13
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
6.
7.
8.
Peak-to-Peak Ripple over Passband meets ± 0.25dB limits, 48 KHz Sample Frequency.
Stop Band rejection determines filter requirements. Out-of-Band rejection determines audible noise.
The integrated Out-of-Band noise generated by the DAC process, during normal PCM audio playback, over a bandwidth
28.8 to 100 KHz, with respect to a 1 Vrms DAC output.
2.1.6.
STAC9753 3.3V Analog Performance Characteristics
(T ambient = 25 ºC, AVdd = DVdd = 3.3 V ± 5%, AVss=DVss=0 V; 1 KHz input sine wave; Sample Frequency = 48 KHz; 0 dB = 1 Vrms, with a 10 KΩ, 50 pF load, Testbench Characterization BW: 20 Hz
to 20 KHz, 0 dB settings on all gain stages)
Parameter
Full Scale Input Voltage:
All Analog Inputs except Microphone
Microphone Inputs (Note 1)
Full Scale Output:
Line Output
PCM (DAC) to LINE_OUT
MONO_OUT
HEADPHONE_OUT (32 Ω load) per channel (peak)
Dynamic Range: -60dB signal level (Note 2)
CD to LINE_OUT
LINE / AUX / VIDEO to LINE_OUT
PCM (DAC) to LINE_OUT
PCM (DAC) in BYPASS Mode to LINE_OUT
LINE_IN to A/D
LINE_IN to HEADPHONE_OUT
Analog Frequency Response (Note 3)
Total Harmonic Distortion + Noise (-3dB): (Note 4)
CD to LINE_OUT
LINE / AUX / VIDEO to LINE_OUT
PCM (DAC) to LINE_OUT (full scale)
PCM (DAC) in BYPASS Mode to LINE_OUT
LINE_IN to A/D (-3dBV input Level)
HEADPHONE_OUT (32 Ω load)
HEADPHONE_OUT (10 k Ω load)
SNR (idle channel) (Note 5)
DAC to LINE_OUT
DAC in BYPASS Mode
LINE / AUX / VIDEO to LINE_OUT
LINE_IN to A/D with High Pass Filter enabled
A/D & D/A Digital Filter Pass Band (Note 6)
A/D & D/A Digital Filter Transition Band
A/D & D/A Digital Filter Stop Band
A/D & D/A Digital Filter Stop Band Rejection (Note 7)
DAC Out-of-Band Rejection (Note 8)
Group Delay (48 KHz sample rate)
Power Supply Rejection Ratio (1 KHz)
IDT™
14
Min
Typ
Max
Unit
-
1.00
0.03
-
Vrms
Vrms
-
0.5
0.5
0.5
12.5
-
Vrms
Vrms
Vrms
mW
75
75
10
85
85
82
83
85
85
-
30,000
dB
dB
dB
dB
dB
dB
Hz
-
-85
-85
-81
-84
-85
-68
-
dB
dB
dB
dB
dB
dB
-
-77
-
dB
75
20
19,200
28,800
-100
-55
-
85
87
86
88
-70
19,200
28,800
1
-
dB
dB
dB
dB
Hz
Hz
Hz
dB
dB
ms
dB
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Parameter
Power Supply Rejection Ratio (20 KHz)
Any Analog Input to LINE_OUT Crosstalk
(10 KHz Signal Frequency)
Any Analog Input to LINE_OUT Crosstalk
(1 KHz Signal Frequency)
Spurious Tone Rejection
Attenuation, Gain Step Size
Input Impedance
Input Capacitance
VREFout
VREF
Interchannel Gain Mismatch ADC
Interchannel Gain Mismatch DAC
Gain Drift
DAC Offset Voltage
Deviation from Linear Phase
LINE_OUT/MONO_OUT Load Resistance
LINE_OUT/MONO_OUT Load Capacitance
HEADPHONE_OUT Load Resistance
HEADPHONE_OUT Load Capacitance
Mute Attenuation
PLL lock time
PLL 24.576 MHz clock jitter
PLL frequency multiplication tolerance
Note:
1.
2.
3.
4.
5.
6.
7.
8.
IDT™
Min
-
Typ
-40
Max
-
Unit
dB
-
-80
-
dB
-
-100
-
dB
10
-
-100
1.5
50
15
0.5 X AVdd
0.41X AVdd
100
10
32
96
100
-
0.5
0.5
20
1
50
100
200
750
12.5
dB
dB
KΩ
pF
V
V
dB
dB
ppm/ºC
mV
degrees
KΩ
pF
Ω
pF
dB
µsec
psec
ppm
With +30 dB Boost on, 1.00 Vrms with Boost off.
Ratio of Full Scale signal to noise output with -60dB signal, measured “A-weighted” over a 20 Hz to a 20 KHz bandwidth.
± 1dB limits for Line Output & 0 dB gain, at -20dBV
Ratio of Full Scale signal to THD+N output with -3dB signal, measured “A-weighted” over a 20 Hz to a 20 KHz bandwidth.
48 KHz Sample Frequency
Ratio of Full Scale signal to idle channel noise output is measured “A-weighted” over a 20 Hz to a 20 KHz bandwidth.
(AES17-1991 Idle Channel Noise or EIAJ CP-307 Signal-to-noise Ratio).
Peak-to-Peak Ripple over Passband meets ± 0.25dB limits, 48 KHz Sample Frequency.
Stop Band rejection determines filter requirements. Out-of-Band rejection determines audible noise.
The integrated Out-of-Band noise generated by the DAC process, during normal PCM audio playback, over a bandwidth
28.8 to 100 KHz, with respect to a 1 Vrms DAC output.
15
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
2.2.
AC Timing Characteristics
(T ambient = 25 °C, AVdd = 3.3 V or 5 V ± 5%, DVdd = 3.3 V ± 5%, AVss=DVss=0 V; 75 pF external
load for BIT_CLK and 60 pF external load for SDATA_IN)
2.2.1.
Cold Reset
Figure 2. Cold Reset Timing
Trst2clk
Tres_low
RESET#
Ttri2actv
BIT_CLK
Ttri2actv
SDATA_IN
Parameter
RESET# active low pulse width
RESET# inactive to SDATA_IN or BIT_CLK active delay
RESET# inactive to BIT_CLK startup delay
BIT_CLK active to RESET# asserted (Not shown in diagram)
Symbol
Tres_low
Tri2actv
Trst2clk
Tclk2rst
Min
1.0
0.01628
0.416
Typ
-
Max
25
400
-
Units
µs
ns
µs
µs
Typ
1.3
-
Max
-
Units
µs
ns
Note: BIT_CLK and SDATA_IN are in a high impedance state during reset.
2.2.2.
Warm Reset
Figure 3. Warm Reset Timing
Tsync_high
Tsync_2clk
SYNC
BIT_CLK
Parameter
SYNC active high pulse width
SYNC inactive to BIT_CLK startup delay
IDT™
Symbol
Tsync_high
Tsync2clk
16
Min
1.0
162.8
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
2.2.3.
Clocks
Figure 4. Clocks Timing
Tclk_low
BIT_CLK
Tclk_high
Tclk_period
Tsync_low
Tsync_high
SYNC
Tsync_period
Parameter
BIT_CLK frequency
BIT_CLK period
BIT_CLK output jitter
BLT_CLK high pulse width (Note 1)
BIT_CLK low pulse width (Note 1)
SYNC frequency
SYNC period
SYNC high pulse width
SYNC low pulse width
Note:
1. Worst case duty cycle restricted to 45/55.
2.2.4.
Symbol
Tclk_period
Tclk_high
Tclk_low
Tsync_period
Tsync_high
Tsync_low
Min
36
36
-
Typ
12.288
81.4
750
40.7
40.7
48.0
20.8
1.3
19.5
Max
45
45
-
Units
MHz
ns
ps
ns
ns
KHz
µs
µs
µs
STAC9752/9753 Crystal Elimination Circuit and Clock Frequencies
The STAC9752/9753 supports several clock frequency inputs as described in the following table. In
general, when a 24.576 MHz crystal is not used, the XTALOUT pin should be tied to ground. This
short to ground configures the part into an alternate clock mode and enables an on board PLL.
CODEC Modes:
P = The STAC9752/9753 as a Primary CODEC.
S = The STAC9752/9753 as a Secondary CODEC.
Table 1. Clock Mode Configuration
XTL_OUT Pin Config CID1 Pin Config CID0 Pin Config
XTAL
float
float
XTAL or open
float
pulldown
XTAL or open
pulldown
float
XTAL or open
pulldown
pulldown
short to ground
float
float
short to ground
float
pulldown
short to ground
pulldown
float
short to ground
pulldown
pulldown
IDT™
17
Clock Source Input
24.576 MHz xtal
12.288 MHz bit clk
12.288 MHz bit clk
12.288 MHz bit clk
14.31818 MHz source
27 MHz source
48 MHz source
24.576 MHz source
CODEC Mode CODEC ID
P
0
S
1
S
2
S
3
P
0
P
0
P
0
P
0
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Table 2. Common Clocks and Sources
2.2.5.
Clock Source
Clock Frequency
XTAL
24.576 MHz
BIT_CLK
VGA
12.288 MHz
14.31818 MHz
Digital Video
27 MHz
USB
48 MHz
Data Setup and Hold
(50 pF external load)
Figure 5. Data Setup and Hold Timing
tco
BIT_CLK
T setup
V ih
V il
SDATA_OUT
SDATA_IN
SYNC
V oh
V ol
T hold
Parameter
Symbol
Min
Typ
Setup to falling edge of BIT_CLK
Tsetup
10
Hold from falling edge of BIT_CLK
Thold
10
Output Valid Data from rising edge of BIT_CLK
tco
Note:
Setup and hold time parameters for SDATA_IN are with respect to the AC'97 controller.
2.2.6.
Max
15
Units
ns
ns
ns
Max
6
6
6
6
Units
ns
ns
ns
ns
Signal Rise and Fall Times
(BIT_CLK: 75 pF external load; from 10% to 90% of Vdd)
(SDATA_IN: 60 pF external load; from 10% to 90% of Vdd)
Figure 6. Signal Rise and Fall Times Timing
BIT_CLK
Triseclk
Tfallclk
Trisedin
Tfalldin
SDATA_IN
Parameter
Symbol
Triseclk
Tfallclk
Trisedin
Tfalldin
BIT_CLK rise time
BIT_CLK fall time
SDATA_IN rise time
SDATA_IN fall time
IDT™
18
Min
-
Typ
-
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
2.2.7.
AC-Link Low Power Mode Timing
Figure 7. AC-Link Low Power Mode Timing
Slot 1
SYNC
Slot 2
BIT_CLK
Write to
0x20
SDATA_OUT
Data PR4
Don't care
Ts2_pdown
SDATA_IN
Note: BIT_CLK not to scale
Parameter
End of Slot 2 to BIT_CLK, SDATA_IN low
2.2.8.
Symbol
Ts2_pdown
Min
-
Typ
-
Max
1.0
Units
µs
Typ
-
Max
25.0
Units
ns
ns
ATE Test Mode
Figure 8. ATE Test Mode Timing
RESET#
SDATA_OUT
Tsetup2rst
Hi-Z
SDATA_IN, BIT_CLK
Toff
Parameter
Setup to trailing edge of RESET# (also applies to SYNC)
Rising edge of RESET# to Hi-Z delay
Note:
1.
2.
3.
IDT™
Symbol
Tsetup2rst
Toff
Min
15.0
-
All AC-Link signals are normally low through the trailing edge of RESET#. Bringing SDATA_OUT high for the trailing edge
of RESET# causes the STAC9752/9753 AC-Link outputs to go high-impedance which is suitable for ATE in circuit testing.
Once the test mode has been entered, the STAC9752/9753 must be issued another RESET# with all AC-Link signals low
to return to the normal operating mode.
The pound sign (#) appended to the end of a signal name denotes that the signal is active low.
19
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
3. TYPICAL CONNECTION DIAGRAM
Figure 9. Typical Connection Diagram
*OPTIONAL
2 Ω*
Ferrite Bead
3.3V ± 5%
0.1 µF
1 µF
0.1 µF
25
AVdd1
0.1 µF
1 µF
38
1
AVdd2
DVdd1
0.1 µF
(Near Clk source)
CLOCK_IN*
9
*Add resistive divider
when using 5V clock.
OPTIONAL
DVdd2
2
27 pF
XTL_IN
24.576 MHz
12
PC_BEEP
XTL_OUT
3
13
PHONE
SDATA_OUT
14
AUX_L
BIT_CLK
AUX_R
SDATA_IN
15
SYNC
16
VIDEO_L
RESET#
27 pF
0Ω
5
22 Ω
6
8
EMI
Filter
27 pF
10
TUNE TO LAYOUT
11
17
VIDEO_R
CID0
18
CID1
CD_L
19
EAPD
STAC9753
CD_GND
VREFOUT
20
CD_R
VREF
45
46
47
28
27
1 µF
21
MIC1
NC
22
MIC2
NC
23
NC
LINE_IN_L
SPDIF
24
LINE_IN_R
GPIO1
32
1 µF*
CAP2
GPIO0
0.1 µF
LINE_OUT_L
*OPTIONAL
LINE_OUT_R
820 pF
820 pF
29
AFILT1
MONO_OUT
HP_OUT_L
30
31
33
34
48
44
43
35
36
37
39
AFILT2
HP_COMM
AVss1
26
AVss2
42
DVss1
DVss2
4
7
HP_OUT_R
40
HP_COMM should be tied to
ground at the headphone pin.
41
*Terminate ground
plane as close to codec
as possible
Analog
Ground
Digital
Ground
Note: Pin 48: To Enable SPDIF, use an 1 KΩ to10 KΩ external pulldown. To Disable SPDIF, use an 1 KΩ
to10 KΩ external pullup. Do NOT leave Pin 48 floating.
Note: The CD_GND signal is an AC signal return for the two CD input channels. It is normally biased at about
2.5 V. The name of the pin in the AC’97 specification is CD_GND, and this has confused many
designers. It should not have any DC path to GND. Connecting the CD_GND signal directly to ground
will change the internal bias of the entire CODEC, and cause serious distortion. If there is no analog CD
input, then this pin can be No-Connect.
IDT™
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
3.1.
Split Independent Power Supply Operation
In PC applications, one power supply input to the STAC9752/9753 may be derived from a supply
regulator and the other directly from the PCI power supply bus. When power is applied to the PC, the
regulated supply input to the IC will be applied some time delay after the PCI power supply. Without
proper on-chip partitioning of the analog and digital circuitry, some manufacturer's CODECs would
be subject to on-chip SCR type latch-up.
IDT’s STAC9752/9753 specifically allows power-up sequencing delays between the analog (AVddx)
and digital (VDddx) supply pins. These two power supplies can power-up independently and at different rates with no adverse effects to the CODEC. The IC is designed with independent analog and
digital circuitry that prevents on-chip SCR type latch-up.
However, the STAC9752/9753 is not designed to operate for extended periods with only the analog
supply active.
IDT™
21
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Figure 10. Split Independent Power Supply Operation
*Suggested
3.3V or 5V ± 5%
0.1 µF
1 µF
0.1 µF
0.1 µF
3.3V ± 5%
10 µF
0.1 µF
(Near Clk source)
25
AVdd1
38
1
AVdd2
DVdd1
CLOCK_IN*
9
*Add resistive divider
when using 5V clock.
OPTIONAL
DVdd2
27 pF
XTL_IN
24.576 MHz
12
PC_BEEP
XTL_OUT
27 pF
0 Ω
13
PHONE
SDATA_OUT
14
AUX_L
BIT_CLK
AUX_R
SDATA_IN
15
SYNC
16
VIDEO_L
RESET#
17
VIDEO_R
CID0
18
CID1
CD_L
STAC9752 (5V Analog)
or
STAC9753 (3.3V Analog)
19
CD_GND
20
CD_R
EAPD
VREFOUT
VREF
21
5
6
22 Ω
8
10
EMI
Filter
27 pF
TUNE TO LAYOUT
11
45
46
47
28
27
1 µF
MIC1
NC
22
MIC2
NC
23
NC
LINE_IN_L
SPDIF
24
LINE_IN_R
GPIO1
32
1 µF*
CAP2
GPIO0
0.1 µF
LINE_OUT_L
*OPTIONAL
LINE_OUT_R
820 pF
820 pF
29
AFILT1
MONO_OUT
HP_OUT_L
30
31
33
34
48
44
43
35
36
37
39
AFILT2
HP_COMM
AVss1
26
AVss2
42
DVss1
4
DVss2
7
HP_OUT_R
40
HP_COMM should be tied to
ground at the headphone pin.
41
*Terminate ground
plane as close to codec
as possible
Analog
Ground
Digital
Ground
Note: Pin 48: To Enable SPDIF, use an 1 KΩ to 10 KΩ external pulldown resistor. To Disable SPDIF, use an
1 KΩ to 10 KΩ external pullup resistor. Do NOT leave Pin 48 floating.
IDT™
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STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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4. CONTROLLER, CODEC AND AC-LINK
This section describes the physical and high-level functional aspects of the AC‘97 Controller to
CODEC interface, referred to as AC-Link.
4.1.
AC-Link Physical Interface
The STAC9752/9753 communicates with its companion Digital Controller via the AC-Link digital
serial interface. AC-Link has been defined to support connections between a single Controller and
up to four CODECs. All digital audio, modem and handset data streams, as well as all control (command/status) information are communicated over this serial interconnect, which consists of a clock
(BIT_CLK), frame synchronization (SYNC), serial data in (SDATA_IN), serial data out
(SDATA_OUT) and a reset (RESET#).
4.2.
Controller to Single CODEC
The simplest and most common AC‘97 system configuration is a point-to-point AC-Link connection
between Controller and the STAC9752/9753, as illustrated in Figure 11.
Figure 11. AC-Link to its Companion Controller
SYNC
XTAL_IN
BIT_CLK
Digital DC'97
Controller
SDATA_OUT
AC'97 Codec
SDATA_IN
XTAL_OUT
RESET#
A primary CODEC may act as either a source or a consumer of the bit clock (BIT_CLK), depending
on the configuration.
While RESET# is asserted, if a clock is present at the BIT_CLK pin for at least five cycles before
RESET# is de-asserted, then the CODEC is a consumer of BIT_CLK, and must not drive BIT_CLK
when RESET# is de-asserted. The clock is being provided by other than the primary CODEC, for
instance by the controller or an independent clock chip. In this case the primary CODEC must act as
a consumer of the BIT_CLK signal as if it were a secondary CODEC.
This clock source detection must be done each time the RESET# line is asserted. In the case of a
warm reset, where the clock is halted but RESET# is not asserted, the CODEC must remember the
clock source, and not begin generating the clock on the assertion of SYNC, if the CODEC had previously determined that it was a consumer of BIT_CLK.
IDT™
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Figure 12. CODEC Clock Source Detection
AC'97 Clock Source
Detection
RESET# Signal Asserted
Yes
12.288MHz signal on BIT_CLK is
being generated externally; codec
uses this signal as the clock.
Yes
24.576MHz Crystal on XTL_IN
and XTL_OUT used by codec to
generate clock on BIT_CLK
Yes
24.576 MHz signal on XTL_IN
used by codec to generate
12.288MHz clock on BIT_CLK
Yes
14.318 MHz signal on XTL_IN
used by codec to generate
12.288MHz clock on BIT_CLK
BIT_CLK Toggling?
No
After RESET# Signal
Deasserted
24.576MHz
crystal present?
No
24.576MHz
oscillator present?
No
14.318MHz
oscillator presnent?
No
Error condition - no clock
source present
The STAC9752/9753 uses the XTAL_OUT Pin (Pin 3) and the CID0 and CID1 pins (Pins 45 & 46) to
determine its alternate clock frequencies. See section 2.2.4: page17 for additional information on
Crystal Elimination and for supported clock frequencies.
If, when the RESET# signal has been de-asserted, the CODEC has not detected a signal on
BIT_CLK as defined in the previous paragraph, then the AC‘97 CODEC derives its clock internally
from an externally attached 24.576 MHz crystal or oscillator, or optionally from an external
14.31 MHz oscillator, and drives a buffered 12.288 MHz clock to its digital companion Controller
over AC-Link under the signal name “BIT_CLK”. Clock jitter at the DACs and ADCs is a fundamental
impediment to high quality output, and the internally generated clock will provide AC‘97 with a clean
clock that is independent of the physical proximity of AC‘97’s companion Digital Controller (henceforth referred to as “the Controller”).
If BIT_CLK begins toggling while the RESET# signal is still asserted, the clock is being provided by
other than the primary CODEC, for instance by the controller or by a discrete clock source. In this
case, the primary CODEC must act as a consumer of the BIT_CLK signal as if it were a secondary
CODEC.
The beginning of all audio sample packets, or Audio Frames, transferred over AC-Link is synchronized to the rising edge of the SYNC signal. SYNC is driven by the Controller. The Controller gener-
IDT™
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ates SYNC by dividing BIT_CLK by 256 and applying some conditioning to tailor its duty cycle. This
yields a 48 KHz SYNC signal whose period defines an audio frame. Data is transitioned on AC-Link
on every rising edge of BIT_CLK, and subsequently sampled by the receiving device on the receiving side of AC-Link on each immediately following falling edge of BIT_CLK.
4.3.
Controller to Multiple CODECs
Several vendor specific methods of supporting multiple CODEC configurations on AC-Link have
been implemented or proposed, including CODECs with selective AC-Link pass-through and controllers with duplicate AC-Links.
Potential implementations include:
•
6-channel audio using 3 x 2-channel CODECs
•
Separate CODECs for independent audio and modem AFE
•
Docking stations, where one CODEC is in the laptop and another is in the dock
This specification defines support for up to four CODECs on the AC-Link. By definition there can be
one Primary CODEC (ID 00) and up to three Secondary CODECs (IDs 01,10, and 11). The CODEC
ID functions as a chip select. Secondary devices therefore have completely orthogonal register sets;
each is individually accessible and they do not share registers.
Multiple CODEC AC-Link implementations must run off a common BIT_CLK. They can potentially
save Controller pins by sharing SYNC, SDATA_OUT, and RESET# from the AC‘97 Digital Controller. Each device requires its own SDATA_IN pin back to the Controller. This prevents contention of
multiple devices on one serial input line.
Support for multiple CODEC operation necessitates a specially designed Controller. An AC‘97 Digital Controller that supports multiple CODEC configurations implements multiple SDATA_IN inputs,
supporting one Primary CODEC and up to three Secondary CODECs.
4.3.1.
Primary CODEC Addressing
Primary AC‘97 CODECs respond to register read and write commands directed to CODEC ID 00
(see Section 10 for details of the Primary and Secondary CODEC addressing protocols). Primary
devices must be configurable (by hardwiring, strap pin(s), or other methods) as CODEC ID 00, and
reflect this in the two-bit CODEC ID field(s) of the Extended Audio and/or Extended Modem ID Register(s).
The Primary CODEC may either drive the BIT_CLK signal or consume a BIT_CLK signal provided
by the digital controller or other clock generator.
4.3.2.
Secondary CODEC Addressing
Secondary AC‘97 CODECs respond to register read and write commands directed to CODEC IDs
01, 10, or 11. Secondary devices must be configurable (via hardwiring, strap pin(s), or other methods) as CODEC IDs 01, 10, or 11 in the two-bit field(s) of the Extended Audio and/or Extended
Modem ID Register(s).
CODECs configured as Secondary must power up with the BIT_CLK pin configured as an input.
Using the provided BIT_CLK signal is necessary to ensure that everything on the AC-Link is synchronous. BIT_CLK is the clock source (multiplied by 2 so that the internal rate is 24.576 MHz).
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4.3.3.
CODEC ID Strapping
Audio CODECs in the 48-pin package use pins 45 and 46 (defined as ID0# and ID1#) as strapping
(i.e. configuration) pins to configure the CODEC ID. The ID0# and ID1# strapping bits adopt inverted
polarity and default to 00 = Primary (via a weak internal pullup) when left floating. This eliminates the
need for external resistors for CODECs configured as Primary, and maintains backward compatibility with existing layouts that treat pins 45 and 46 as “no connect” or cap to ground. Pulldowns are
typically 0-10 kΩ and connected to Digital (not Analog) Ground.
Table 3. Recommended CODEC ID strapping
4.4.
CID1 (pin 46)
CID0 (pin 45)
Configuration
NC
NC
NC
pulldown
Primary ID = 00
Secondary ID = 01
pulldown
NC
Secondary ID = 10
pulldown
pulldown
Secondary ID = 11
Clocking for Multiple CODEC Implementations
To keep the system synchronous, all Primary and Secondary CODEC clocking must be derived from
the same clock source, so all CODECs are operating on the same time base. In addition, all AC-Link
protocol timing must be based on the BIT_CLK signal, to ensure that everything on the AC-Link will
be synchronous.
The following are potential 24.576 MHz clock options available to a Secondary CODEC:
•
Using an external 24.576 MHz signal source (external oscillator or AC‘97 Digital Controller).
•
Using the Primary’s XTAL_OUT.
•
Using the Primary’s BIT_CLK output to derive 24.576 MHz.
See section 2.2.4: page17 for supported clock frequencies and configurations.
4.5.
STAC9752/9753 as a Primary CODEC
Primary devices are required to support correctly any of the following clocking options:
•
24.576 MHz crystal attached to XTAL_IN and XTAL_OUT.
•
24.576 MHz external oscillator provided to XTAL_IN.
•
12.288 MHz oscillator provided to the BIT_CLK input.
The Primary device may also, optionally, support the following clocking option:
•
14.318 MHz external oscillator provided to XTAL_IN.
See section 2.2.4: page17 for supported clock frequencies and configurations.
4.5.1.
STAC9752/9753 as a Secondary CODEC
Secondary devices are required to function correctly using one or more of the following clocking
options:
•
24.576 MHz external oscillator provided to XTAL_IN (synchronous and in phase with Primary
24.576 MHz clock).
•
BIT_CLK input provided by the Primary. In this mode, a clock at XTAL_IN (Pin 2) is ignored.
See section 2.2.4: page17 for supported clock frequencies and configurations.
IDT™
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4.6.
AC-Link Power Management
4.6.1.
Powering down the AC-Link
The AC-Link signals can be placed in a low power mode. When the AC‘97’s Powerdown 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. After signaling a reset to AC‘97, the AC‘97 Controller should not
attempt to play or capture audio data until it has sampled a CODEC Ready indication from AC‘97.
Figure 13. STAC9752/9753 Powerdown Timing
SYNC
BIT_CLK
SDATA_OUT
slot 2
per
frame
TAG
SDATA_IN
slot 2
per
frame
TAG
Write to
0x20
DATA
PR4
Note: BIT_CLK not to scale
BIT_CLK and SDATA_IN are transitioned low immediately following decode of the write to the Powerdown Register (26h) with PR4. When the AC‘97 Controller driver is at the point where it 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.
After programming the AC‘97 device to this low power, halted mode, the AC‘97 Controller is required
to drive and keep SYNC and SDATA_OUT low.
Once the AC‘97 CODEC 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.
4.6.2.
Waking up the AC-Link
There are two methods for bringing 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.
4.6.2.1.
Controller Initiates Wake-up
The AC-Link protocol provides for a “Cold AC‘97 Reset”, and a “Warm AC‘97 Reset”. The current
powerdown state ultimately dictates which form of AC‘97 reset is appropriate. Unless a “cold” or
“register” reset (a write to the Reset Register) is performed, wherein the AC‘97 registers are initialized to their default values, registers are required to keep state during all powerdown modes.
Once powered down, re-activation of the AC-Link via re-assertion of the SYNC signal must not occur
for a minimum of four audio frame times following the frame in which the powerdown was triggered.
When AC-Link powers up, the CODEC indicates readiness via the CODEC Ready bit (input slot 0,
bit 15).
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4.6.2.2.
CODEC Initiates Wake-up
The STAC9752/9753 (running off Vaux) can trigger a wake event (PME#) by transitioning
SDATA_IN from low to high and holding it high until either a warm or cold reset is observed on the
AC-Link. This functionality is typically implemented in modem CODECs that detect ring, Caller ID,
etc.
Note that when the AC-Link is either programmed to the low power mode or shut off completely,
BIT_CLK may stop if the primary CODEC is supplying the clock, which shuts down the AC-Link
clock to the Secondary CODEC1. In order for a Secondary CODEC to react to an external event
(phone ringing), it must support an independent clocking scheme for any PME# associated logic that
must be kept alive when the AC-Link is down. This includes logic to asynchronously drive
SDATA_IN to a logic high-level which signals a wake request to the AC‘97 Digital Controller.
4.6.3.
CODEC Reset
There are three types of AC‘97 reset:
•
a cold reset where all AC‘97 logic (most registers included) is initialized to its default state
•
a warm reset where the contents of the AC‘97 register set are left unaltered
•
a register reset which only initializes the AC‘97 registers to their default states
4.6.3.1.
Cold AC‘97 Reset
A cold reset is achieved by asserting RESET# (low) for the minimum specified time, then subsequently de-asserting RESET# (high). BIT_CLK and SDATA_IN will be activated, or re-activated as
the case may be, and all AC‘97 control registers will be initialized to their default power on reset values.
RESET# is an asynchronous AC‘97 input.
4.6.3.2.
Warm AC‘97 Reset
A warm AC‘97 reset will re-activate the AC-Link without altering the current AC‘97 register values. A
warm reset is signaled by driving SYNC high for a minimum of 1 µs in the absence of BIT_CLK.
Within normal audio frames, SYNC is a synchronous AC‘97 input. However, in the absence of
BIT_CLK, SYNC is treated as an asynchronous input used in the generation of a warm reset to
AC‘97.
AC‘97 MUST NOT respond with the activation of BIT_CLK until SYNC has been sampled low again
by AC‘97. This will preclude the false detection of a new audio frame.
4.6.3.3.
Register AC‘97 Reset
Most registers in an AC device can be restored to their default values by performing a write (any
value) to the Reset Register, 00h.
1.
IDT™
Secondary CODECs always configure the BIT_CLK pin as an input.
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5. AC-LINK DIGITAL INTERFACE
5.1.
Overview
AC-Link is the 5 pin digital serial interface that links the AC‘97 CODEC to the Controller. The
AC-Link protocol is a bi-directional, fixed clock rate, serial digital stream. AC-Link handles multiple
input and output PCM audio streams, as well as control register accesses employing a time division
multiplexed (TDM) scheme that divides each audio frame into 12 outgoing and 12 incoming data
streams, each with 20-bit sample resolution.
The STAC9752/9753 DACs, ADCs, and SPDIF can be assigned to slots 3&4, 6&9, 7&8 or 10&11.
Figure 14. Bi-directional AC-Link Frame with Slot assignments
SLOTS
0
1
2
3
4
5
6
7
8
9
10
11
12
TAG
CMD
ADDR
CMD
DATA
PCM
LEFT
PCM
RT
NA
PCM
CTR
PCM
LSURR
PCM
RSURR
PCM
LFE
SPDIF
SPDIF
IO
CTRL
TAG
STATUS
ADDR
STATUS
DATA
PCM
LEFT
PCM
RT
LINE1
ADC
PCM
MIC
Vendor
RSVD
Vendor
RSVD
Vendor
RSVD
LINE2
ADC
HSET
ADC
IO
STATUS
SYNC
OUTGOING STREAMS
(Controller output - SDATA_OUT)
INCOMING STREAMS
(codec output - SDATA_IN)
TAG PHASE
DATA PHASE
Slot 12 can be used by the
AC'97 Codec if a Modem
Codec is not present.
Table 4. AC-Link output slots (transmitted from the Controller)
Slot
Name
Description
0
SDATA_OUT TAG
MSBs indicate which slots contain valid data; LSBs convey
CODEC ID
1
Control CMD ADDR write port
Read/write command bit plus 7-bit CODEC register address
2
3, 4
Control DATA write port
PCM L&R DAC playback
16-bit command register write data
20-bit PCM data for Left and Right channels
5
Modem Line 1 DAC
16-bit modem data for modem Line 1 output
6, 7, 8, 9 PCM Center, Surround L&R, LFE 20-bit PCM data for Center, Surround L&R, LFE channels
10
Modem Line 2 DAC
16-bit modem data for modem Line 2 output
IDT™
11
Modem handset DAC
12
12
Modem I/O control
CODEC IRQ
10-11
SPDIF Out
10-12
Double rate audio
16-bit modem data for modem Handset output
GPIO write port for modem Control
Can be used by CODEC if a modem CODEC is not present.
Optional AC-Link bandwidth for SPDIF output
Optional AC-Link bandwidth for 88.2 KHz or 96 KHz on L, C, R
channels
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Table 5. The AC-Link input slots (transmitted from the CODEC)
5.2.
Slot
Name
0
1
SDATA_IN TAG
STATUS ADDR read port
MSBs indicate which slots contain valid data
MSBs echo register address; LSBs indicate which slots request data
Description
2
STATUS DATA read port
16-bit command register read data
3, 4
5
PCM L&R ADC record
Modem Line 1 ADC
20-bit PCM data from Left and Right inputs
16-bit modem data from modem Line1 input
6-11
PCM ADC Record
20-bit PCM data - Alternative Slots for Input
12
GPIO Status
GPIO read port and interrupt status
AC-Link Serial Interface Protocol
The AC‘97 Controller signals synchronization of all AC-Link data transactions. The AC‘97 CODEC,
Controller, or external clock source drives the serial bit clock (BIT_CLK) onto AC-Link, which the
AC‘97 Controller then qualifies with a synchronization signal (SYNC) to construct audio frames.
SYNC, fixed at 48 KHz, is derived by dividing down the serial bit 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 is transitioned on each rising edge of BIT_CLK. The receiver of
AC-Link data (CODEC for outgoing data and Controller for incoming data) samples each serial bit on
the falling edges of BIT_CLK.
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 source of the
data (AC‘97 CODEC for the input stream, AC‘97 Controller for the output stream), to stuff all bit positions with 0 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, for power savings, all clock, sync, and data signals can be halted. This requires that an
AC‘97 CODEC be implemented as a static design to allow its register contents to remain intact when
entering a power savings mode.
5.2.1.
AC-Link Variable Sample Rate Operation
The AC-Link serial interconnect defines a digital data and control pipe between the Controller and
the CODEC. The AC-Link supports 12 20-bit slots at 48 KHz on SDATA_IN and SDATA_OUT. The
time division multiplexed (TDM) “slot-based” architecture supports a per-slot valid tag infrastructure
that the source of each slot’s data sets or clears to indicate the validity of the slot data within the current audio frame. This tag infrastructure can be used to support transfers between Controller and
CODEC at any sample rate.
5.2.2.
Variable Sample Rate Signaling Protocol
AC-Link’s tag infrastructure imposes FIFO requirements on both sides of the AC-Link. For example,
in passing a 44.1 KHz stream across the AC-Link, for every 480 audio output frames that are sent
across, 441 of them must contain valid sample data. Does the AC‘97 Digital Controller pass all 441
PCM samples followed by 39 invalid slots? Or does the AC‘97 Digital Controller evenly interleave
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valid and non-valid slots? Each possible method brings with it different FIFO requirements. To
achieve interoperability between AC‘97 Digital Controllers and CODECs designed by different manufacturers, it is necessary to standardize the scheme for at least one side of the AC-Link so that the
FIFO requirements will be common to all designs. The CODEC side of the AC-Link is the focus of
this standardization.
The new standard approach calls for the addition of “on demand” slot request flags. These flags are
passed from the CODEC to the AC‘97 Digital Controller during every audio input frame. Each time
the AC‘97 Digital Controller sees one or more of the newly-defined slot request flags set active (low)
in a given audio input frame, it knows that it must pass along the next PCM sample for the corresponding slot(s) in the AC-Link output frame that immediately follows.
The VRA (Variable Rate Audio) bit in the Extended Audio Status and Control Register must be set to
1 to enable variable sample rate audio operation. Setting the VRA = 1 has two functions:
1.
Enables PCM DAC/ADC conversions at variable sample rates by write enabling Sample Rate
Registers 2Ch through 34h.
2.
Enables the on demand CODEC-to-Controller signaling protocol using SLOTREQ bits that
becomes necessary when a DAC’s sample rate varies from the 48 KHz AC-Link serial frame
rate.
The table below summarizes the behavior:
Table 6. VRA Behavior
AC‘97 Functionality
SLOTREQ bits
VRA = 0
always 0 (data each frame)
VRA = 1
0 or 1 (data on demand)
sample rate registers
forced to 48KHz
writable
Note: If more than one CODEC is being used with the SAME controller DMA engine, VRA should NOT be
used.
For variable sample rate output, the CODEC examines its sample rate control registers, the state of
its FIFOs, and the incoming SDATA_OUT tag bits at the beginning of each AC-Link output frame to
determine which SLOTREQ bits to set active (low). SLOTREQ bits asserted during the current
AC-Link input frame signal which active output slots require data from the AC‘97 Digital Controller in
the next audio output frame. An active output slot is defined as any slot supported by the CODEC
that is not in a power-down state. For fixed 48KHz operation the SLOTREQ bits are always set
active (low) and a sample is transferred in each frame.
For variable sample rate input, the tag bit for each input slot indicates whether valid data is present
or not. Thus, even in variable sample rate mode, the CODEC is always the master: for SDATA_IN
(CODEC to Controller), the CODEC sets the TAG bit; for SDATA_OUT (Controller to CODEC), the
CODEC sets the SLOTREQ bit and then checks for the TAG bit in the next frame.
The VRM (Variable Rate Microphone Audio) bit in the Extended Audio Status and Control Register
controls the optional MIC ADC input behavior in the same way that VRA = 1 controls the PCM ADC.
5.2.2.1.
SLOTREQ Behavior and Power Management
SLOTREQ bits for fixed rate, powered down, and all unsupported Slots should be driven low (zero)
for maximum compatibility with the original AC'97 Component Specification. When a DAC channel is
powered down, it disappears completely from the serial frame: output tag and slot are ignored, and
the SLOTREQ bit is absent (forced to zero).
When the Controller wants to power-down a channel, all it needs to do is:
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1.
Disable source of DAC samples in Controller
2.
Set PR bit for DAC channel in Registers 26h, 2Ah, or 3Eh
When it wants to power up the channel, all it needs to do is:
5.2.3.
1.
Clear PR bit for DAC channel in Registers 26h, 2Ah, or 3Eh
2.
Enable source of DAC samples in Controller
Primary and Secondary CODEC Register Addressing
The 2-bit CODEC ID field in the LSBs of Output Slot 0 is an addition to the original AC-Link protocol
that enables an AC‘97 Digital Controller to independently access Primary and Secondary CODEC
registers.
For Primary CODEC access, the AC‘97 Digital Controller:
1.
Sets the AC-Link Frame valid bit (Slot 0, bit 15)
2.
Validates the tag bits for Slot 1 and 2 Command Address and Data (Slot 0, bits 14 and 13)
3.
Sets a zero value (00) into the CODEC ID field (Slot 0, bits 1 and 0)
4.
Transmits the desired Primary CODEC Command Address and Command Data in Slots 1 and 2
For Secondary CODEC access, the AC‘97 Digital Controller:
1.
Sets the AC-Link Frame valid bit (Slot 0, bit 15)
2.
Places a non-zero value (01, 10, or 11) into the CODEC ID field (Slot 0, bits 1 and 0)
3.
Transmits the desired Secondary CODEC Command Address and Command Data in Slots 1
and 2
Secondary CODECs disregard the Command Address and Command Data (Slot 0, bits 14 and 13)
tag bits. In a sense the Secondary CODEC ID field functions as an alternative Valid Command
Address (for Secondary reads and writes) and Command Data (for Secondary writes) tag indicator.
Secondary CODECs must monitor the Frame Valid bit, and ignore the frame (regardless of the state
of the Secondary CODEC ID bits) if it is not valid. AC‘97 Digital Controllers should set the frame valid
bit for a frame with a Secondary register access, even if no other bits in the output tag slot except the
Secondary CODEC ID bits are set.
5.3.
AC-Link Output Frame (SDATA_OUT)
The AC-Link output frame data streams correspond to the multiplexed bundles of all digital output
data targeting AC‘97’s DAC inputs and control registers. As mentioned earlier, each AC-Link output
frame supports up to 12 20-bit outgoing data time slots. Slot 0 is a special reserved time slot containing 16-bits which are used for AC-Link protocol infrastructure.
Figure 15 illustrates the time slot based AC-Link protocol.
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Figure 15. AC-Link Audio Output Frame
Data Phase
Tag Phase
SYNC
20.8 uS (48 kHZ)
12.288 MHz
BIT_CLK
SDATA_OUT
valid
Frame
slot1
slot2
slot(12)
"0"
CID1 CID0
19
"0"
19
"0"
19
"0"
19
"0"
End of previous audio frame
Time Slot "Valid" Bits
("1" = time slot contains valid PCM data)
Slot 1
Slot 2
Slot 3
Slot 12
A new AC-Link output frame begins with a low to high transition of SYNC. SYNC is synchronous to
the rising edge of BIT_CLK. On the immediately following falling edge of BIT_CLK, the AC‘97
CODEC samples the assertion of SYNC. This falling edge marks the time when both sides of
AC-Link are aware of the start of a new audio frame. On the next rising of BIT_CLK, the AC‘97 Controller transitions SDATA_OUT into the first bit position of slot 0 (Valid Frame bit). Each new bit position is presented to AC-Link on a rising edge of BIT_CLK, and subsequently sampled by the AC‘97
CODEC 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.
Figure 16. Start of an Audio Output Frame
SYNC
asserted
SYNC
detected by
codec
first
SDATA_OUT
bit of frame
SYNC
BIT_CLK
valid
Frame
SDATA_OUT
slot1
slot2
End of previous audio frame
SDATA_OUT’s composite stream is sent MSB first, with all non-valid slots bit positions stuffed with 0
by the AC‘97 Controller. If there are less than 20 valid bits within an assigned and valid time slot, the
AC‘97 Controller always stuffs the trailing non-valid bit positions of the 20-bit slot with 0.
As an example, consider an 8-bit sample stream that is being played out to one of the STAC9752/
9753 DACs. The first 8 bit-positions are presented to the DAC (MSB first) followed by the next 12
bit-positions which are stuffed with 0 by the AC‘97 Controller. This ensures that regardless of the
resolution of the implemented DAC (16, 18 or 20-bit), no DC biasing will be introduced by the least
significant bits.
When mono audio sample streams are output from the AC‘97 Controller, it is necessary that BOTH
left and right sample stream time slots be filled with the same data.
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5.3.1.
Slot 0: TAG / CODEC ID
Table 7. Output Slot 0 Bit Definitions
Bit
Description
15
Frame Valid
14
13
Slot 1 Primary CODEC Valid Command Address bit (Primary CODEC only)
Slot 2 Primary CODEC Valid Command Data bit (Primary CODEC only)
Slot 3-12 Valid Data bits
12
11
Slot 3: PCM Left channel
Slot 4: PCM Right channel
10
Slot 5: Modem Line 1 (not used on STAC9752/9753)
9
8
Slot 6: Alternative PCM1 Left
Slot 7: Alternative PCM2 Left
7
Slot 8: Alternative PCM2 Right
6
5
Slot 9: Alternative PCM1 Right
Slot 10: SPDIF Left
4
Slot 11: SPDIF Right
3
2
1-0
Slot 12: Audio GPIO
Reserved (Set to 0)
2-bit CODEC ID field (00 reserved for Primary; 01, 10, 11 indicate Secondary)
Note: The DAC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
Within slot 0, the first bit is a global bit (SDATA_OUT slot 0, bit 15) which flags the validity for the
entire audio frame. If the “Valid Frame” bit is a 1, this indicates that the current audio frame contains
at least one time slot of valid data. The next 12 bit positions sampled by AC‘97 indicate which of the
corresponding 12 time slots contain valid data. In this way data streams of differing sample rates can
be transmitted across AC-Link at its fixed 48 KHz audio frame rate.
The two LSBs of Slot 0 transmit the CODEC ID used to distinguish Primary and Secondary CODEC
register access.
5.3.2.
Slot 1: Command Address Port
The command port is used to control features and monitor status (see AC-Link input frame Slots 1
and 2) for AC‘97 CODEC functions including, but not limited to, mixer settings, and power management (refer to the control register section of this specification).
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 currently defined, odd register (01h,
03h, etc.) accesses are reserved for future expansion.
Note that shadowing of the control register file on the AC‘97 Controller is an option left open to the
implementation of the AC‘97 Controller. The AC‘97 CODEC’s control register file is nonetheless
required to be readable as well as writeable to provide more robust testability.
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AC-Link output frame slot 1 communicates control register address, and write/read command information to the STAC9752/9753.
Table 8. Command Address Port Bit Assignments
Bit
Description
19
18:12
Read/Write command
Control Register Index
11:0
Reserved
Comments
1= read, 0 = write
Sixty-four 16-bit locations, addressed on even byte boundaries
Stuffed with 0
The first bit (MSB) sampled by AC‘97 indicates whether the current control transaction is a read or a
write operation. The following 7 bit positions communicate the targeted control register address. The
trailing 12 bit positions within the slot are reserved and must be stuffed with 0 by the AC‘97 Controller.
5.3.3.
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 0 if current operation is a read)
•
Bit(3:0) Reserved (Stuffed with 0)
If the current command port operation is a read then the entire slot time must be stuffed with 0 by the
AC‘97 Controller.
5.3.4.
Slot 3: PCM Playback Left Channel
AC-Link 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 (on the
AC‘97 Controller or host processor) with music synthesis output samples. If a sample stream of resolution less than 20-bits is transferred, the AC‘97 Controller must stuff all trailing non-valid bit positions within this time slot with 0.
The DAC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
5.3.5.
Slot 4: PCM Playback Right Channel
AC-Link 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 of resolution less than 20-bits is transferred, the AC‘97 Controller must stuff all trailing non-valid bit positions within this time slot with 0.
The DAC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
5.3.6.
Slot 5: Modem Line 1 Output Channel
Audio output frame slot 5 is reserved for modem operation and is not used by the STAC9752/9753.
5.3.7.
Slot 6 - 11: DAC
The DAC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
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5.3.8.
Slot 12: Audio GPIO Control Channel
AC-Link output frame slot 12 contains the audio GPIO control outputs.
5.4.
AC-Link Input Frame (SDATA_IN)
The AC-Link input frame data streams correspond to the multiplexed bundles of all digital input data
targeting the AC‘97 Controller. As is the case for audio output frame, each AC-Link input frame consists of 12 20-bit time slots. Slot 0 is a special reserved time slot containing 16-bits which are used
for AC-Link protocol infrastructure.
The following diagram illustrates the time slot-based AC-Link protocol.
Figure 17. STAC9752/9753 Audio Input Frame
Data Phase
Tag Phase
SYNC
20.8 uS (48 kHZ)
12.288 MHz
BIT_CLK
valid
Frame
SDATA_IN
slot1
slot2
slot(12)
"0"
"0"
"0"
19
"0"
19
"0"
19
"0"
19
"0"
End of previous audio frame
Time Slot "Valid" Bits
("1" = time slot contains valid PCM data)
Slot 1
Slot 2
Slot 3
Slot 12
A new AC-Link input frame begins with a low to high transition of SYNC. SYNC is synchronous to
the rising edge of BIT_CLK. On the immediately following falling edge of BIT_CLK, the AC‘97
CODEC samples the assertion of SYNC. This falling edge marks the time when both sides of
AC-Link are aware of the start of a new audio frame. On the next rising of BIT_CLK, the AC‘97
CODEC transitions SDATA_IN into the first bit position of slot 0 (“CODEC Ready” bit). Each new bit
position is presented to AC-Link on a rising edge of BIT_CLK, and subsequently sampled by the
AC‘97 Controller on the 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.
Figure 18. Start of an Audio Input Frame
S Y N C
detected
first
S D A T A _ O U T
bit of frame
S Y N C
B I T _ C L K
C o d e c
R e a d y
S D A T A _ IN
slot1
slot2
End of previous audio frame
SDATA_IN’s composite stream is MSB first with all non-valid bit positions (for assigned and/or unassigned time slots) stuffed with 0 by the AC‘97 CODEC. SDATA_IN data is sampled on the falling
edges of BIT_CLK.
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5.4.1.
Slot 0: TAG
Within slot 0 the first bit is a global bit (SDATA_IN slot 0, bit 15) which flags whether the AC‘97
CODEC is in the “CODEC Ready” state or not. If the “CODEC Ready” bit is a 0, this indicates that
the AC‘97 CODEC is not ready for normal operation. This condition is normal following the deassertion of power-on-reset for example, while the AC‘97 CODEC’s voltage references settle. When the
AC-Link “CODEC Ready” indicator bit is a 1, it indicates that the AC-Link and AC‘97 CODEC control
and status registers are in a fully operational state. The CODEC must assert “CODEC Ready” within
400 µs after it starts receiving valid SYNC pulses from the controller, to provide indication of connection to the link and Control/Status registers are available for access. The AC‘97 Controller and
related software must wait until all of the lower four bits of the Control/Status Register, 26h, are set
before attempting any register writes, or attempting to enable any audio stream, to avoid undesirable
audio artifacts.
Prior to any attempts at putting an AC‘97 CODEC into operation, the AC‘97 Controller should poll the
first bit in the AC-Link input frame (SDATA_IN slot 0, bit 15) for an indication that CODEC has gone
“CODEC Ready”. Once an AC‘97 CODEC is sampled “CODEC Ready” 1 , then 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 whether they contain valid data.
5.4.2.
Slot 1: Status Address Port / SLOTREQ signalling bits
5.4.2.1.
Status Address Port
The status port is used to monitor status for the STAC9752/9753 functions including, but not limited
to, mixer settings and power management. AC-Link input frame slot 1’s stream echoes the control
register index, for historical reference, for the data to be returned in slot 2 (assuming that slots 1 and
2 had been tagged “valid” by the AC‘97 CODEC during slot 0).
Table 9. Status Address Port Bit Assignments
Bit
Description
Comments
19
18:12
Reserved
Control Register Index
11:2
SLOTREQ
See Next Section
1:0
Reserved
Stuffed with 0
Stuffed with 0
Echo of register index for which data is being returned
The first bit (MSB) generated by AC‘97 is always stuffed with a 0. The following 7 bit positions communicate the associated control register address, the next 10 bits support AC‘97’s variable sample
rate signaling protocol, and the trailing 2 bit positions are stuffed with 0 by AC‘97.
5.4.2.2.
SLOTREQ signaling bits
AC-Link input frame Slot #1, the Status Address Port, now delivers CODEC control register read
address and variable sample rate slot request flags for all output slots. Ten of the formerly reserved
least significant bits have been defined as data request flags for output slots 3-12.
1. There are several subsections within an AC‘97 CODEC that can independently go busy/ready. It is the responsibility
of the AC’97 Controller to probe more deeply into the AC‘97 CODEC’s register file to determine which subsections
are actually ready.
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The AC-Link input frame Slot 1 tag bit is independent of the bit 11-2 slot request field, and ONLY
indicates valid Status Address Port data (Control Register Index). The CODEC should only set
SDATA_IN tag bits for Slot 1 (Address) and Slot 2 (Data) to 1 when returning valid data from a previous register read. They should otherwise be set to 0. SLOTREQ bits have validity independent of the
Slot 1 tag bit.
SLOTREQ bits are always 0 in the following cases:
•
fixed rate mode (VRA = 0)
•
inactive (powered down) ADC channel
SLOTREQ bits are only set to 1 by the CODEC in the following case:
•
5.4.3.
Variable rate audio mode (VRA = 1) AND active (power ready) ADC AND a non-48 KHz ADC
sample rate AND CODEC does not need a sample
Slot 2: Status Data Port
The status data port delivers 16-bit control register read data.
Table 10. Status Data Port Bit Assignments
Bit
Description
Comments
19:4
Control Register Read Data
3:0
Reserved
Stuffed with 0 if tagged “invalid”
Stuffed with 0
If Slot 2 is tagged invalid by AC‘97, then the entire slot will be stuffed with 0 by AC‘97.
5.4.4.
Slot 3: PCM Record Left Channel
Audio input frame slot 3 is the left channel output of STAC9752/9753 input MUX, post-ADC.
STAC9752/9753 ADCs are implemented to support 20-bit resolution.
NOTE: The ADC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
5.4.5.
Slot 4: PCM Record Right Channel
Audio input frame slot 4 is the right channel output of STAC9752/9753 input MUX, post-ADC.
STAC9752/9753 ADCs are implemented to support 20-bit resolution.
NOTE: The ADC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
5.4.6.
Slot 5: Modem Line 1 ADC
Audio input frame slot 5 is not used by the STAC9752/9753 and is always stuffed with 0.
5.4.7.
Slot 6 - 9: ADC
The left and right ADC channels of the STAC9752/9753 may be assigned to slots 6&9 by Register
6Eh.
NOTE: The ADC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
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5.4.8.
Slots 7 & 8: Vendor Reserved
The left and right ADC channels of the STAC9752/9753 may be assigned to slots 7&8 by Register
6Eh.
NOTE: The ADC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
5.4.9.
Slot 10 & 11: ADC
The left and right ADC channels of the STAC9752/9753 may be assigned to slots 10&11 by Register
6Eh.
NOTE: The ADC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
5.4.10.
Slot 12: Reserved
AC-Link input frame slot 12 contains the GPIO status inputs and allows for audio interrupts. Slot 12
can not be used by the AC’97 CODEC because a modem CODEC is not present.
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5.5.
AC-Link Interoperability Requirements and Recommendations
5.5.1.
“Atomic slot” Treatment of Slot 1 Address and Slot 2 Data
Command or Status Address and Data cannot be split across multiple AC-Link frames. The following
transactions require that valid Slot 1 Address and valid Slot 2 Data be treated as “atomic” (inseparable) with Slot 0 Tag bits for Address and Data set accordingly (that is, both valid):
1.
AC‘97 Digital Controller write commands to Primary CODECs
2.
AC‘97 CODEC status responses
Whenever the AC‘97 Digital Controller addresses a Primary CODEC or an AC‘97 CODEC responds
to a read command, Slot 0 Tag bits should always be set to indicate actual Slot 1 and Slot 2 data
validity.
Table 11. Primary CODEC Addressing: Slot 0 Tag Bits
Function
Slot 0, bit 15
(Valid
Frame)
Slot 0, bit 14
(Valid Slot 1
Address)
AC‘97 Digital Controller Primary
Read Frame N, SDATA_OUT
1
1
0
00
1
1
1
00
1
1
1
00
AC‘97 Digital Controller Primary
Write Frame N, SDATA_OUT
AC‘97 CODEC Status Frame
N+1, SDATA_IN
Slot 0, bit 13
Slot 0, Bits 1-0
(Valid Slot 2 Data)
(CODEC ID)
When the AC‘97 Digital Controller addresses a Secondary CODEC, the Slot 0 Tag bits for Address
and Data must be 0. A non-zero, 2-bit CODEC ID in the LSBs of Slot 0 indicates a valid Read or
Write Address in Slot 1, and the Slot 1 R/W bit indicates presence or absence of valid Data in Slot 2.
Table 12. Secondary CODEC Addressing: Slot 0 Tag Bits
Slot 0, bit 15
(Valid
Frame)
Slot 0, bit 14
(Valid Slot 1
Address)
Slot 0, bit 13
(Valid Slot 2
Data)
Slot 0, Bits
1-0
(CODEC ID)
AC‘97 Digital Controller
Secondary Read Frame N,
SDATA_OUT
1
0
0
01, 10, or 11
AC‘97 Digital Controller
Secondary Write Frame N,
SDATA_OUT
1
0
0
01, 10, or 11
AC‘97 CODEC Status Frame N+1,
SDATA_IN
1
1
1
00
Function
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5.6.
Slot Assignments for Audio
Figure 19. Bi-directional AC-Link Frame with Slot assignments
SLOTS
0
1
2
3
4
5
6
7
8
9
10
11
12
TAG
CMD
ADDR
CMD
DATA
PCM
LEFT
PCM
RT
NA
PCM
CTR
PCM
LSURR
PCM
RSURR
PCM
LFE
SPDIF
SPDIF
IO
CTRL
TAG
STATUS
ADDR
STATUS
DATA
PCM
LEFT
PCM
RT
LINE1
ADC
PCM
MIC
Vendor
RSVD
Vendor
RSVD
Vendor
RSVD
LINE2
ADC
HSET
ADC
IO
STATUS
SYNC
OUTGOING STREAMS
(Controller output - SDATA_OUT)
INCOMING STREAMS
(codec output - SDATA_IN)
TAG PHASE
DATA PHASE
Slot 12 can be used by the
AC'97 Codec if a Modem
Codec is not present.
Note: The DAC & ADC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
The AC-Link output slots dedicated to audio are defined as follows:
Table 13. AC-Link Slot Definitions
Slot
Name
Description
3
PCM L DAC playback
20-bit PCM data for Left channel
4
6
PCM R DAC playback
PCM Center
20-bit PCM data for Right channel
20-bit PCM data for Center channel
7
PCM L Surround
20-bit PCM data for L Surround channel
8
9
PCM R Surround
PCM LFE
20-bit PCM data for R Surround channel
20-bit PCM data for LFE channel
10:11
SPDIF Out
20-bit SPDIF Output
12
Reserved
Reserved
The AC-Link input slots dedicated to audio are defined as follows:
Table 14. AC-Link Input Slots Dedicated To Audio
Slot
Name
3
PCM L ADC record
4
6
Description
20-bit PCM data from Left input
PCM R ADC record
20-bit PCM data from Right inputs
Dedicated Microphone ADC 20-bit PCM data from optional 3rd ADC input
7
Vendor reserved
Vendor specific (enhanced input for docking, array mic, etc.)
8
9
Vendor reserved
Vendor reserved
Vendor specific (enhanced input for docking, array mic, etc.)
Vendor specific (enhanced input for docking, array mic, etc.)
12
Audio Interrupt
Provides optional interrupt capability for Audio CODEC (not usable when
a modem is present)
Note: The ADC can be assigned to slots 3&4, 6&9, 7&8, or 10&11.
IDT™
41
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Table 15. Audio Interrupt Slot Definitions
Bit
Description
19-1 Reserved (Audio CODEC will return zeros in bits 19-1)
0
IDT™
Optional: Assertion = 1 will cause interrupt to be propagated to Audio controller system interrupt. See
register 24h definition for enabling mechanism.
42
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6. STAC9752/9753 MIXER
The STAC9752/9753 includes an analog mixer for maximum flexibility. The analog mixer is designed
to the AC'97 specification to manage the playback and record of all digital and analog audio sources
in the PC environment. The analog mixer also includes several extensions of the AC’97 specification
to support “all analog record” capability as well as “POP BYPASS” mode for all digital playback. The
analog sources include:
•
System Audio: digital PCM input and output for business, games & multimedia
•
CD/DVD: analog CD/DVD-ROM audio with internal connections to CODEC mixer
•
Mono microphone: choice of desktop microphone, with programmable boost and gain
•
Speakerphone: use of system microphone and speakers for telephone, DSVD, and video conferencing
•
Video: TV tuner or video capture card with internal connections to CODEC mixer
•
AUX/synth: analog FM or wavetable synthesizer, or other internal source
•
Line in: external analog line level source from consumer audio, video camera, etc.
Source
PC_BEEP
Function
PC BEEP pass through to LINE_OUT
Connection
from PC_BEEP output
PHONE
MONO input
from telephony subsystem
MIC1
MIC2
desktop microphone
second microphone
from microphone jack
from second microphone jack
LINE_IN
external audio source
from line-in jack
CD
VIDEO
audio from CD-ROM
audio from TV tuner or video camera
cable from CD-ROM
cable from TV or VidCap card
AUX
upgrade synth or other external source
internal connector
PCM_OUT
digital audio output from AC'97 Controller
AC-Link
Destination
IDT™
Function
Connection
HP_OUT
LINE_OUT
stereo mix of all sources
stereo mix of all sources
To headphone out jack
To output jack
MONO_OUT
microphone or MONO Analog mixer output
to telephony subsystem
PCM_IN
SPDIF
digital data from the CODEC to the AC'97 Controller
SPDIF digital audio output
AC-Link
To SPDIF output connector
43
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
7. MIXER FUNCTIONAL DIAGRAMS
Figure 20. STAC9752 2-Channel Mixer Functional Diagram
KEY
MonoAnalog
2Ah:D5-D4
Slot
Select
28h: D5-D4
PCM to
SPDIF
MUX
PCMOut
StereoAnalog
6Ah:D1
Slot
Select
20h:D13
22h:D2-D3
18h
DAC
vol
0Ah
PC_BEEP
0Ch
Phone
Analog
Audio
vol
mute
vol
mute
0Eh:D6 & 6E:D2
MIC1
MIC2
0Eh
10, 20 or
30 dB
10h
LINEIN
12h
CD
16h
AUX
14h
mute
vol
mute
vol
mute
vol
vol
mute
mute
Headphone
Volume
HP_OUT
02h
Σ
20h:D13
22h:D2-D3
3D
Σ
20h:D15
Master
Volume
-6dB
LINE_OUT
06h
MUX
Σ
6Eh:D12
AllAnalog
vs
AllRecord
Mono
Volume
MONO_OUT
1Ah
-6dB
20h:D9
Σ
1Ch
MUX
VIDEO
vol
04h
Digital
PCBeep
MUX
Sources
mute 3D
MUX
20h:D8
Digital
SPDIF
Record
Volume ADC
38h:D5-D4
Slot
Select
PCMIn
ADCRecord
Figure 21. STAC9753 2-Channel Mixer Functional Diagram
KEY
MonoAnalog
2Ah:D5-D4
Slot
Select
28h: D5-D4
PCM to
SPDIF
MUX
PCMOut
StereoAnalog
6Ah:D1
Slot
Select
20h:D13
22h:D2-D3
18h
DAC
0Ah
PC_BEEP
0Ch
Phone
LINEIN
CD
AUX
mute
vol
mute
0Eh
10h
12h
16h
14h
vol
mute
vol
mute
vol
mute
vol
mute
vol
mute
HP_OUT
02h
Σ
0Eh:D6 & 6E:D2
10, 20 or
30 dB
Headphone
Volume
20h:D13
22h:D2-D3
3D
Σ
20h:D15
Master
Volume
-6dB
LINE_OUT
06h
MUX
Σ
6Eh:D12
AllAnalog
vs
AllRecord
Mono
Volume
MONO_OUT
1Ah
-6dB
Σ
20h:D9
MUX
VIDEO
vol
04h
Digital
PCBeep
MUX
Analog
Audio
Sources
MIC1
MIC2
mute 3D
MUX
20h:D8
vol
Digital
SPDIF
1Ch
Record
Volume ADC
38h:D5-D4
Slot
Select
PCMIn
ADCRecord
IDT™
44
STAC9752/9753
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
7.1.
Analog Mixer Input
The mixer provides recording and playback of any audio sources or output mix of all sources. The
STAC9752/9753 supports the following input sources:
•
any mono or stereo source
•
mono or stereo mix of all sources
•
2-channel input w/mono output reference (microphone or stereo mix)
Note: All unused inputs should be tied together and connected to ground through a capacitor (0.1 µ F
suggested).
Note: The MIC should be tied to ground through a separate 0.1 µ F capacitor.
7.2.
Mixer Analog Output
The mixer generates three distinct outputs:
7.3.
•
A stereo mix of all sources for output to the LINE_OUT
•
A stereo mix of all sources for output to HP_OUT
•
A mono, microphone only, or mix of all sources, for MONO_OUT
SPDIF Digital Mux
The STAC9752/9753 incorporates a digital output that supports SPDIF formats. A multiplexer determines which of two digital input streams are used for the digital output conversion process. These
two streams include the PCM_OUT data from the audio controller and the ADC recorded output. The
normal analog LINE_OUT signal can be converted to the SPDIF formats by using the internal ADC
to record the “MIX” output, which is the combination of all analog and all digital sources. In the case
of digital controllers with support for 4 or more channels, the SPDIF output mode can be used to
support compressed 6-channel output streams for delivery to home theater systems. These can be
routed on alternate AC-Link slots to the SPDIF output, while the standard 2-channel output is delivered as selected by bits D5 and D4 in Register 6E. If the digital controller supports 6 channels, a
SPDIF output with 4 analog channels can also be configured.
If the Digital Controller has independent DMA engines, SPDIF and Analog can be used simultaneously and independently.
Pin 48: To Enable SPDIF, use an 1 K Ω to 10 K Ω external pulldown. To Disable SPDIF, use an 1 KΩ
to 10 KΩ external pullup. Do NOT leave Pin 48 floating.
IDT™
45
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
7.4.
PC Beep Implementation
The STAC9752/9753 offers 2 styles of PC BEEP, Analog and Digital. The digital PC Beep is a new
feature added to the AC’97 Specification Rev 2.3. This style of PC Beep will eventually replace the
analog style, thus eliminating the need for a PC Beep pin. Until this feature is widely accepted, IDT
will provide BOTH styles of PC Beep. Both PC Beep styles use Reg 0Ah. Additional information
about Reg 0Ah can be found in Section8.1.5: page51.
7.4.1.
Analog PC Beep
PC Beep is active on power up and defaults to an un-muted state. The PC_BEEP input is routed
directly to the MONO_OUT, LINE_OUT and HP_OUT pins of the CODEC. Because the PC_BEEP
input drive is often a full scale digital signal, some resistive attenuation of the PC_BEEP input is recommended to keep the beep tone within reasonable volume levels. The user should mute this input
before using any other mixer input because the PC Beep input can contribute noise to the lineout
during normal operation. This style of PC Beep is related to the AC’97 Specification Rev 2.2. To use
the analog PC Beep, a value of 00h written to bits F[7:0] (D[12:5]) disables the Digital PC Beep generation. PV[3:0] (D[4:1]) controls the volume level from 0 to 45dB of attenuation in 3dB steps.
7.4.2.
Digital PC Beep
The Digital PC Beep uses the identical register as the analog style, Reg 0Ah. This register controls
the level and frequency for the PC Beep. The beep frequency is the result of dividing the 48 KHz
clock by 4 times the number specified in F[7:0], allowing tones from 47 Hz to 12 KHz. A value of 00h
written to bits F[7:0] disables the digital PC Beep generation and enables the analog PC Beep. The
volume control bits, PV[3:0] operate identically to the analog PC Beep mode. Applying a signal to the
PC Beep pin, pin 12, may cause the digital PC Beep signal to become distorted or inaudible. When
using the digital PC Beep feature, we recommend leaving the PC Beep input pin unconnected or
connected to analog ground through a capacitor. Connecting a capacitor from the PC Beep input pin
to ground will create a more pleasing sound by changing the digital output to a more sinusoidal like
output.
Table 16. Digital PC Beep Examples
Value
1
Reg 0Ah, bits[7:0]
0x01
Frequency
12,000 Hz
10
0x0A
1200 Hz
25
50
0x19
0x32
480 Hz
240 Hz
100
0x64
120 Hz
127
255
0x7F
0xFF
94.48 Hz
47.05 Hz
This will be programmed directly by the BIOS.
IDT™
46
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8. PROGRAMMING REGISTERS
Table 17. Programming Registers
Address
00h
Reset
Default
6A90h
Location
8.1.1; page48
02h
Master Volume
8000h
8.1.2; page48
04h
06h
HP_OUT Mixer Volume
Master Volume MONO
8000h
8000h
8.1.3; page49
8.1.4; page50
0Ah
PC Beep Mixer Volume
0000h
8.1.5; page51
0Ch
0Eh
Phone Mixer Volume
Microphone Mixer Volume
8008h
8008h
8.1.6; page51
8.1.7; page52
10h
Line In Mixer Volume
8808h
8.1.8; page52
12h
14h
CD Mixer Volume
Video Mixer Volume
8808h
8808h
8.1.9; page53
8.1.10; page53
16h
Aux Mixer Volume
8808h
8.1.11; page54
18h
1Ah
PCM Out Mixer Volume
Record Select
8808h
0000h
8.1.12; page54
8.1.13; page55
1Ch
Record Gain
8000h
8.1.14; page55
20h
22h
General Purpose
3D Control
0000h
0000h
8.1.15; page56
8.1.16; page56
24h
Audio Int. & Paging
0000h
8.1.17: page57
26h
28h
Powerdown Ctrl/Stat
Extended Audio ID
000Fh
0A05h
8.1.18; page58
8.1.19; page59
2Ah
Extended Audio Control/Status
0400h*
8.1.20; page61
2Ch
32h
PCM DAC Rate
PCM LR ADC Rate
BB80h
BB80h
8.1.22; page63
8.1.23; page63
3Ah
SPDIF Control
2000h
8.1.24; page64
3Eh
4Ch
Extended Modem Stat/Ctl
GPIO Pin Configuration
0100h
0003h
8.2.4; page65
8.2.5; page66
4Eh
GPIO Pin Polarity/Type
FFFFh
8.2.6; page66
50h
52h
GPIO Pin Sticky
GPIO Wake-up
0000h
0000h
8.2.7; page66
8.2.8; page67
54h
GPIO Pin Status
0000h
8.2.9; page67
60h
CODEC Class/Rev
62h (Page 01h) PCI SVID
1201h
FFFFh
8.3; page68
8.4.2; page70
64h (Page 01h) PCI SSID
FFFFh
8.4.3; page70
66h (Page 01h) Function Select
68h (Page 01h) Function Information
0000h
xxxxh
8.4.4; page71
8.4.5; page72
6Ah
0000h
8.4.6; page73
6Ah (Page01h) Sense Details
6Ch
Revision Code
NA
xxxxh
8.4.7: page74
8.4.7; page74
6Ch (Page01h) Reserved
0000h
NA
6Eh
Analog Special
6Eh (Page01h) Reserved
1000h
0000h
8.4.9: page76
NA
0000h
NA
70h
IDT™
Name
Digital Audio Control
Enable Register
47
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Table 17. Programming Registers (Continued)
Address
Name
Default
Location
72h
Analog Current Adjust
0000h
8.4.10; page77
74h
78h
EAPD Access
High Pass Filter Bypass
0800h
0000h
8.4.11; page77
8.4.12; page78
7Ah
Reserved
NA
NA
7Ch
7Eh
Vendor ID1
Vendor ID2
8384h
7652h
8.5.1; page79
8.5.2; page79
Note: * depends upon CODEC ID
8.1.
Register Descriptions
8.1.1.
Reset (00h)
Default: 6A90h
D15
D14
D13
D12
D11
D10
D9
D8
RSRVD
D7
SE4
D6
SE3
D5
SE2
D4
SE1
D3
SE0
D2
ID9
D1
ID8
D0
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
Writing any value to this register performs a register reset, which causes all registers to revert to
their default values. This register reset also resets all the digital block. Reading this register returns
the ID code of the part.
Bit(s)
15
14:10
9
8
7
6
5
4
3
2
1
0
8.1.2.
Reset Value
0
11010
1
0
1
0
0
1
0
0
0
0
Name
RESERVED
SE4:SE0
ID9
ID8
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
Description
Bit not used, should read back 0
IDT ID for SS3D
20-bit ADC resolution (supported)
18-bit ADC resolution
20-bit DAC resolution (supported)
18-bit DAC resolution
Loudness (bass boost)
Headphone Out (supported)
Simulated Stereo (mono to stereo)
Bass & Treble Control
Reserved
Dedicated MIC PCM IN channel
Master Volume Registers (02h)
Default: 8000h
D15
D14
D13
D12
D11
D10
D9
D8
Mute
RSRVD
ML5
ML4
ML3
ML2
ML1
ML0
D5
MR5
D4
MR4
D3
MR3
D2
MR2
D1
MR1
D0
MR0
D7
D6
RESERVED
IDT™
48
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Bit(s)
Reset Value
Name
15
1
Mute
14
0
RESERVED
13
0
ML5
12:8
0
ML<4:0>
7:6
0
RESERVED
5
0
MR5
4:0
0
MR<4:0>
8.1.3.
Description
0 = No mute
1 = Mutes both left & right channels
Bit not used, should read back 0
0 = Lineout attenuation is a function of bits12-8
1 = Forces register bits 12-8 to be 11111. Always reads back 0.
Left Lineout Volume Control
00000 = 0dB attenuation
00001 = 1.5dB attenuation
.....
11111 = 46.5dB attenuation
Bits not used, should read back 0
0 = Lineout attenuation is a function of bits 4-0
1 = Forces register bits 4-0 to be 11111
Always reads back 0
Right Channel Lineout Volume Control
00000 = 0dB attenuation
00001 = 1.5dB attenuation
.....
11111 = 46.5dB attenuation
Headphone Volume Registers (04h)
Default: 8000h
D15
D14
D13
D12
D11
D10
D9
D8
Mute
D7
RSRVD
D6
HPL5
D5
HPL4
D4
HPL3
D3
HPL2
D2
HPL1
D1
HPL0
D0
HPR5
HPR4
HPR3
HPR2
HPR1
HPR0
RESERVED
IDT™
Bit(s)
Reset Value
Name
15
1
Mute
14
0
RESERVED
13
0
ML5
12:8
0
ML<4:0>
7:6
0
RESERVED
5
0
MR5
4:0
0
MR<4:0>
Description
0 = No mute
1 = Mutes both left & right channels
Bit not used, should read back 0
0 = Headphone attenuation is a function of bits12-8
1 = Forces register bits 12-8 to be 11111. Always reads back 0
Left Headphone Volume Control
00000 = 0dB attenuation
00001 = 1.5dB attenuation
.....
11111 = 46.5dB attenuation
Bits not used, should read back 0
0 = Headphone attenuation is a function of bits 4-0
1 = Forces register bits 4-0 to be 11111. Always reads back 0
Right Channel Headphone Volume Control
00000 = 0dB attenuation
00001 = 1.5dB attenuation
.....
11111 = 46.5dB attenuation
49
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8.1.4.
Master Volume MONO (06h)
Default: 8000h
D15
D14
D13
D12
Mute
D7
D6
RESERVED
IDT™
D11
D10
D9
D8
D2
MM2
D1
MM1
D0
MM0
RESERVED
D5
MM5
Bit(s)
Reset Value
Name
15
1
Mute
14:6
0
RESERVED
5
0
MM5
4:0
0
MM<4:0>
D4
MM4
D3
MM3
Description
0 = No mute
1 = Mute mono
Bit not used, should read back 0
0 = Mono attenuation is a function of bits 4-0
1 = Forces register bits 4-0 to be 11111. Always reads back 0
Mono Volume Control
00000 = 0dB attenuation
00001 = 1.5dB attenuation
.....
11111 = 46.5dB attenuation
50
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8.1.5.
PC BEEP Volume (0Ah)
Default: 0000h
Additional information on the PC Beep can be found in Section 7.4: page46.
D15
Mute
D14
D13
RESERVED
D12
F7
D11
F6
D10
F5
D9
F4
D8
F3
D7
D6
D5
D4
D3
D2
D1
D0
F2
F1
F0
PV3
PV2
PV1
PV0
RSRVD
Bit(s)
Reset Value
Name
15
1
Mute
14:13
0
RESERVED
12:5
00h
F[7:0]
4:1
0
PV(3:0)
0
0
RESERVED
8.1.6.
Description
0 = No mute
1 = Mute PC BEEP
Bit not used, should read back 0
The Beep frequency is the result of dividing the 48 KHz clock by 4 times
the value of the number specified in F[7:0], allowing tones from 47 Hz to
12 KHz.
A value of 00h in bits F[7:0] disables internal PC BEEP generation and
enables external PC BEEP input, if available.
PCBEEP Volume Control
0000 = 0dB attenuation
0001 = 3dB attenuation
.....
1111 = 45dB attenuation
Bit not used, should read back 0
Phone Volume (Index 0Ch)
Default: 8008h.
D15
Mute
D14
D13
D12
D11
RESERVED
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
GN4
GN3
GN2
GN1
GN0
RESERVED
IDT™
Bit(s)
Reset Value
Name
15
1
Mute
14:5
0
RESERVED
4:0
0
GN<4:0>
Description
0 = No mute
1 = Mute phone
Bit not used, should read back 0
Phone Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
51
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8.1.7.
Mic Volume (Index 0Eh)
Default: 8008h.
D15
D14
D13
Mute
D7
D6
RESERVED
BOOSTEN
D12
D11
D5
D4
RESERVED
D3
D2
D1
D0
RESERVED
GN4
GN3
GN2
GN1
GN0
Bit(s)
Reset Value
Name
15
1
Mute
14:7
0
RESERVED
6
0
BOOSTEN
5
0
RESERVED
4:0
8.1.8.
0
GN<4:0>
D10
D9
D8
Description
0 = No mute
1 = Mute phone
Bit not used, should read back 0
Works with MICGAINVAL (Register 6Eh, Bit D2)
BOOSTEN MICGAINVAL = Microphone Gain Boost
0 0 = 0 dB
0 1 = 10 dB
1 0 = 20 dB
1 1 = 30 dB
Phone Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
LineIn Volume (Index 10h)
Default: 8808h.
D15
D14
Mute
D7
IDT™
D13
RESERVED
D6
RESERVED
D5
Bit(s)
Reset Value
Name
15
1
Mute
14:13
0
RESERVED
12:8
0
GL<4:0>
7:5
0
RESERVED
4:0
0
GR<4:0>
D12
D11
D10
D9
D8
GL4
GL3
GL2
GL1
GR0
D4
GR4
D3
GR3
D2
GR2
D1
GR1
D0
GR0
Description
0 = No mute
1 = Mute linein
Bit not used, should read back 0
Left LineIn Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
Bit not used, should read back 0
Right LineIn Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
52
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
8.1.9.
CD Volume (Index 12h)
Default: 8808h.
D15
D14
Mute
D7
D13
D12
D11
D10
D9
D8
RESERVED
D6
D5
GL4
D4
GL3
D3
GL2
D2
GL1
D1
GR0
D0
GR4
GR3
GR2
GR1
GR0
RESERVED
Bit(s)
Reset Value
Name
15
1
Mute
14:13
0
RESERVED
12:8
0
GL<4:0>
7:5
0
RESERVED
4:0
0
GR<4:0>
8.1.10.
Description
0 = No mute
1 = Mute CD
Bit not used, should read back 0
Left CD Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
Bit not used, should read back 0
Right CD Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
Video Volume (Index 14h)
Default: 8808h.
D15
D14
Mute
D7
D13
D12
D11
D10
D9
D8
RESERVED
D6
D5
GL4
D4
GL3
D3
GL2
D2
GL1
D1
GR0
D0
GR4
GR3
GR2
GR1
GR0
RESERVED
IDT™
Bit(s)
Reset Value
Name
15
1
Mute
14:13
0
RESERVED
12:8
0
GL<4:0>
7:5
0
RESERVED
4:0
0
GR<4:0>
Description
0 = No mute
1 = Mute video
Bit not used, should read back 0
Left Video Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
Bit not used, should read back 0
Right video Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
53
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
8.1.11.
Aux Volume (Index 16h)
Default: 8808h.
D15
D14
Mute
D7
D13
D12
D11
D10
D9
D8
RESERVED
D6
D5
GL4
D4
GL3
D3
GL2
D2
GL1
D1
GR0
D0
GR4
GR3
GR2
GR1
GR0
RESERVED
Bit(s)
Reset Value
Name
15
1
Mute
14:13
0
RESERVED
12:8
0
GL<4:0>
7:5
0
RESERVED
4:0
0
GR<4:0>
8.1.12.
Description
0 = No mute
1 = Mute AUX
Bit not used, should read back 0
Left Aux Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
Bit not used, should read back 0
Right Aux Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
PCMOut Volume (Index 18h)
Default: 8808h.
D15
D14
Mute
D7
D13
D12
D11
D10
D9
D8
RESERVED
D6
D5
GL4
D4
GL3
D3
GL2
D2
GL1
D1
GR0
D0
GR4
GR3
GR2
GR1
GR0
RESERVED
IDT™
Bit(s)
Reset Value
Name
15
1
Mute
14:13
0
RESERVED
12:8
0
GL<4:0>
Description
0 = No mute
1 = Mute PCM OUT
Bit not used, should read back 0
Left PCM Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
54
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s)
7:5
Reset Value
0
Name
RESERVED
4:0
0
GR<4:0>
8.1.13.
Description
Bit not used, should read back 0
Right PCM Volume Control
00000 = 12dB gain
00001 = 10.5dB gain
.....
01000 = 0dB gain
.....
11111 = -34.5dB gain
Record Select (1Ah)
Default: 0000h (corresponding to Microphone in)
Used to select the record source independently for right and left.
D15
D14
D7
D6
D13
D12
D11
D4
D3
RESERVED
8.1.14.
D5
RESERVED
Bit(s)
15:11
Reset Value
0
Name
RESERVED
10:8
0
SL2:SL0
7:3
0
RESERVED
2:0
0
SR2:SR0
D10
D9
D8
SL2
SL1
SL0
D2
SR2
D1
SR1
D0
SR0
Description
Bits not used, should read back 0
LEFT CHANNEL INPUT SELECT
000 = Microphone
001 = CD In (left)
010 = Video In (left)
011 = Aux In (left)
100 = Line In (left)
101 = Stereo Mix (left)
110 = Mono Mix
111 = Phone
Bits not used, should read back 0
RIGHT CHANNEL INPUT SELECT
000 = Microphone
001 = CD In (right)
010 = Video In (right)
011 = Aux In (right)
100 = Line In (right)
101 = Stereo Mix (right)
110 = Mono Mix
111 = Phone
Record Gain (1Ch)
Default: 8000h (corresponding to 0 dB gain with mute on)
D15
Mute
D7
D14
D13
D6
RESERVED
D5
D12
D11
D10
D9
D8
D4
GL3
D3
GL2
D2
GL1
D1
GL0
D0
GR3
GR2
GR1
GR0
RESERVED
Bit(s)
15
14:12
IDT™
Reset Value
1
0
Name
MUTE
RESERVED
Description
Mutes RECORD GAIN
Bits not used, should read back 0
55
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s)
Reset Value
Name
11:8
0
GL<3:0>
7:4
0
RESERVED
3:0
0
GR<3:0>
8.1.15.
Description
Left Channel Volume Control
0000 = 0dB gain
0001 = 1.5dB gain
....
1111 = 22.5dB gain
Bits not used, should read back 0
Right Channel Volume Control
0000 = 0dB gain
0001 = 1.5dB gain
....
1111 = 22.5dB gain
General Purpose (20h)
Default: 0000h
D15
D14
D13
D12
D11
D10
D9
D8
POP BYP
D7
RESERVED
D6
3D
D5
D4
RESERVED
D3
D2
MIX
D1
MS
D0
LOOPBACK
8.1.16.
RESERVED
Bit(s)
Reset
Value
Name
15
0
POP BYPASS
14
0
RESERVED
13
0
3D
12:10
9
8
0
0
0
RESERVED
MIX
MS
7
0
LOOPBACK
6:0
0
RESERVED
Description
0 = Normal
1 = DAC bypasses mixer and connects directly to Line Out, Headphone
Out and Mono Out.
Bit not used, should read back 0
0 = 3D EFFECT disabled
1 = 3D EFFECT enabled
Bits not used, should read back 0
Mono Output select (0 = Mix, 1 = Microphone)
Microphone select (0 = Microphone1, 1 = Microphone2)
1 = Enables ADC to DAC Loopback Test
0 = Loopback Disabled
Do not send in conflicting data on AC-Link while running this.
Bits not used, should read back 0
3D Control (22h)
Default: 0000h
D15
D14
D13
D12
D11
D10
D9
D8
D2
DP2
D1
D0
RESERVED
RESERVED
D7
IDT™
D6
D5
RESERVED
D4
56
D3
DP3
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s)
15:4
Reset Value
0
Name
RESERVED
3:2
0
DP3, DP2
1:0
0
RESERVED
Description
Bits not used, should read back 0
LINE_OUT SEPARATION RATIO
DP3 DP2 effect
0 0
0 ( OFF )
0 1
3 ( LOW )
1 0
4.5 ( MED )
1 1
6 ( HIGH )
Bits not used, should read back 0
This register is used to control the 3D stereo enhancement function, IDT Surround 3D (SS3D), built
into the AC'97 component. Note that register bits DP3-DP2 are used to control the separation ratios
in the 3D control for LINE_OUT. SS3D provides for a wider soundstage extending beyond the normal 2-speaker arrangement. Note that the 3D bit in the general purpose register (20h) must be set to
1 to enable SS3D functionality to allow the bits in 22h to take effect. The three separation ratios are
implemented. The separation ratio defines a series of equations that determine the amount of depth
difference (High, Medium, and Low) perceived during 2-channel playback. The ratios provide for
options to narrow or widen the soundstage.
8.1.17.
Audio Interrupt and Paging (24h)
Default: 0000h
D15
D14
D13
I4
I3
I2
I1
I0
D7
D6
D5
RESERVED
D4
D3
PG3
Bit(s) Reset Value
IDT™
D12
Access
Name
15
0
Read / Write
I4
14-13
0
Read Only
I3-I2
12
0
Read / Write
I1
D11
D10
D9
D8
RESERVED
D2
PG2
D1
PG1
D0
PG0
Description
0 = Interrupt is clear
1 = Interrupt is set
Interrupt event is cleared by writing a 1 to this bit.
The interrupt bit will change regardless of condition of interrupt
enable (I0) status. An interrupt in the GPI in slot 12 in the ACLink
will follow this bit change when interrupt enable (I0) is unmasked.
Interrupt Cause
00 = Reserved
01 = Sense Cycle Complete, sense info available.
10 = Change in GPIO input status
11 = Sense Cycle Complete and Change in GPIO input status.
These bits will reflect the general cause of the first interrupt event
generated. It should be read after interrupt status has been
confirmed as interrupting. The information should be used to scan
possible interrupting events in proper pages.
Sense Cycle
0 = Sense Cycle not in Progress
1 = Sense Cycle Start.
Writing a 1 to this bit causes a sense cycle start if supported. If
sense cycle is not supported this bit is read only.
57
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s) Reset Value
11
0
10:4
0
3:0
0
8.1.18.
Access
Name
Description
Interrupt Enable
0 = Interrupt generation is masked.
1 = Interrupt generation is un-masked.
The driver should not un-mask the interrupt unless ensured by the
AC ‘97 controller that no conflict is possible with modem slot 12 Read / Write
I0
GPI functionality. Some AC’97 2.2 compliant controllers will not
likely support audio CODEC interrupt infrastructure. In either case,
S/W should poll the interrupt status after initiating a sense cycle
and wait for Sense Cycle Max Delay to determine if an interrupting
event has occurred.
Read Only RESERVED Bits not used, should read back 0
Page Selector
0h = Vendor Specific
1h = Page ID 01 (See Section 8.4 for additional information on the
Paging Registers)
Fh = Reserved Pages
This register is used to select a descriptor of 16 word pages
between registers 60h to 6Fh. Value 0h is used to select vendor
Read / Write PG3:PG0
specific space to maintain compatibility with AC’97 2.2 vendor
specific registers.
System S/W determines implemented pages by writing the page
number and reading the value back. All implemented pages must
be consecutive. (i.e., page 2h cannot be implemented without page
1h).
These registers are NOT reset on RESET#.
Powerdown Ctrl/Stat (26h)
Default: 000Fh
IDT™
D15
D14
D13
D12
D11
D10
D9
D8
EAPD
PR6
PR5
PR4
PR3
PR2
PR1
PR0
D7
D6
D4
D3
REF
D2
ANL
D1
DAC
D0
ADC
D5
RESERVED
Bit(s)
Reset Value
Name
15
0
EAPD
14
0
PR6
13
0
PR5
12
0
PR4
11
0
PR3
10
0
PR2
9
0
PR1
Description
1 = Forces EAPD pad to Vdd
0 = Forces EAPD pad to GND
0 = Headphone Amp powered up
1 = Headphone Amp powered down
0 = Digital Clk active
1 = Digital Clk disable.
0 = digital active
1 = Powerdown: PLL, AC-Link, Xtal oscillator ;
0 = VREF and VREFOUT are active
1 = VREF and VREFOUT are powered down, and PR2 is asserted in
analog block
0 = analog active
1 = all signal path analog is powered down
0 = DAC powered up
1 = DAC powered down
58
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s)
Reset Value
Name
8
0
PR0
7:4
0
RESERVED
3
1
REF
2
1
ANL
1
1
DAC
0
1
ADC
8.1.18.1.
Description
0 = ADC powered up
1 = ADC powered down
Bit not used, should read back 0
Read Only --- VREF status
1 = VREFs enabled
Read Only ---- ANALOG MIXERS, etc. Status
1 = Analog Mixers ready.
Read Only ---- DAC Status
1 = DAC ready to playback
Read Only ---- ADC Status
1 = ADC ready to record
Ready Status
The lower half of this register is read only status, a 1 indicating that each subsection is “ready”.
Ready is defined as the subsection's ability to perform in its nominal state. When this register is written, the bit values that come in on AC-Link will have no effect on read-only bits 0-7.
When the AC-Link “CODEC Ready” indicator bit (SDATA_IN slot 0, bit 15) is a 1, it indicates that the
AC-Link and AC'97 control and status registers are in a fully operational state. The AC'97 controller
must further probe this Powerdown Control/Status Register to determine exactly which subsections,
if any, are ready. When this register is written, the bit values that come in on AC-Link will have no
effect on read-only bits 0-7.
8.1.18.2.
Powerdown Controls
The STAC9752/9753 is capable of operating at reduced power when no activity is required. The
state of power down is controlled by the Powerdown Register (26h). See the section “Low Power
Modes” for more information.
8.1.18.3.
External Amplifier Power Down Control Output
The EAPD bit 15 of the Powerdown Control/Status Register (Index 26h) directly controls the output
of the EAPD output, pin 45, and produces a logical 1 when this bit is set to logic high. This function is
used to control an external audio amplifier power down. EAPD = 0 places approximately 0V on the
output pin, enabling an external audio amplifier. EAPD = 1 places approximately DVdd on the output
pin, disabling the external audio amplifier. Audio amplifiers that operate with reverse polarity will
likely require an external inverter to maintain software driver compatibility.
EAPD can also act as a GPIO. See Section 8.4.11: page77. The GPIO controls in Section 8.2:
page64 have no effect on EAPD.
8.1.19.
Extended Audio ID (28h)
Default: 0A05h
D15
ID1
D14
ID0
D7
D6
RESERVED
IDT™
D13
D12
D11
RESERVED
D10
D9
AMAP
D8
RSVD
D5
D4
D3
D2
D1
D0
DSA1
DSA0
RSVD
SPDIF
RSVD
VRA
59
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
The Extended Audio ID register is a read only register except for bits D4 and D5. ID1 and ID0 echo
the configuration of the CODEC as defined by the programming of pins 45 and 46 externally. The
primary CODEC returns “00”, while any other code identifies the CODEC as one of three secondary
CODEC possibilities. The AMAP bit, D9, will return a 1 indicating that the CODEC supports the
optional “AC’97 2.3 compliant AC-Link slot to audio DAC mappings”.The default condition assumes
that 0 is loaded into the DSA0 and DSA1 bits of the Extended Audio ID (Index 28h). With 0 in the
DSA1 and DSA0 bits, the CODEC slot assignments are as per the AC’97 specification recommendations. If the DSA1 and DSA0 bits do not contain 0, the slot assignments are as per the table in the
section describing the Extended Audio ID (Index 28h). The VRA bit, D0, will return a 1 indicating that
the CODEC supports the optional variable sample rate conversion as defined by the AC’97 specification.
Table 18. Extended Audio ID Register Functions
Bit
Access
Reset Value
variable
Function
0,0 = XTAL_OUT grounded (Note 1)
CID1#, CID0# = XTAL_OUT crystal or floating
15:14
ID [1,0]
Read only
13:12
RESERVED
Read only
00
Bits not used, should read back 00
11:10
9:6
REV[1:0]
RSVD
Read only
Read only
10
0
Indicates CODEC is AC’97 Rev 2.3 compliant
Reserved
00
DAC slot assignment
5:4
1.
2.
DSA [1,0]
Read/Write
If CID[1:0] = 00 then DSA[1:0] resets to 00
If CID[1:0] = 01 then DSA[1:0] resets to 01
If CID[1:0] = 10 then DSA[1:0] resets to 01
If CID[1:0] = 11 then DSA[1:0] resets to 10
00 = left slot 3, right slot 4
01 = left slot 7, right slot 8
10 = left slot 6, right slot 9
11 = left slot 10, right slot 11
RESERVED
3
RSVD
Read only
0
2
SPDIF
Read only
1
1
RSVD
Read only
0
0
IDT™
Name
0 = SPDIF pulled high on reset, SPDIF disabled
1 = default, SPDIF enabled (Note 2)
RESERVED
VRA
Read only
1
Variable sample rates supported (Always = 1)
External CID pin status (from analog) these bits are the logical inversion of the pin polarity (pin 45-46).
These bits are zero if XTAL_OUT is grounded with an alternate external clock source in primary mode
only. Secondary mode can either be through BIT CLK driven or 24MHz clock driver, with XTAL_OUT
floating.
If pin 48 is held high at powerup, this bit will be held to zero, to indicate the SPDIF is not available.
Pin 48: To Enable SPDIF, use an external 1KΩ - 1 0 KΩ pulldown resistor. To Disable SPDIF, use an
external 1KΩ - 1 0 KΩ pullup resistor. Do NOT leave Pin 48 floating.
60
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
8.1.20.
Extended Audio Control/Status (2Ah)
Default: 0400h* (*default depends on CODEC ID)
D15
D14
D13
VCFG
D12
D11
RESERVED
D7
D6
RESERVED
D5
SPSA1
D4
SPSA0
D10
D9
SPCV
D3
RSRVD
D2
SPDIF
D8
RESERVED
D1
RSRVD
D0
VRA enable
Note: If pin 48 is held high at powerup, the SPDIF is not available and bits D15:D1 can not be written and will
read back zero.
Pin 48: To Enable SPDIF, use an external 1KΩ - 1 0 KΩ pulldown resistor. To Disable SPDIF, use an
external 1KΩ - 1 0 KΩ pullup resistor. Do NOT leave Pin 48 floating.
Bit(s) Reset Value
15
VCFG
14-11
Reserved
10
0
SPCV
9:6
0
Reserved
5:4
0
3
2
IDT™
Name
If CID[1:0] = 00 then SPSA[1:0] resets to 01
If CID[1:0] = 01 then SPSA[1:0] resets to 10
If CID[1:0] = 10 then SPSA[1:0] resets to 10
SPSA1:SPSA0 If CID[1:0] = 11 then SPSA[1:0] resets to 11
Reserved
0
Description
Determines the SPDIF transmitter behavior when data is not being
transmitted. When asserted, this bit forces the deassertion of the SPDIF
“Validity” flag, which is bit 28 transmitted by the SPDIF sub-frame. The “V” bit
is defined in the SPDIF Control Register (Reg 3Ah).
If “V” = 1 and “VCFG” = 0, then for each S/PDIF sub-frame (Left & Right),
bit[28] “Validity” flag reflects whether or not an internal CODEC transmission
error has occurred. Specifically an internal CODEC error should result in the
“Validity” flag being set to 1.
If “V” = 0 and “VCFG” = 1, In the case where the S/PDIF transmitter does not
receive a valid sample from the AC'97 controller, (Left or Right), the S/PDIF
transmitter should set the “Validity” flag to “0” and pad the “Audio Sample
Word” with “0”s for sub-frame in question. If a valid sample (Left or Right) was
received and successfully transmitted, the “Validity” flag should be “0” for that
sub-frame.
Default state, coming out of reset, for “V” and “VCFG” should be 0 and 0.
These bits can be set via driver .inf options.
Reserved
0 = Invalid SPDIF configuration
1 = Valid SPDIF configuration
Bit not used, should read back 0
SPDIF slot assignment
SPDIF
00 = left slot 3, right slot 4
01 = left slot 7, right slot 8
10 = left slot 6, right slot 9
11 = left slot 10, right slot 11
Reserved
0 = Disables SPDIF (SPDIF_OUT is high Z) (note 1)
1 = Enable SPDIF
SPDIF is a control register for Reg 3Ah, this bit must be set low i.e. SPDIF
disabled in order to write to Reg 3Ah Bits D15,D13:D0.
61
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s) Reset Value
1
0
0
0
8.1.20.1.
Name
Reserved
VRA Enable
Description
Bit not used, should read back 0
0 = VRA Disabled, DAC and ADC set to 48 KHz (Registers 2Ch and 32h
loaded with the value BB80h)
1 = VRA Enabled, Reg. 2Ch & 32h control sample rate
Variable Rate Sampling Enable
The Extended Audio Status Control register also contains one active bit to enable or disable the
Variable Sampling Rate capabilities of the DACs and ADCs. If the VRA (bit D0) is 1, the variable
sample rate control registers (2Ch and 32h) are active, and “on-demand” slot data required transfers
are allowed. If the VRA bit is 0, the DACs and ADCs will operate at the default 48 KHz data rate.
The STAC9752/9753 supports “on-demand” slot request flags. These flags are passed from the
CODEC to the AC’97 controller in every audio input frame. Each time a slot request flag is set (active
low) in a given audio frame, the controller will pass the next PCM sample for the corresponding slot
in the audio frame that immediately follows. The VRA enable bit must be set to 1 to enable
“on-demand” data transfers. If the VRA enable bit is not set, the CODEC defaults to 48 KHz transfers
and every audio frame includes an active slot request flag and data transfers every frame.
For variable sample rate output, the CODEC examines its sample rate control registers, the state of
the FIFOs, and the incoming SDATA_OUT tag bits at the beginning of each audio output frame to
determine which SLOTREQ bits to set active (low). SLOTREQ bits are asserted during the current
audio input frame for active output slots, which will require data in the next audio output frame.
For variable sample rate input, the tag bit for each input slot indicates whether valid data is present
or not. Thus, even in variable sample rate mode, the CODEC is always the master: for SDATA_IN
(CODEC to Controller), the CODEC sets the TAG bit; for SDATA_OUT (Controller to CODEC), the
CODEC sets the SLOTREQ bit and then checks for the TAG bit in the next frame. Whenever VRA is
set to 0, the PCM rate registers (2Ch and 32h) are overwritten with BB80h (48 KHz).
8.1.20.2.
SPDIF
The SPDIF bit in the Extended Audio Status Control Register is used to enable and disable the
SPDIF functionality within the STAC9752/9753. If the SPDIF is set to a 1, then the function is
enabled, and when set to a 0 it is disabled.
8.1.20.3.
SPCV (SPDIF Configuration Valid)
The SPCV bit is read only and indicates whether or not the SPDIF system is set up correctly. When
SPCV is a 0, it indicates the SPDIF configuration is invalid. When SPCV is a 1, it indicates the
SPDIF configuration is valid.
8.1.20.4.
SPSA1, SPSA0 (SPDIF Slot Assignment)
SPSA1 and SPSA0 combine to provide the slot assignments for the SPDIF data. The following
details the slot assignment relationship between SPSA1 and SPSA0.
The STAC9752/9753 are AMAP compliant with the following table.
IDT™
62
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Table 19. AMAP compliant
CODEC
ID
8.1.21.
SPSA = 00
SPSA = 01
SPSA = 10
SPSA = 11
slot assignment slot assignment slot assignment slot assignment
Function
00
2-ch Primary w/SPDIF
3&4
7 & 8*
6&9
10 & 11
01
10
2-ch Dock CODEC w/SPDIF
+2-ch Surr w/ SPDIF
3&4
3&4
7&8
7&8
6 & 9*
6 & 9*
10 & 11
10 & 11
11
+2-ch Cntr/LFE w/ SPDIF
3&4
7&8
Note: * indicates the default slot assignment
6&9
10 & 11*
PCM DAC Rate Registers (2Ch and 32h)
The internal sample rate for the DACs and ADCs are controlled by a value in these read/write registers (that contain a 16-bit unsigned value between 0 and 65535) representing the conversion rate in
Hertz (Hz). In VRA mode (register 2Ah bit D0 = 1), if the value written to these registers is supported,
that value will be echoed back when read; otherwise the closest (higher in the case of a tie) sample
rate is supported and returned. Per PC 99 / PC 2001 specification, independent sample rates are
supported for record and playback.
Whenever VRA is set to 0 the PCM rate registers (2Ch and 32h) will be loaded with BB80h (48 KHz).
If VRA is set to a 0, any write to this address will be ignored and the rate remains at 48 KHz.
Table 20. Hardware Supported Sample Rates
Sample Rate
8.1.22.
SR[15:0] Value
8 KHz
11.025 KHz
1F40h
2B11h
16 KHz
3E80h
22.05 KHz
32 KHz
5622h
7D00h
44.1 KHz
AC44h
48 KHz
BB80h
PCM DAC Rate (2Ch)
Default: BB80h (see table20: page63)
8.1.23.
D15
D14
D13
D12
D11
D10
D9
D8
SR15
SR14
SR13
SR12
SR11
SR10
SR9
SR8
D7
SR7
D6
SR6
D5
SR5
D4
SR4
D3
SR3
D2
SR2
D1
SR1
D0
SR0
PCM LR ADC Rate (32h)
Default: BB80h (see table20: page63)
IDT™
D15
D14
D13
D12
D11
D10
D9
D8
SR15
D7
SR14
D6
SR13
D5
SR12
D4
SR11
D3
SR10
D2
SR9
D1
SR8
D0
SR7
SR6
SR5
SR4
SR3
SR2
SR1
SR0
63
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
8.1.24.
SPDIF Control (3Ah)
Default: 2000h
D15
D14
D13
D12
D11
D10
D9
D8
V
DRS
SPSR1
SPSR2
L
CC6
CC5
CC4
D7
CC3
D6
CC2
D5
CC1
D4
CC0
D3
PRE
D2
COPY
D1
/AUDIO
D0
PRO
Bit(s)
Reset Value
Access
Name
15 in 2.3
8.2.
Description (note 1-2)
Validity: This bit affects the “Validity” flag, bit[28] transmitted in
each S/PDIF subframe, and enables the S/PDIF transmitter to
maintain connection during error or mute conditions. Subframe
bit[28] = 0 indicates that data is valid for conversion at the
receiver, 1 indicates invalid data (not suitable for conversion at
the receiver).
V
14
0
13:12
10
11
0
10:4
0
3
0
2
0
1
0
0
0
If “V” = 1, then each S/PDIF subframe (Left & Right) should have
bit[28] “Validity” flag = 1 or set based on the assertion or
de-assertion of the AC'97 “VFORCE” bit within the Extended
Audio Status and Control Register (D15, register 2Ah).
Read Only
DRS
1 = Double Rate SPDIF support (always = 0)
SPDIF Sample Rate.
00 - 44.1 KHz Rate
Read & Write SPSR[1,0] 01 - Reserved
10 - 48 KHz Rate (default)
11 - 32 KHz Rate
Generation Level is defined by the IEC standard, or as
Read & Write
L
appropriate.
Category Code is defined by the IEC standard or as appropriate
Read & Write CC[6, 0]
by media.
0 = Pre-emphasis = 0 µsec
Read & Write
PRE
1 = Pre-emphasis = 50/15 µsec
0 = Copyright not asserted
Read & Write
COPY
1 = Copyright is asserted
0 = PCM data
Read & Write /AUDIO
1 = Non-Audio or non-PCM format
0 = Consumer use of the channel
Read & Write
PRO
1 = Professional use of the channel
General Purpose Input & Outputs
8.2.1.
EAPD
EAPD can act as a GPIO, but is unaffected by the following registers. To use EAPD as a GPIO, use
Register 74h, the EAPD Access Register located in Section 8.4.11: page77. Additional information
about EAPD can also be found in Section 8.1.18.3: page 59.
IDT™
64
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REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
8.2.2.
GPIO Pin Definitions
GPIO pins are programmable to have input/output functionality. The data values (status) for these
pins are all in one register with input/output configuration in a separate register. Control of GPIO pins
configured for output is achieved by setting the corresponding bit in output slot 12; status of GPIO
pins configured for input is returned on input slot 12. The CODEC must constantly set the GPIO pins
that are configured for output, based upon the value of the corresponding bit position of the control
slot 12. The CODEC should ignore output slot 12 bits that correspond to GPIO control pins configured as inputs. The CODEC must constantly update status on input slot 12, based upon the logic
level detected at each GPIO pin configured for input. A GPIO output pin value that is written via
slot 12 in the current frame will not affect the GPIO status that is returned in that particular write
frame.
This slot-12 based control/status protocol minimizes the latency and complexity, especially for
host-based Controllers and host data pump software, and provides high speed monitoring and control, above what could be achieved with command/status slots. For host-based implementations,
most AC‘97 registers can be shadowed by the driver in order to provide immediate response when
read by the processor, and GPIO pins configured as inputs should be capable of triggering an interrupt upon a change of status.
The AC-Link request for GPIO pin status is always delayed by at least one frame time. Read-Modify-Write operations across the AC-Link will incur latency that must be accounted for by the software
driver or AC‘97 Digital Controller firmware. PCI retries should be kept to a minimum wherever possible.
8.2.3.
GPIO Pin Implementation
The GPIOs are set to a high impedance state on power-on or a cold reset. It is up to the AC‘97 Digital Controller to first enable the output after setting it to the desired state.
8.2.4.
Extended Modem Status and Control Register (3Eh)
Default: 0100h
D15
D14
D13
D7
D6
D5
D12
RESERVED
D11
D10
D9
D4
D3
D2
D1
RESERVED
IDT™
Bit(s)
15:9
Access
Read Only
Reset Value
0
Name
RESERVED
8
Read / Write
1
PRA
7:1
Read Only
0
RESERVED
0
Read Only
0
GPIO
65
D8
PRA
D0
GPIO
Description
Bit not used, should read back 0
0 = GPIO powered up / enabled
1 = GPIO powered down / disabled
Bit not used, should read back 0
0 = GPIO not ready (powered down)
1 = GPIO ready (powered up)
STAC9752/9753
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8.2.5.
GPIO Pin Configuration Register (4Ch)
Default: 0003h
D15
D14
D13
D12
D11
RESERVED
D7
D6
D5
D4
D3
D10
D9
D8
D2
D1
D0
GC1
(GPIO1)
GC0
(GPIO0)
RESERVED
Bit(s)
15:2
Access
Read Only
Reset Value
0
Name
RESERVED
1
Read / Write
1
GC1
0
Read / Write
1
GC0
8.2.6.
Description
Bit not used, should read back 0
0 = GPIO1 configured as output
1 = GPIO1 configured as input
0 = GPIO0 configured as output
1 = GPIO0 configured as input
GPIO Pin Polarity/Type Register (4Eh)
Default: FFFFh
D15
D14
D13
D12
D11
RESERVED
D7
D6
D5
D4
D3
D10
D2
RESERVED
Bit(s)
15:2
Access
Read Only
Reset Value
0
Name
RESERVED
1
Read / Write
1
GP1
0
Read / Write
1
GP0
8.2.7.
D9
D8
D1
D0
GP1
(GPIO1)
GP0
(GPIO0)
Description
Bit not used, should read back 0
0 = GPIO1 Input Polarity Inverted, CMOS output drive.
1 = GPIO1 Input Polarity Non-inverted, Open-Drain output
drive.
0 = GPIO0 Input Polarity Inverted, CMOS output drive.
1 = GPIO0 Input Polarity Non-inverted, Open-Drain output
drive.
GPIO Pin Sticky Register (50h)
Default: 0000h
D15
D14
D13
D12
D11
RESERVED
D7
D6
D5
D4
D3
D10
D9
D8
D2
D1
D0
GS1
(GPIO1)
GS0
(GPIO0)
RESERVED
IDT™
Bit(s)
15:2
Access
Read Only
Reset Value
0
Name
RESERVED
1
Read / Write
0
GS1
0
Read / Write
0
GS0
66
Description
Bit not used, should read back 0
0 = GPIO1 Non Sticky configuration.
1 = GPIO1 Sticky configuration.
0 = GPIO0 Non Sticky configuration.
1 = GPIO0 Sticky configuration.
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8.2.8.
GPIO Pin Mask Register (52h)
Default: 0000h
D15
D14
D13
D12
D11
D10
D9
D8
D2
D1
GW1
(GPIO1)
D0
GW0
(GPIO0)
RESERVED
D7
D6
D5
D4
D3
RESERVED
Bit(s)
15:2
Access
Read Only
Reset Value
0
Name
RESERVED
1
Read / Write
0
GW1
0
Read / Write
0
GW0
8.2.9.
Description
Bit not used, should read back 0
0 = GPIO1 interrupt not passed to GPIO_INT slot 12.
1 = GPIO1 interrupt is passed to GPIO_INT slot 12.
0 = GPIO0 interrupt not passed to GPIO_INT slot 12.
1 = GPIO0 interrupt is passed to GPIO_INT slot 12.
GPIO Pin Status Register (54h)
Default: 0000h
D15
D7
D14
D6
D13
D12
D11
D10
D5
RESERVED
D4
D3
D2
RESERVED
Bit(s)
15:2
1
0
IDT™
D9
D8
D1
D0
GI1 (GPIO1)
GI0 (GPIO0)
Access
Read Only
Reset Value
Name
Description
0
RESERVED Bits not used, should read back 0
When GPIO1 is configured as output and Register h74 bit[0] = 0
(default), the value of this register will be placed on the GPIO1
pad.
When GPIO1 is configured as output and Register h74 bit[0] =1,
the GPIO1 pad will get its value from slot12.
Read / Write
x
GI1
When GPIO1 is configured as input and configured as a sticky bit,
writing a 1 does nothing, writing a 0 clears this bit.
When GPIO1 is configured as input, this register reflects the value
on the GPIO1 pad after interpretation of the polarity and sticky
configurations.
When GPIO0 is configured as output and Register h74 bit[0] = 0
(default), the value of this register will be placed on the GPIO0
pad.
When GPIO0 is configured as output and Register h74 bit[0] =1,
the GPIO0 pad will get its value from slot12.
Read / Write
x
GI0
When GPIO0 is configured as input and configured as a sticky bit,
writing a 1 does nothing, writing a 0 clears this bit.
When GPIO0 is configured as input, this register reflects the value
on the GPIO0 pad after interpretation of the polarity and sticky
configurations.
67
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8.3.
Extended CODEC Registers Page Structure Definition
Registers 60h-68h are the Extended CODEC Registers: These registers allow for the definition of further capabilities. These bits provide a paged address space for extended
CODEC information. The Page Selector bits in the Audio Interrupt and Paging register
(Register 24h bits 3:0) control the page of information viewed through this page window.
8.3.1.
Extended Registers Page 00
Page 00 of the Extended CODEC Registers is reserved for vendor specific use. Driver writers should not access these registers unless the Vendor ID register has been checked first
to ensure that the vendor of the AC'97 component has been identified and the usage of the
vendor defined registers understood.
8.3.2.
Extended Registers Page 01
The usage of Page 01 of the Extended CODEC Registers is defined in Register 24h found
in Section 8.1.17: page 57.
8.3.3.
Extended Registers Page 02, 03
Pages 02 and 03 of the Extended CODEC Registers are reserved for future use.
IDT™
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8.4.
STAC9752/9753 Paging Registers
The AC’97 Specification Rev 2.3 uses a paging mechanism in order to increase the number of registers. The registers currently used in the paging are 60h to 6Eh. For additional information about the
Extended CODEC Registers, please refer to Section 8.3: page68.
One of two pages can be made active at any time, set in Register 24h. Register 24h is the Audio
Interrupt and Paging Register. Additional details about Register 24h is located in Section 8.1.17:
page57.
If page 00h is active, registers 60h to 6Eh are Vendor Specific.
If page 01h is active, registers 60h to 6Eh have the following functionality:
Reg
FUNCTION
Provides the CODEC Class and a Vendor specified revision
60h CODEC Class/Revision
identifier.
Allows for population by the system BIOS to identify the PCI
62h PCI SVID
Sub System Vendor ID.
Allows for population by the system BIOS to identify the PCI
64h PCI SSID
Sub System ID.
Provides the type of audio function being selected and which
66h Function Select
jack conductor the selected value is measured from.
Includes information about Gain, Inversion, Buffer delays,
68h Function Information
Information Validity, and Function Information presence.
Includes information about the connector/jack location, Input
6Ah Sense Register
verses Output sensing, the order of the sense results, and
the IDT specific sense results.
6Ch
Reserved
6Eh
Reserved
8.4.1.
NAME
Location
8.4.1: page69
8.4.2: page70
Note:: page70
Note:: page70
8.4.5: page72
8.4.7: page74
CODEC Class/Rev (60h Page 01h )
Register 24h must be set to Page 01h to access this register.
Default: 12xxh
D15
D7
RV7
D14
RESERVED
D6
RV6
D13
D5
RV5
D12
CL4
D4
RV4
Bit(s) Reset Value Name
15-13
Reserved Reserved-not defined
IDT™
69
D11
CL3
D3
RV3
D10
CL2
D2
RV2
D9
CL1
D1
RV1
D8
CL0
D0
RV0
Description
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Bit(s) Reset Value
12-8
7-0
8.4.2.
Name
Description
CODEC Compatibility Class (RO)
This is a CODEC vendor specific field to define software compatibility for the
CODEC. Software reads this field together with the CODEC vendor ID (reg 7C-7Eh)
to determine vendor specific programming interface compatibility. Software can rely
CL4:CL0 on vendor specific register behavior to be compatible among vendor CODECs of
the same class.
00h - Field not implemented
01h-1Fh - Vendor specific compatibility class code
Equals Vendor ID2 (Reg 7Eh) bits D7 to D0
Revision ID: (RO)
This register specifies a device specific revision identifier. The value is chosen by
the vendor. Zero is an acceptable value. This field should be viewed as a vendor
RV7:RV0
defined extension to the CODEC ID. This number changes with new CODEC
stepping of the same CODEC ID.
Equals Major Rev bits (Reg 6Ch) bits D7 to D0.
PCI SVID (62h Page 01h)
Register 24h must be set to Page 01h to access this register.
Default: FFFFh
D15
D14
D13
D12
D11
D10
D9
D8
PVI15
PVI14
PVI13
PVI12
PVI11
PVI10
PVI9
PVI8
D7
PVI7
D6
PVI6
D5
PVI5
D4
PVI4
D3
PVI3
D2
PVI2
D1
PVI1
D0
PVI0
Bit(s) Reset Value
15-0
Name
Description
PCI Sub System Vendor ID:
This field provides the PCI Sub System Vendor ID of the Audio or Modem Sub
PVI15:PVI0 Assembly Vendor (i.e., CNR Manufacturer, Motherboard Vendor). This is NOT the
CODEC vendor PCI Vendor ID, nor the AC'97 Controller PCI Vendor ID.
If data is not available, returns FFFFh.
Note: This register is populated by the BIOS and does not reset on RESET#.
8.4.3.
PCI SSID (64h Page 01h)
Register 24h must be set to Page 01h to access this register.
Default: FFFFh
D15
D14
D13
D12
D11
D10
D9
D8
PI15
PI14
PI13
PI12
PI11
PI10
PI9
PI8
D7
PI7
D6
PI6
D5
PI5
D4
PI4
D3
PI3
D2
PI2
D1
PI1
D0
PI0
Bit(s) Reset Value
15-0
Name
Description
PCI Sub System ID:
This field provides the PCI Sub System ID of the Audio or Modem Sub Assembly
(i.e., CNR Model, Motherboard SKU). This is NOT the CODEC vendor PCI ID, nor
PI15:PVI0
the AC'97 Controller PCI ID. Information in this field must be available for AC'97
controller reads when CODEC Ready is asserted in AC-Link. If data is not
available, returns FFFFh.
Note: This register is populated by the BIOS and does not reset on RESET#.
IDT™
70
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8.4.4.
Function Select (66h Page 01h )
Register 24h must be set to Page 01h to access this register.
Default: 0000h
D15
D14
D13
D12
D11
D10
D9
D8
D2
FC1
D1
FC0
D0
T/R
RESERVED
D7
D6
RESERVED
D5
D4
FC3
D3
FC2
Bit(s) Reset Value
Name
Description
15-5
Reserved Reserved
Function Code bits:
00h - Line Out (Master Out)
01h - Head Phone Out (AUX Out)
Setting the T/R bit to 0 = Left,1 = Right
02h - DAC 3 (C/LFE) - Not Supported
03h - SPDIF out
04h - Phone In
05h - Mic1 (Microphone select = 0)
06h - Mic2 (Microphone select = 1)
07h - Line In
08h - CD In
09h - Video In
4-1
00h
FC3:FC0 0Ah - Aux In
0Bh - Mono Out
0C-0Fh - Reserved
For supported Jack and Microphone Sense Functions, see Table21: page71.
The Function Code Bits are used to read Register 68h (Page 01h) and Register
6Ah (Page 01h).
Mono I/O should report relevant sense and function information on Tip, and report
Not-Supported on Ring.
0
0
T/R
Setting the function code to unsupported values will return a 0 when accessing the
Information Valid Bit in Page 01, Register 68h, bit 5.
Tip or Ring Selection Bit.This bit sets which jack conductor the sense value is
measured from. Software will program the corresponding the Ring/Tip selector bit
together with the I/O number in bits FC[3:0].
0 - Tip (Left)
1 - Ring (Right)
Note: This register does not reset on RESET#.
Table 21. Supported Jack and Microphone Sense Functions
IDT™
Function Code
I/O
Sense Capability
00h
Line_Out
Jack Sense
01h
05h
Headphone_Out
Mic1
Jack Sense
Microphone Sense
06h
Mic2
Microphone Sense
71
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
8.4.5.
Function Information (68h Page 01h)
Register 24h must be set to Page 01h to access this register.
Default: 00xxh, see table 22: page73.
D15
G4
D14
G3
D12
G1
D11
G0
D3
D7
D6
D5
D4
DL2
DL1
DL0
IV
Bit(s) Reset Value
IDT™
D13
G2
Name
15
0
G4
14-11
0
G3:G0
10
INV
9-5
DL4:DL0
D10
INV
D9
DL4
D2
D1
RESERVED
D8
DL3
D0
FIP
Description
Gain Sign Bit: The CODEC updates this bit with the sign of the gain value
present in G[3:0]. The BIOS updates this to take into consideration external
amplifiers or other external logic when relevant.
G[4] indicates whether the value is a gain or attenuation.
Gain in the G4 bit is in terms of dB.
This bit is Read/Write and is only reset on POR and not by RESET#.
Gain Bits: The CODEC updates these bits with the gain value (db relative to
level-out) in 1.5dBV increments. The BIOS updates these to take into
consideration external amplifiers or other external logic when relevant.
G[0:3] indicates the magnitude of the gain. G[4] indicates whether the value is a
gain or attenuation.
For Gain/Attenuation settings, see Table 23: page73.
These bits are read/write and are not reset on RESET#.
Inversion bit: Indicates that the CODEC presents a 180 degree phase shift to the
signal.
0h - No inversion reported
1h - Inverted
This bit is read/write and is not reset on RESET#.
BIOS should invert for each inverting gain stage.
Buffer delays: CODEC will provide number a delay measurement for the input
and output channels. Software will use this value to accurately calculate audio
stream position with respect to what is been reproduced or recorded. These
values are in 20.83 µs (1/48000 second) units.
For output channels, this timing is from the end of AC Link frame in which the
sample is provided, until the time the analog signal appears at the output pin. For
input streams, this is from when the analog signal is presented at the pin until the
representative sample is provided on the AC Link.
Analog in and out paths are not considered as part of this delay.
The measurement is a “typical” measurement, at a 48 KHz sample rate, with
minimal in-CODEC processing (i.e., 3D effects are turned off.)
00h - Information not provided
01h…1Eh - Buffer delay in 20.83 µs units
1Fh - reserved
These bits are read/write and are not reset on RESET#.
The default value is the delay internal to the CODEC. The BIOS may add to this
value the known delays external to the CODEC, such as for an external
amplifier.
72
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s) Reset Value
4
1
3-1
0
0
NA
Name
Description
Information Valid Bit: Indicates whether a sensing method is provided by the
CODEC and if information field is valid. This field is updated by the CODEC.
0 - After CODEC RESET# de-assertion, it indicates the CODEC does NOT
provides sensing logic and this bit will be Read Only. After a sense cycle is
completed, indicates that no information is provided on the sensing method.
IV
1 - After CODEC RESET# de-assertion, it indicates the CODEC provides
sensing logic for this I/O and this bit is Read/Write. After clearing this bit by
writing 1, when a sense cycle is completed the assertion of this bit indicates that
there is valid information in the remaining descriptor bits. Writing 0 to this bit has
no effect.
BIOS should NOT write this bit, as it is reset on RESET#.
RESERVED Bits not used, should read back 0
Function Information Present
This bit set to a 1 indicates that the G[4:0], INV, DL[4:0] (Register 68h, Page 01h)
FIP
and ST[2:0] (register 6Ah, Page 01h) are supported and R/W capable.
This bit is Read Only.
Table 22. Reg 68h Default Values
Reg 66h Function Code
Reg 68h Default Value
00h Line Out
0010h
01h Headphone Out
05h Mic1
0010h
0010h
06h Mic2
0010h
All other Function Codes
0000h
For RESET#: Reg 68h default value is 0000h.
Table 23. Gain or Attenuation Examples
G[4:0]
00000
Gain or Attenuation (dB relative to level-out)
0 dBV
00001
+1.5 dBV
01111
10001
+24 dBV
-1.5 dBV
11111
-24 dBV
Table 24. Register 68h/Page 01h Bit Overview
8.4.6.
Bit
Bit R/W Overview
D15:D5
Read/Write and only reset on POR (Power on Reset) and not by RESET#.
D4
D3:1
Read/Write and should NOT be set by the BIOS
Reserved
D0
Read Only.
Digital Audio Control (6Ah, Page 00h)
To access Register 6Ah, Page 00h must be selected in Register 24h.
IDT™
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STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Default: 0000h
D15
D14
D13
D7
D6
D5
D12
D11
RESERVED
D4
D3
RESERVED
D10
D9
D8
D2
D1
D0
SPOR
DO1
RSVD
Bit(s) Reset Value
Name
Description
15:3
0
RESERVED Bits not used, should read back 0
Over-ride Register 2Ah, D12 write-lock when SPDIF_EN = 1.
2
0
SPOR
All bits except SPDIF sample-rate are affected (D13-D12). Allows for sub-code
changing on-the-fly.
SPDIF Digital Output Source Selection:
1
0
DO1
DO1 = 0; PCM data from the AC-Link to SPDIF
DO1 = 1; ADC record data to SPDIF
0
0
RESERVED Bits not used, should read back 0
8.4.7.
Sense Details (6Ah Page 01h)
Register 24h must be set to Page 01h to access this register.
Default: NA
D15
ST2
D14
ST1
D13
ST0
D12
S4
D11
S3
D10
S2
D9
S1
D8
S0
D7
D6
D5
D4
D3
D2
D1
D0
OR1
OR0
SR5
SR4
SR3
SR2
SR1
SR1
Bit(s) Reset Value
15-13
12-8
IDT™
Name
Description
Connector/Jack location bits
This field describes the location of the jack in the system.
0h - Rear I/O Panel
1h - Front Panel
ST2:ST0 2h - Motherboard
3h - Dock/External
4h:6h - Reserved
7h - No Connection/unused I/O
These bits are Read/Write.
Sensed bits meaning relates to the I/O being sense as output or inputs.
Sensed bits (outputs): See Table 25: page75.
This field allows for the reporting of the type of output peripheral/device plugged in
the jack. Values specified below should be interrogated in conjunction with the
SR[5:0] and OR[1:0] bits for accurate reporting.
S4:S0
Sensed bits (inputs): See Table 26: page75.
This field allows for the reporting of the type of input peripheral/device plugged in
the jack. Values specified below should be interrogated in conjunction with the
SR[5:0] and OR[1:0] bits for accurate reporting.
This field is Read Only.
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STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s) Reset Value
7-6
5-0
Name
Description
Order Bits. These bits indicate the order the sense result bits SR[5:0] are using.
00 - 100 (i.e., Ohms)
OR1:0 01 - 101 (i.e., 10 Ohms)
10 - 102 (i.e., 100 Ohms)
11 - 103 (i.e., 1K Ohms)
Sense Result bits
SR5:SR0 These bits are used to report a vendor specific fingerprint or value. (Resistance,
impedance, reactance, etc.). This field is Read Only.
Table 25. Sensed Bits (Outputs)
Reported Value
Output Peripheral/Device
0h
Data not valid. Indicates that the reported value(s) is (are) invalid.
1h
2h
No connection. Indicates that there are no connected devices.
Fingerprint. Indicates a specific fingerprint value for devices that are not specified or unknown.
3h
Speakers (8 ohms)
4h
5h
Speakers (4 ohms)
Powered Speakers
6h
Stereo Headphone
7h
8h
Reserved
Reserved
9h
Headset (mono speaker left channel and microphone.)
Ah
Other. Allows a vendor to report sensing other type of devices/peripherals. SR[5:0] together with
OR[1:0] provide information regarding the type of device sensed.
Bh-Eh
Fh
Reserved
Unknown (use fingerprint)
Table 26. Sensed Bits (Inputs)
Reported Value
0h
1h
Data not valid. Indicates that the reported value(s) is (are) invalid.
No connection. Indicates that there are no connected devices.
2h
Fingerprint. Indicates a specific fingerprint value for devices that are not specified.
3h
4h
Microphone (mono)
Reserved
5h
Stereo Line In (CE device attached)
6h
7h
Reserved
Reserved
8h
Reserved
9h
Headset (mono speaker left channel and microphone.)
Other. Allows a vendor to report sensing other type of devices/peripherals. SR[5:0] together with
OR[1:0] provide information regarding the type of device sensed.
Ah
Bh-Eh
Fh
IDT™
Input Peripheral/Device
Reserved
Unknown (use fingerprint)
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
8.4.8.
Revision Code (6Ch)
To access Register 6Ch, Page 00h must be selected in Register 24h.
Default: 00xxh
D15
D14
D13
D12
D11
D10
D9
D8
D2
D1
D0
MINORREV
D7
D6
Bit(s) Reset Value
15:8
00h
7:0
xxh
8.4.9.
D5
D4
D3
MAJORREV
Name
Description
Minor Revision ID. These bits are read only and will be updated based on minor
MINORREV
device changes which will not require software changes.
Major Revision ID. These bits are read only and will be updated based on major
MAJORREV
device changes.
Analog Special (6Eh)
To access Register 6Eh, Page 00h must be selected in Register 24h.
Default: 1000h
D15
D14
D13
RESERVED
D7
RSVD
D6
MUTEFIX
DISABLE
Bit(s) Reset Value
15:13
0
IDT™
D12
D11
D10
AC97MIX
D5
D4
D3
ADCSLT1
ADCSLT0
RSVD
Name
RESERVED
12
1
AC97MIX
11:7
0
RESERVED
6
0
MUTEFIX
DISABLE
5:4
0
ADCSLT1:0
D9
D8
RESERVED
D2
MIC GAIN
VAL
D1
D0
SPLYOVR EN
SPLYOVR VAL
Description
Bits not used, should read back 0
0 = Mixer record contains a mix of all mono and stereo analog input signals,
not the DAC (ALL ANALOG mode).
1 = Mixer record contains a mix of all mono and stereo analog input signals
plus the DAC signal (AC’97 mode).
This bit only has an effect when either Stereo Mix or Mono Mix is selected as
the record source in Reg 1Ah.
The “ALL” mode is useful in conjunction with the POP BYPASS mode (Reg
20h; D15) to record all analog sources, perform further processing in the
digital domain, including combining with other PCM data, and routing through
the DACs directly to Line Out, Headphone Out, or Mono Out.
A Stereo Mix recording will be affected by the setting of the 3D Effects bit
(Reg 20h; D13)
Bits not used, should read back 0
0 = MUTE FIX Enabled
1 = MUTE FIX Disabled
When this bit is zero, and either channel is set to -46.5dB attenuation (1Fh),
then that channel is fully muted. When this bit is one, then operation is per
AC’97 specification.
Select slots for ADC data on ACLINK
00 = Left slot 3, right slot 4
01 = Left slot 7, right slot 8
10 = Left slot 6, right slot 9
11 = Left slot 10, right slot 11
76
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s) Reset Value
3
0
2
0
1
0
0
0
8.4.10.
Name
RESERVED
Description
RESERVED
Adds +10dB gain to the selected MIC input. Use in conjunction with
BOOSTEN (Reg. 0Eh;D6)
BOOSTEN
MICGAINVAL
MIC GAIN VAL 0
0
= 0 dB
0
1
= 10 dB
1
0
= 20 dB
1
1
= 30 dB
Supply Override bit allows override of the supply detect.
SPLYOVR_EN 0 = No override on supply detect
1 = Override supply detect with bit 0
Supply Override Value provides the analog voltage operation values.
SPLYOVR_VA
0 = Force 3.3 v operation
L
1 = Force 5 V operation
Analog Current Adjust (72h)
To unlock Register 72h, write 0xABBA to Register 70h.
Default: 0000h
D15
D14
D7
D6
D13
D12
D11
D10
D9
D8
D5
RESERVED
D4
D3
D2
D1
D0
INT APOP
RESERVED
Bit(s) Reset Value
15:8
0
8.4.11.
7
0
6:0
0
Name
Reserved
Description
Reserved
0 = Anti Pop Enabled
1 = Anti Pop Disabled
The STAC9752/9753 includes an internal power supply anti-pop circuit that
prevents audible clicks and pops from being heard when the CODEC is powered
on and off. This function is accomplished by delaying the charge/discharge of the
VREF capacitor (Pin 27). A CVREF value of 1 µ F will cause a turn-on delay of
INT_APOP roughly 3 seconds, which will allow the power supplies to stabilize before the
CODEC outputs are enabled. The delay will be extended to 30 seconds if a
CVREF value of 10 µ F is used. The CODEC outputs are also kept stable for the
same amount of time at power-off to allow the system to be gracefully turned off.
The Anti Pop bit allows this delay circuit to be bypassed for rapid production
testing. Any external component anti-pop circuit is unaffected by the internal
circuit.
Reserved Reserved
EAPD Access Register (74h)
Default: 0800h
D15
EAPD
D14
D7
D6
D13
RESERVED
D12
D11
EAPD_OEN
D5
D4
D3
RESERVED
IDT™
77
D10
D9
RESERVED
D8
D2
D1
D0
INTDIS
GPIOACC
GPIOSLT12
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Bit(s) Reset Value
15
0
14:12
0
11
1
10:3
0
2
0
1
0
0
0
8.4.12.
Name
Description
EAPD data Enable
EAPD
EAPD data is output on the EAPD pin when bit D11 = 1
EAPD data is input on the EAPD pin when bit D11 = 0
Reserved Bits not used, should read back 0
EAPD Pin Enable
EAPD_OEN 0 = EAPD configured as input pin
1 = EAPD configured as output pin
Reserved Bits not used, should read back 0
Interrupt disable option.
Interrupts cleared by writing a 1 to I4 (Reg24h:D15)
INTDIS
0 = Will clear both SENSE and GPIO interrupts
1 = Will only clear SENSE interrupts. GPIO interrupts will have to be cleared in
Reg54h.
GPIO ACCESS
GPIOACC 0 = ACLINK access from GPIO Pads
1 = ACLINK access from GPIO Register 54h
0 = GPIO0/1 access via Reg 54h when GPIO is set as an output, for input, Slot
12 data will be 0h.
1 = GPIO0/1 access via Slot 12 when GPIO is set as an output, for inputs,
GPIOSLT12
Reg54h will not be updated.
This can only be used if a modem CODEC is not present in the system and using
Slot 12.
High Pass Filter Bypass (78h)
To unlock Register 78h, write 0xABBA to Register 76h.
Default: 0000h
D15
D14
D13
D12
D11
D7
D6
D5
D4
RESERVED
D10
D9
D8
D2
D1
D0
ADC HPF BYP
RESERVED
Bit(s) Reset Value
15:1
0
0
IDT™
0
D3
Name
RESERVED
Description
Bits not used, should read back 0
0 = ADC High Pass Filter active, (Normal operation)
ADC HPF BYP
1 = ADC High Pass Filter Bypass
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STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
8.5.
Vendor ID1 and ID2 (Index 7Ch and 7Eh)
These two registers contain four 8-bit ID codes. The first three codes have been assigned by
Microsoft using their Plug and Play Vendor ID methodology. The fourth code is a manufacturer
assigned code identifying the STAC9752/9753. The ID1 register (index 7Ch) contains the value
8384h, which is the first (83h) and second (84h) bytes of the Microsoft ID code. The ID2 register
(index 7Eh) contains the value 7652h, which is the third (76h) byte of the Microsoft ID code, and 52h
which is the STAC9752/9753 ID code.
8.5.1.
Vendor ID1 (7Ch)
Default: 8384h
8.5.2.
D15
1
D14
0
D13
0
D12
0
D11
0
D10
0
D9
1
D8
1
D7
D6
D5
D4
D3
D2
D1
D0
1
0
0
0
0
1
0
0
D13
D12
D11
D10
D9
D8
Vendor ID2 (7Eh)
Default: 7652h
D15
IDT™
D14
0
1
1
1
0
1
1
0
D7
0
D6
1
D5
0
D4
1
D3
0
D2
0
D1
1
D0
0
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STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
9. LOW POWER MODES
The STAC9752/9753 is capable of operating at reduced power when no activity is required. The
state of power down is controlled by the Powerdown Register (26h). There are 7 commands of separate power down. The power down options are listed in Table 27. The first three bits, PR[2:0], can
be used individually or in combination with each other, and control power distribution to the ADCs,
DACs and Mixer. The last analog power control bit, PR3, affects analog bias and reference voltages,
and can only be used in combination with PR0, PR1, and PR2. PR3 essentially removes power from
all analog sections of the CODEC, and is generally only asserted when the CODEC will not be
needed for long periods. PR0 and PR1 control the PCM ADCs and DACs only. PR2 and PR3 do not
need to be “set” before a PR4, but PR0 and PR1 should be “set” before PR4. PR5 disables the DSP
clock and does not require an external cold reset for recovery. PR6 disables the headphone driver
amplifier for additional analog power saving.
Table 27. Low Power Modes
GRP Bits
Function
PR0
PCM_In ADCs & Input Mux Powerdown
PR1
PR2
PCM_Out DACs Powerdown
Analog Mixer powerdown (VREF still on)
PR3
Analog Mixer powerdown (VREF off)
PR4
PR5
Digital Interface (AC-Link) powerdown (BIT_CLK forced low)
Digital Clock disable, BIT_CLK still on
PR6
Powerdown HEADPHONE_OUT
Figure 22. Example of STAC9752/9753 Powerdown/Powerup flow
PR0=1
Normal
PR1=1
ADCs off PR0
PR0=0 & ADC=1
Ready =1
PR2=1
DACs off PR1
PR1=0 & DAC=1
PR4=1
Analog off
PR2 or PR3
PR2=0 & ANL=1
Default
Digital I/F off
PR4
Shut off
AC-Link
Warm Reset
Cold Reset
The Figure 22 illustrates one example procedure to do a complete powerdown of STAC9752/9753.
From normal operation, sequential writes to the Powerdown Register are performed to power down
STAC9752/9753 a section at a time. After everything has been shut off, a final write (of PR4) can be
executed to shut down the AC-Link. The part will remain in sleep mode with all its registers holding
their static values. To wake up, the AC'97 controller will send an extended pulse on the sync line,
issuing a warm reset. This will restart the AC-Link (resetting PR4 to zero). The STAC9752/9753 can
also be woken up with a cold reset. A cold reset will reset all of the registers to their default states
(Paged Registers are semi-exempt). When a section is powered back on, the Powerdown Control/
Status register (index 26h) should be read to verify that the section is ready (stable) before attempting any operation that requires it.
IDT™
80
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Figure 23. Powerdown/Powerup flow with analog still alive
PR0=1
Normal
PR1=1
ADCs off PR0
PR0=0 & ADC=1
PR4=1
DACs off PR1
PR1=0 & DAC=1
Digital I/F off
PR4
Shut off
AC-Link
Warm Reset
Figure 23 illustrates a state when all the mixers should work with the static volume settings that are
contained in their associated registers. This configuration can be used when playing a CD (or external LINE_IN source) through STAC9752/9753 to the speakers, while most of the system in low
power mode. The procedure for this follows the previous except that the analog mixer is never shut
down.
IDT™
81
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
10. MULTIPLE CODEC SUPPORT
The STAC9752/9753 provides support for the multi-CODEC option according to the Intel AC'97, rev
2.3 specification. By definition, there can be only one Primary CODEC (CODEC ID 00) and up to
three Secondary CODECs (CODEC IDs 01,10, and 11). The CODEC ID functions as a chip select.
Secondary devices therefore have completely orthogonal register sets; each is individually accessible and they do not share registers.
10.1. Primary/Secondary CODEC Selection
In a multi-CODEC environment the CODEC ID is provided by external programming of pins 45 and
46 (CID0 and CID1). The CID pin electrical function is logically inverted from the CODEC ID designation. The corresponding pin state and its associated CODEC ID are listed in the “CODEC ID
Selection” table.
Table 28. CODEC ID Selection
10.1.1.
CID1 State
CID0 State
CODEC ID
CODEC Status
Dvdd or floating
Dvdd or floating
00
Primary
Dvdd or floating
0V
0V
Dvdd or floating
01
10
Secondary
Secondary
0V
0V
11
Secondary
Primary CODEC Operation
As a Primary device, the STAC9752/9753 is completely compatible with existing AC'97 definitions
and extensions. Primary CODEC registers are accessed exactly as defined in the AC'97 Component
Specification and AC'97 Extensions. The STAC9752/9753 operates as Primary by default, and the
external ID pins (45 and 46), have internal pull-ups so that these pins may be left as no-connects for
operation as a primary.
When used as the Primary CODEC, the STAC9752/9753 generates the master AC-Link BIT_CLK
for both the AC'97 Digital Controller and any Secondary CODECs. The STAC9752/9753 can support
up to four loads of 10 KΩ and 50 pF on the BIT_CLK output. This is to ensure that up to four CODEC
implementations will not load down the clock output.
10.1.2.
Secondary CODEC Operation
When the STAC9752/9753 is configured as a Secondary device the BIT_CLK pin is configured as an
input at power up. Using the BIT_CLK provided by the Primary CODEC insures that everything on
the AC-Link will be synchronous. As a Secondary device it can be defined as CODEC ID 01, 10, or
11 in the two-bit field(s) of the Extended Audio and/or Extended Modem ID Register(s).
IDT™
82
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
10.2. Secondary CODEC Register Access Definitions
The AC'97 Digital Controller can independently access Primary and Secondary CODEC registers by
using a 2-bit CODEC ID field (chip select) which is defined as the LSBs of Output Slot 0. For Secondary CODEC access, the AC'97 Digital Controller must invalidate the tag bits for Slot 1 and 2
Command Address and Data (Slot 0, bits 14 and 13) and place a non-zero value (01, 10, or 11) into
the CODEC ID field (Slot 0, bits 1 and 0).
As a Secondary CODEC, the STAC9752/9753 will disregard the Command Address and Command
Data (Slot 0, bits 14 and 13) tag bits when it sees a 2-bit CODEC ID value (Slot 0, bits 1 and 0) that
matches its configuration. In a sense the Secondary CODEC ID field functions as an alternative
Valid Command Address (for Secondary reads and writes) and Command Data (for Secondary
writes) tag indicator.
Secondary CODECs must monitor the Frame Valid bit, and ignore the frame (regardless of the state
of the Secondary CODEC ID bits) if it is not valid. AC'97 Digital Controllers should set the frame valid
bit for a frame with a secondary register access, even if no other bits in the output tag slot except the
Secondary CODEC ID bits are set.
This method is designed to be backward compatible with existing AC'97 controllers and CODECs.
There is no change to output Slot 1 or 2 definitions.
Table 29. Secondary CODEC Register Access Slot 0 Bit Definitions
Output Tag Slot (16-bits)
Bit
Description
15
14
Frame Valid
Slot 1 Valid Command Address bit (†Primary CODEC only)
13
Slot 2 Valid Command Data bit (†Primary CODEC only)
12-3
2
Slot 3-12 Valid bits as defined by AC'97
Reserved (Set to 0)
2-bit CODEC ID field
(00 reserved for Primary; 01, 10, 11 indicate Secondary)
† New definitions for Secondary CODEC Register Access
†1-0
Note:
Using three CODECs typically requires a controller to support SDATA_IN2.
IDT™
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STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
11. TESTABILITY
The STAC9752/9753 has two test modes. One is for ATE in-circuit test and the other is restricted for
manufacturer’s internal use. The STAC9752/9753 enters the ATE in-circuit test mode if
SDATA_OUT is sampled high at the trailing edge of RESET#. Once in the ATE test mode, the digital
AC-Link outputs (BIT_CLK and SDATA_IN) are driven to a high impedance state. This allows ATE
in-circuit testing of the AC'97 controller. Use of the ATE test mode is the recommended means of
removing the CODEC from the AC-Link when another CODEC is to be used as the primary. This
case will never occur during standard operating conditions. Once either of the two test modes have
been entered, the STAC9752/9753 must be issued another RESET# with all AC-Link signals held
low to return to the normal operating mode.
Table 30. Test Mode Activation
11.0.1.
SYNC
SDATA_OUT
Description
0
0
Normal AC'97 operation
0
1
1
0
ATE Test Mode
IDT Internal Test Mode
1
1
Reserved
ATE Test Mode
ATE test mode allows for in-circuit testing to be completed at the board level. For this to work, the
outputs of the device must be driven to a high impedance state (Z). Internal pullups for digital I/O
pins must be disabled in this mode. This mode initiates on the rising edge of RESET# pin. Only a
cold reset will exit the ATE Test Mode.
Table 31. ATE Test Mode Operation
Pin Name
Pin #
Function
Description
SDATA_OUT
5
1
BIT_CLK
6
Z
SDATA_IN
8
Z
SYNC
10
0
RESET#
11
1
N.C.
31
Z
Always an input
N.C.
33
Z
Always an input
N.C.
34
Z
Always an input
GPIO0
43
Z
GPIO1
44
Z
CID0
45
Z
CID1
46
Z
EAPD
47
Z
SPDIF
48
Z
Must be held high at the rising edge of RESET#
Must be held low at rising edge of RESET#
Note: Pins 31, 33, and 34 are NO CONNECTS.
IDT™
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STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
36
35
34
33
32
31
30
29
28
27
26
25
LINE_OUT_R
LINE_OUT_L
NC
NC
CAP2
NC
AFILT2
AFILT1
VREFout
VREF
AVss1
AVdd1
12. PIN DESCRIPTION
37
38
39
40
41
42
43
44
45
46
47
48
24
23
22
21
20
19
18
17
16
15
14
13
48-Pin TQFP
LINE_IN_R
LINE_IN_L
MIC2
MIC1
CD_R
CD_GND
CD_L
VIDEO_R
VIDEO_L
AUX_R
AUX_L
PHONE
DVdd1 1
XTL_IN 2
XTL_OUT 3
DVss1 4
SDATA_OUT 5
BIT_CLK 6
DVss2 7
SDATA_IN 8
DVdd2 9
SYNC 10
RESET# 11
PC_BEEP 12
MONO_OUT
AVdd2
HP_OUT_L
HP_COMM
HP_OUT_R
AVss2
GPIO0
GPIO1
CID0
CID1
EAPD
SPDIF
Figure 24. Pin Description Drawing
Pin 48: To Enable SPDIF, use a 1 KΩ-10 KΩ external pulldown. To Disable SPDIF, use a 1 KΩ- 1 0 KΩ
external pullup. Do NOT leave Pin 48 floating.
The CD_GND signal is an AC signal return for the two CD input channels. It is normally biased at about
2.5V. The name of the pin in the AC97 specification is CD_GND, and this has confused many designers. It should not have any DC path to GND. Connecting the CD_GND signal directly to ground will
change the internal bias of the entire CODEC, and cause serious distortion. If there is no analog CD
input, then this pin can be No-Connect.
IDT™
85
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
12.1. Digital I/O
These signals connect the STAC9752/9753 to its AC'97 controller counterpart, an external crystal,
multi-CODEC selection and external audio amplifier.
Table 32. Digital Connection Signals
Pin Name
Pin #
Type
XTL_IN
2
I
XTL_OUT
3
I/O
SDATA_OUT
5
I
BIT_CLK
6
I/O
12.288 MHz serial data clock
SDATA_IN
8
O
Serial, time division multiplexed, AC'97 output stream
SYNC
10
I
48 KHz fixed rate sample sync
RESET#
11
I
AC'97 Master H/W Reset
N.C.
31
I
IDT Internal Test mode only.
N.C.
33
I
IDT Internal Test mode only
N.C.
34
I/O
IDT Internal Test mode only
GPIO0
43
I/O
General Purpose I/O
GPIO1
44
I/O
General Purpose I/O
CID0
45
I
Multi-CODEC ID select – bit 0
CID1
46
I
Multi-CODEC ID select – bit 1
EAPD
47
I/O
External Amplifier Power Down/GPIO
I/O
SPDIF digital output
Pin 48: To Enable SPDIF, use an 1 KΩ - 10 KΩ external
pulldown. To Disable SPDIF, use an 1 KΩ - 1 0 KΩ external
pullup. Do NOT leave Pin 48 floating.
SPDIF
48
Description
24.576 MHz Crystal or External Clock Source
24.576 MHz Crystal
Serial, time division multiplexed, AC'97 input stream
Note: Pins 31, 33, and 34 are NO CONNECTS.
IDT™
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
12.2. Analog I/O
These signals connect the STAC9752/9753 to analog sources and sinks, including microphones and
speakers.
Table 33. Analog Connection Signals
Pin Name
Pin #
Type
PC_BEEP
12
I*
PC Speaker beep pass-through
PHONE
13
I*
From telephony subsystem speakerphone
AUX_L
14
I*
Aux Left Channel
AUX_R
15
I*
Aux Right Channel
VIDEO_L
16
I*
Video Audio Left Channel
VIDEO_R
17
I*
Video Audio Right Channel
CD_L
18
I*
CD Audio Left Channel
CD_GND
19
I*
CD Audio analog signal return (Do NOT ground. See note. †)
CD_R
20
I*
CD Audio Right Channel
MIC1
21
I*
Desktop Microphone Input
MIC2
22
I*
Second Microphone Input
LINE_IN_L
23
I*
Line In Left Channel
LINE_IN_R
24
I*
Line In Right Channel
LINE_OUT_L
35
O
Line Out Left Channel
LINE_OUT_R
36
O
Line Out Right Channel
MONO_OUT
37
O
To telephony subsystem speakerphone
HP_OUT_L
39
O
Headphone Out Left Channel
HP_COMM
40
O
Headphone Ground Return
HP_OUT_R
41
O
Headphone Out Right Channel
†
Description
Note: * Unused input pins should be tied together and connected to ground through a capacitor (0.1 µF
suggested), except the MIC inputs which should have a separate capacitor to ground.
Note: † The CD_GND signal is an AC signal return for the two CD input channels. It is normally biased at
about 2.5V. The name of the pin in the AC97 specification is CD_GND, and this has confused many
designers. It should not have any DC path to GND. Connecting the CD_GND signal directly to ground
will change the internal bias of the entire CODEC, and cause serious distortion. If there is no analog CD
input, then this pin can be No-Connect.
IDT™
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
12.3. Filter/References
These signals are connected to resistors, capacitors, or specific voltages.
Table 34. Filtering and Voltage References
Signal Name
Pin Number
Type
Description
VREF
27
O
Analog ground (0.45 * Vdd, at 5 V; or 0.41 * Vdd at 3 V)
VREFOUT
28
O
Reference Voltage out 5 mA drive (intended for microphone
bias) (~Vdd/2)
AFILT1
29
O
Anti-Aliasing Filter Cap - ADC left channel
AFILT2
30
O
Anti-Aliasing Filter Cap - ADC right channel
CAP2
32
O
ADC reference Cap
12.4. Power and Ground Signals
Table 35. Power and Ground Signals
IDT™
Pin Name
Pin #
Type
AVdd1
25
I
Analog Vdd = 5.0 V or 3.3 V
AVdd2
38
I
Analog Vdd = 5.0 V or 3.3 V
AVss1
26
I
Analog Gnd
AVss2
42
I
Analog Gnd
DVdd1
1
I
Digital Vdd = 3.3 V
DVdd2
9
I
Digital Vdd = 3.3 V
DVss1
4
I
Digital Gnd
DVss2
7
I
Digital Gnd
88
Description
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
13. ORDERING INFORMATION
Part Number
Package
Temp Range
Supply Range
STAC9752XXTAEyyX
48-pin RoHS QFP 7mm x 7mm x 1.4mm
0° C to +70° C
DVdd = 3.3V, AVdd = 5.0V
STAC9753XXTAEyyX
48-pin RoHS QFP 7mm x 7mm x 1.4mm
0° C to +70° C
DVdd = 3.3V, AVdd = 3.3V
yy = 2 digit revision. Contact Sales for complete ordering number.
Add an “R” to the end of the Part number for Tape and Reel delivery. Minimum order quantitiy is
2ku.
14. PACKAGE DRAWING
A2
D
Key
A
A1
D1
E1
E
b
48 pin LQFP
e
LQFP Dimensions in mm
Min.
Nom.
Max.
A
1.40
1.50
1.60
A1
0.05
0.10
0.15
A2
1.35
1.40
1.45
D
8.80
9.00
9.20
D1
6.90
7.00
7.10
E
8.80
9.00
9.20
E1
6.90
7.00
7.10
L
0.45
0.60
0.75
e
Pin 1
0.50
c
0.09
-
0.20
b
0.17
0.22
0.27
c
IDT™
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STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
15. SOLDER REFLOW PROFILE
15.1. Standard Reflow Profile Data
Note: These devices can be hand soldered at 360 oC for 3 to 5 seconds.
FROM: IPC / JEDEC J-STD-020C “Moisture/Reflow Sensitivity Classification for Nonhermetic Solid
State Surface Mount Devices” (www.jedec.org/download).
Profile Feature
Pb Free Assembly
Average Ramp-Up Rate (Tsmax - Tp)
3 oC / second max
Preheat
Temperature Min (Tsmin )
Temperature Max (Tsmax)
Time (tsmin - ts max)
150 o C
200 o C
60 - 180 seconds
Time maintained above
Temperature (T L)
Time (t L)
217 o C
60 - 150 seconds
Peak / Classification Temperature (Tp)
Time within 5 o C of actual Peak Temperature (tp)
Ramp-Down rate
Time 25 oC to Peak Temperature
See “Package Classification Reflow Temperatures” on page 91.
20 - 40 seconds
6 oC / second max
8 minutes max
Note: All temperatures refer to topside of the package, measured on the package body surface.
Figure 25. Reflow Profile
IDT™
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
15.2. Pb Free Process - Package Classification Reflow Temperatures
IDT™
Package Type
MSL
Reflow Temperature
TQFP 48-pin
3
260 o C*
91
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
16. APPENDIX A: PROGRAMMING REGISTERS
Reg #
Name
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Default
00h
Reset
RSRVD
SE4
SE3
SE2
SE1
SE0
ID9
ID8
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
6A90h
02h
Master Volume
Mute
RSRVD
ML5
ML4
ML3
ML2
ML1
ML0
RESERVED
MR5
MR4
MR3
MR2
MR1
MR0
8000h
04h
HP_OUT
Mixer Volume
Mute
RSRVD HPL5
HPL4
HPL3
HPL2
HPL1
HPL0
RESERVED
HPR5
HPR4
HPR3
HPR2
HPR1
HPR0
8000h
MM5
MM4
MM3
MM2
MM1
MM0
8000h
F7
F6
F0
PV3
PV2
PV1
PV0
RSRVD
0000h
GN4
GN3
GN2
GN1
GN0
8008h
GN4
GN3
GN2
GN1
GN0
8008h
06h
Master Volume Mono
Mute
0Ah
PC_BEEP Volume
Mute
RESERVED
0Ch
Phone volume
Mute
0Eh
Mic Volume
Mute
10h
Line In Volume
Mute
RESERVED
GL4
GL3
GL2
GL1
GL0
RESERVED
GR4
GR3
GR2
GR1
GR0
8808h
12h
CD Volume
Mute
RESERVED
GL4
GL3
GL2
GL1
GL0
RESERVED
GR4
GR3
GR2
GR1
GR0
8808h
14h
Video Volume
Mute
RESERVED
GL4
GL3
GL2
GL1
GL0
RESERVED
GR4
GR3
GR2
GR1
GR0
8808h
16h
AUX Volume
Mute
RESERVED
GL4
GL3
GL2
GL1
GL0
RESERVED
GR4
GR3
GR2
GR1
GR0
8808h
18h
PCM Out Volume
Mute
RESERVED
GL4
GL3
GL2
GL1
GL0
RESERVED
GR4
GR3
GR2
GR1
GR0
8808h
1Ah
Record Select
SL2
SL1
SL0
SR2
SR1
SR0
0000h
1Ch
Record Gain
Mute
GL2
GL1
GL0
GR2
GR1
GR0
8000h
20h
General Purpose
POP
BYP
RSRVD
3D
MIX
MS
X
X
F5
F
F3
F2
F1
RESERVED
RESERVED
RESERVED
RESERVED
GL3
boosten
RESERVED
RSVD
RESERVED
RESERVED
LPBK
RESERVED
22h
3D Control
24h
Audio Int. & Paging
I4
I3
I2
I1
I0
26h
Powerdown Ctrl/Stat
EAPD
PR6
PR5
PR4
PR3
PR2
PR1
PR0
28h
Extended Audio ID
ID1
ID0
RESERVED
REV1
REV0
AMAP
LDAC
SDAC
CDAC
DSA1
LDAC/ SDAC/
RSVD RSVD
CDAC/
RSVD
2Ah
GR3
RESERVED
Extended Audio Control/Status VCFG
DP3
DP2
PG3
PG2
PG1
PG0
0000h
REF
ANL
DAC
ADC
000Fh
DSA0
RSVD
SPDIF
DRA
VRA
0A05h
SPSA1 SPSA0
VRM/
RSVD
SPDIF
DRA/
RSVD
VRA
0400h*
RESERVED
PRL/
RSVD
PRK/
RSVD
PRJ/
RSVD
PRI/
RSVD
SPCV
MADC/
RSVD
0000h
RESERVED
RESERVED
0000h
2Ch
PCM DAC Rate
SR15
SR14
SR13
SR12
SR11
SR10
SR9
SR8
SR7
SR6
SR5
SR4
SR3
SR2
SR1
SR0
BB80h
32h
PCM LR
ADC Rate
SR15
SR14
SR13
SR12
SR11
SR10
SR9
SR8
SR7
SR6
SR5
SR4
SR3
SR2
SR1
SR0
BB80h
3Ah
SPDIF Control
V
DRS
L
CC6
CC5
CC4
CC3
CC2
CC1
CC0
PRE
COPY
#PCM/
AUDIO
PRO
2000h
3Eh
Extended Modem Status
GPIO
0100h
4Ch
GPIO Pin Config
RESERVED
GC1
(GPIO1)
GC0
(GPIO0)
0300h
4Eh
GPIO Pin Polarity/Type
RESERVED
GP1
(GPIO1)
GP0
(GPIO0)
FFFFh
50h
GPIO Pin Sticky
RESERVED
GS1
(GPIO1)
GS0
(GPIO0)
0000h
RESERVED
GW1
(GPIO1)
GW0
(GPIO0)
0000h
RESERVED
GI1
(GPIO1)
GI0
(GPIO0)
0000h
52h
SPSR1 SPSR2
RESERVED
PRA
GPIO Pin Mask
54h
GPIO Pin Status
60h
Page
01h
CODEC Class/Rev
RESERVED
CL4
CL3
CL2
CL1
62h
62h
Page
01h
PCI SVID
PVI15
PVI14
PVI13
PVI12
PVI11
PVI10
RV6
RV5
RV4
RV3
RV2
RV1
RV0
12xxh
PVI9
PVI8
PVI7
PVI6
PVI5
PVI4
PVI3
PVI2
PVI1
PVI0
FFFFh
PI6
PI5
PI4
PI3
PI2
PI1
PI0
FFFFh
FC3
FC2
FC1
FC0
T/R
0000h
FIP
xxxxh
VENDOR RESERVED
PCI SID
PI15
PI14
PI13
PI12
PI11
PI10
66h
66h
Page
01h
RV7
VENDOR RESERVED
64h
64h
Page
01h
CL0
RESERVED
PI9
PI8
PI7
VENDOR RESERVED
Function Select
RESERVED
68h
VENDOR RESERVED
68h
Page
01h
Function Information
6Ah
Digital Audio
Control
6Ah
Page
01h
Sense Details
ST2
ST1
ST0
S4
S3
S2
S1
S0
OR1
OR0
SR5
SR4
6Ch
Revision Code
0
0
0
0
0
0
0
0
0
0
0
0
IDT™
G4
G3
G2
G1
G0
INV
DL4
DL3
DL2
DL1
DL0
IV
RESERVED
RESERVED
92
SPOR
DO1
RSVD
0000h
SR3
SR2
SR1
SR0
NA
x
x
x
x
00xxh
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
Reg #
Name
D15
D14
D13
D12
D11
D10
D9
6Ch
Page
01h
D8
D7
D6
D5
D4
D3
D2
D1
MUTE
FIX
DISABLE
ADC
slot1
ADC
slot0
RSVD
MIC GAIN
VALUE
SPLY
OVR EN
D0
Default
RESERVED
6Eh
Analog Special
AC97
ALL
MIX
RESERVED
RESERVED
6Eh
Page
01h
SPLY OVR 1000h
VAL
RESERVED
70h
VENDOR RESERVED
72h
Analog Current Adjust
74h
EAPD Access
EAPD
EAPD_
OEN
RESERVED
0000h
INT
APOP
RESERVED
RESERVED
RESERVED
76h
INTDIS
0000h
GPIO ACC
GPIO
SLT12
VENDOR RESERVED
78h
High Pass Filter Bypass
0800h
0000h
ADC HPF
BYP
RSESERVED
RESERVED
0000h
7Ah
Reserved
7Ch
Vendor ID1
1
0
0
0
0
0
1
1
1
0
0
0
0
1
0
0
0000h
8384h
7Eh
Vendor ID2 9752
0
1
1
1
0
1
1
0
0
1
0
1
0
0
1
0
7652h
*depends upon chip ID
IDT™
93
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
17. REVISION HISTORY
Revision
Date
Description of Change
3.2
October 2003
-Removed “Preliminary” tag on front page.
-Removed BIT_CLK as an input option from clocking table, it was incorrectly included in 3.1 version.
-Added CD_GND elaboration note on connection diagram, pin list and pin out diagrams:
“The CD_GND signal is an AC signal return for the two CD input channels. It is normally biased at
about 2.5 V. The name of the pin in the AC’97 specification is CD_GND, and this has confused
many designers. It should not have any DC path to GND. Connecting the CD_GND signal directly to
ground will change the internal bias of the entire CODEC, and cause serious distortion. If there is no
analog CD input, then this pin can be No-Connect. “
3.2
3 October 2006
Release in IDT format.
3.3
December 2006
Updated part ordering information to longer orderable part number related to previously issued
PCN.
IDT™
94
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
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© 2006 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are trademarks of Integrated Device
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