CMEDIA CMI-8738

Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
Preliminary
Ver 1.2
CMI-8738/PCI-SX
C3DX PCI-Based HRTF 3D Extension Positional Audio Chip
With high speed PCI V2.1 bus controller and legacy audio
Features
SB16® DSPemulator,CMI8738 is designed for PC add-in cards
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and all-in-one motherboards. No external CODEC is needed in
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HRTF-based 3D positional audio,
supporting DirectSound™ 3D and A3D™
interface
Supports rear side speakers, C3DX
positional audio in 4 CH speaker mode
Legacy audio SBPro™ compatible
DLS-based wavetable music synthesizer,
supports DirectMusic™
Built-in 32ohm Earphone buffer
Drivers support EAX™, Karaoke Echo, Key
Surround sound
MPU-401 port
Dual game port
16-bit full duplex CODEC
4 CH 16-bit DAC
32-bit PCI bus master
External E²PROM interface
Single chip design, +5V, 128 pins QFP
CMI8738: CMI-8738 supports the legacy audio – SB16™, FM
emulator/DLS wavetable music synthesis, and HRTF 3D
positional audio functions.
Being compatible with A3D™ and DirectSound™ 3D, CMI8738
®
meets PC99 requirements
CMI8738 uses HRTF 3D extension technology to enhance
traditional HRTF 3D positional audio by substituting two-speaker
system by four- speaker one (it supports additional 2CH 16-bit
DAC to provide rear side audio). It greatly improves HRTF 3D
positional audio quality and successfully removes the sweet spot
limitations: users can enjoy genuine 3D audio gaming effects,
and don't have to worry about the environmental confinement any
more.
Being outstanding for its full audio functions, competitive price,
and power management, CMI-8738 is the best choice for people
seeking for optimum use of the PC applications.
C-Media licensed HRTF 3D library from Central Research
®
Lab (CRL ), U.K, who provides one of the world's best HRTF
libraries
CMI-8738/PCI Block Diagram
PCI BUS
PCI interface
DMA engine
Earphone
IRQ control
buffer
16-bit CODEC
MPU 401 and
Legacy audio
GAME port
SB16™emulator
LINE
OUT
3D
Surround
14.318Mhz
Rear
L/R
MIC IN
PLL and
Music Synthesizer
timing circuit
HRTF DSP engine
Analog Mixer
MIC AMP
LINE / CD /
AUX / PCPSK
IN
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
1
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
PINOUT
XA28
XA27
GND
VDD
XA26
XA25
XA24
XCBE3
XIDSEL
VDD
GND
XA23
XA22
XA21
XA20
XA19
GND
VDD
XA18
A17
XA16
XCBE2
XFRAME
XIRDY
XTRDY
XDEVSEL
VDD
GND
XSTOP
XPAR
XCBE1
XA15
XA14
XA13
XA12
GND
VDD
XA11
NC
NC
NC
NC
NC
NC
XBIO3
XBIO2
XBIO1
XBIO0
NC
GND
VDD
GND
XINTA
NC
XPRST
XCLK33
XGNT
XREQ
NC
VDD
GND
XA31
XA30
XA29
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
NC
NC
VDDM
DGND
NC
XGD7
XGD6
XGD5
XGD4
XGD3
XGD2
XGD1
XGD0
XRXD
XTXD
XGPBIO
NC
XMBCSZ
XEECS
VDD5V
AGND
AVDD
XMICIN
XPCSPKIN
XAUXR
XAUXL
XLNR
XLNL
XREARR
XREARL
XCDR
XCDL
XCDGND
XRFILT
XLFILT
XADCHR
XADCHL
XADOUTR
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
PINOUT
U1
XADOUTL
XVREF
XINTVREF
AVDD
AGND
NC
NC
NC
XOUT
XIN
VDD
GND
XA0
XA1
XA2
XA3
XA4
XA5
GND
VDD
XA6
XA7
XCBE0
XA8
XA9
XA10
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
CMI8738
CMI8738-037-SX AUDIO CHIP
QFP 128 PINS
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
2
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
PIN DESCRIPTION
DIGITAL PIN DESCRIPTION
PIN
Type
Name
Number
XA31-XA0
XINTA
XPRST
XCLK33
XGNT
XREQ
126-128,1-2,5-7,12-16,19-21,32 I/O
-35,38-41,43-44,47-52
117
O
119
I
120
I
121
I
122
O
XIDSEL
XFRAME
XIRDY
9
23
24
I
I/O
I/O
XTRDY
25
I/O
XDEVSEL
26
I/O
XSTOP
29
I/O
XPAR
30
I/O
XCBE3,2,1,0 8,22,31,42
VDD
GND
XIN
I/O
4,10,18,27,37,45,54,115,124
+5V
3,11,17,28,36,46,53,114,116,12 GND
5
55
I
Definition
PCI bus address and data lines
Interrupt request , active-low.
Reset
PCI bus clock.
Bus master grant, active-low.
Bus master request, tri-state
output, active-low.
ID select, active-high.
Cycle frame, active-low.
Initiator ready, active-low. The bus
master device is ready to transmit
or receive data
Target ready, active-low. The target
device is ready to transmit or
receive data
Device select, active-low. The
target device has decoded the
address of the current transaction
as its own chip select range.
Stop transaction, active-low. The
target device request to the master
to stop the current transaction.
Parity. The pin indicates even parity
across XA31-XA9 and XCBE3-0 for
both address and data phases.
Multiplexed command/byte enable.
These pins indicate cycle type
during the address phase of a
transaction.
Digital and PCI I/O power pin
Digital and PCI I/O ground
XOUT
56
XGD7-XGD4 97-94
O
I
XGD3-XGD0 93-90
I/O
XTXD
XRXD
XBIO3-XBIO
0
VDD5V
VDDM
DGND
XEECS
88
89
109-112
O
I
I/O
14.318Mhz crystal, or external clock
input
14.318Mhz crystal
Game port switch input pin.
Switch D to switch A
Game port resistor input pin.
RC3 to RC0
MIDI transmit data
MIDI receive data
General purpose I/O
83
100
99
84
+5V
+5V
GND
O
Digital and PCI I/O power pin
Digital and PCI I/O power pin
Digital and PCI I/O ground
EEPROM chip select
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
3
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
PIN DESCRIPTION
ANALOG PIN DESCRIPTION
AVDD
AGND
XADOUTL-R
XADCHL-R
XLFILT
XRFILT
XVREF
61,81
60,82
64,65
66,67
68
69
63
+5V
GND
AO1
AI/O
AI/O
AI/O
AI
XINTVREF
XCDL-R
XCDGND
XLNL-R
XAUXL-R
XPCSPKIN
XMICIN
XREARL-R
XGPBIO
XMBCSZ
NC
62
71,72,70
AI
AI
Analog power
Analog ground
Line out
ADC filter
Left channel DAC filter
Right channel DAC filter
Reference Voltage (no use, left it
floating)
Reference Voltage
CD audio differential input
75,76
77,78
79
80
73,74
87
85
57-59,86,98,101-108,113,118,1
23
AI
AI
AI
AI
AI/O
O
I
-
Line in or Rear speaker out
Aux. Line in
PC beep signal
Microphone in
Rear speaker out
General purpose I/O pin
Audio chip select (low:enable)
Reserved
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
4
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings
Ratings
Digital power voltage
Analog power voltage
Operating temperature range
Storage temperature range
Maximum power dissipation
Symbol
VDD
AVDD
TO
TST
PDMAX
Value
VDD±5%
AVDD±5%
0 to 70
-40 to 125
300
Units
V
V
°C
°C
MW
Digital Characteristics
PARAMETER
Input high voltage(PCI I/O)
Input low voltage (PCI I/O)
Output high voltage
Output low voltage
Output buffer current
Symbol
VIH
VIL
VOH
VOL
Min
2.
-0.5
2.4
0.0
Symbol
Avin
Avout
Min
Typ
0.2
5
Max
VDD+0.5
0.8
VDD
0.4
Unit
V
V
V
V
mA
Max
Unit
VRms
VRms
db
Audio Characteristics
PARAMETER
Analog input voltage
Analog output voltage
A-A S/N ratio
A-A THD
ADC S/N ratio
ADC THD
DAC S/N ratio
DAC THD
Microphone input level
Microphone booster
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
20
Fax:886-2-87732211
Typ
1.1
1.1
85
0.09
80
0.1
80
0.1
0.2
0.2
200
20
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
db
%
db
%
mv
db
5
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
Configuration
CMI8738 PCI Configuration Spaces
00h 13F6 : (Vender ID) read only
02h 0111 : (Device ID) read only
04h 0006 : Command
(State after #RST all is “0”)
0 (bit 9) Fast back-to-back enable
0 (bit 8) #SERR enable (R/W)
0 (bit 7) Wait cycle control
0 (bit 6) Parity error response
0 (bit 5) VGA palette snoop
0 (bit 4) Memory write and invalidate enable
0 (bit 3) Special cycles
1 (bit 2) Bus master (R/W)
0 (bit 1) Memory space
1 (bit 0) I/O space (R/W)
06h 0280 : Status
0 (bit 15) Detected Parity Error
0 (bit 14) Signaled System Error
0 (bit 13) Received Master Abort
0 (bit 12) Received Target Abort
0 (bit 11) Signaled Target Abort
01 (bits 10-9) DEVSEL timing 00-fast, 01-medium, 10-slow
0 (bit 8) Data Parity Error Detected
1 (bit 7) Fast Back-to-Back Capable
0 (bit 6) UDF Supported
0 (bit 5) 0-33MHz ,1-66MHZ Capable
00000 (bits 4-0) Reserved
08h 10 : Revision ID
09h 040100 : Audio device
0Ch 00 : Cache Line Size
0Dh 20 : Latency Timer
0Eh 80 : Header Type
0Fh 00 : BIST
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
6
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
Configuration
10h 0000d401 : I/O of length : -65280(ffff0100h) : First Base Address register
14h 00000000 : Uninitialized : Second Base Address register
18h 00000000 : Uninitialized : Third Base Address register
1Ch 00000000 : Uninitialized : Fourth Base Address register
20h 00000000 : Uninitialized : Fifth Base Address register
24h 00000000 : Uninitialized : Sixth Base Address register
28h 00000000 : Cardbus CIS Pointer
2Ch 13f6 : (SubSystem Vender ID) (R/W)
2Eh ffff : SubSystem ID (R/W)
30h 00000000 : Expansion ROM Base Address
34h 00000000 : Reserved
38h 00000000 : Reserved
3Ch 05 : Interrupt Line
3Dh 01 : Interrupt Pin
3Eh 02 : Min Grant
3Fh 18 : Max Latency
DMA Slave Configuration Register(R/W)
PCI Configuration address 40H
Bit(s)
Function
31:16
Reserved
15:4
Slave Base Address 15-4. INTEL VX chipset seleted if Base Address
15:4=000h
3
2:1
Non legacy Extended Addressing
0
=
disabled
1
=
enabled
Transfer Size
00
0
= 8 bit transfer
01 =
16 bit transfer
10 =
32 bit transfer, non legacy
11 =
Reserved
Channel Enable
0
=
disabled
1
=
enabled
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
7
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
PCI register
Internal Register Mapping
Function Control Register 0
Address
Bit(s)
R/W
Name
00H
Description
31-20
Reserved.
19
RST_CH1
Channel1, 1->Reset
(Default 0)
18
RST_CH0
Channel0, 1->Reset
(Default 0)
17
CHEN1
Channel1, 1->Enabled,
0->Disabled.
16
CHEN0
Channel0, 1->Enabled,
0->Disabled.
15-4
Reserved
3
PAUSE1
Channel1, 1->Pause if channel1 is enabled.
2
PAUSE0
Channel0, 1->Pause if channel0 is enabled.
1
CHADC1
Channel 1 , 1->Recording,
0
CHADC0
Channel 0,
0->Playback
1->Recording,
0->Playback
Function Control Register 1
Address
Bit(s)
R/W
Name
31-16
Reserved
15-13
DSFC[2:0]
12-10
04H
Description
DAC Sampling Frequency Select,
0
0
0
5.512 K
0
0
1
11.025 K
0
1
0
22.05 K
0
1
1
44.1 K
1
0
0
8K
1
0
1
16 K
1
1
0
32 K
1
1
1
48 K
ASFC[2:0]
ADC Sampling Frequency Select,
0
0
0
5.512 K
0
0
1
11.025 K
0
1
0
22.05 K
0
1
1
44.1 K
1
0
0
8K
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
8
Ver. 1.2
1
0
1
16 K
1
1
0
32 K
1
1
1
48 K
9-6
Reserved
5
INTRM
4
CMI-8738/PCI-SX AUDIO Specification
BREQ
Interrupt Mask bit for MCB (Master control block) module interrupt.
0
MCB interrupt disabled.
1
MCB interrupt enabled.
If this bit is set low it will prevent the MCB and DAC/ADC block
from accessing the memory.
3
0
Bus Master request disabled(power on state)
1
Bus Master request enabled.
VOICE_EN
2
UART_EN
1
JYSTK_EN
0
This bit enables Legacy Voice device(SB16,FM).
0
Legacy Voice disabled on channel 0.
1
Legacy Voice enabled on channel 0.
This bit enables Legacy UART device.
0
UART disabled
1
UART enabled
This bit enables Legacy Joystick device.
0
Joystick disabled
1
Joystick enabled
Reserved
Channel Format Register
Address
Bit(s)
R/W
08H
Name
Description
31-24
VER[7:0]
PCI Audio subversion for internal indentification. “01”
23-19
Reserved
18
FMOFFSET2
When set 1 and Reg. 24H bit7 ‘FMmute=1’,FM PCM will be forced
to DC value 0002H.
17-16
Reserved
15-14
AdcBitLen[1:0] Sample resolution
13-12
00
16 Bits per sample . (Default)
01
15 Bits per sample.
10
14 Bits per sample.
11
13 Bits per sample.
AdcDacLen[1:0] Sample resolution
00
600nSec per bit in a sample.
01
660nSec per bit in a sample.
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
9
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
10
1.3uSec per bit in a sample. (Default)
11
2.8uSec per bit in a sample.
11
CH1 Ssmple Rate 176K
10
CH1 Sample Rate 88K
9
CH0 Sample Rate 176K
8
CH0 Sample Rate 88K
7-4
reserved
3-2
CH1FMT[1:0]
1-0
Data format of channel 1
00
8 bit Mono mode
01
8 bit Stereo mode
10
16 bit Mono mode
11
16 bit Stereo mode
CH0FMT[1:0]
Data format of channel0
00
8 bit Mono mode
01
8 bit Stereo mode
10
16bit Mono mode
11
16 bit Stereo mode
Interrupt Hold/Clear Register
Address
Bit(s)
R/W
Name
Description
31-19
Reserved
18
TDMA_INT_EN Interrupt hold/clear bits for updating TDMA position
17
0
Interruupt Clear
1
Interrupt Hold if exist.
CH1_INT_EN
16
15-0
Interrupt hold/clear bits for the Channel 1.
0
Interrupt Clear
1
Interrupt Hold if exist.
CH0_INT_EN
0CH
Interrupt hold/clear bits for the Channel 0.
0
Interrupt Clear
1
Interrupt Hold if exist.
Reserved
Interrupt Register
Address
Bit(s)
R/W
Name
Description
31
R
INTR
Interrupt reflected from any sources.
0
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
No interrupt
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
10H
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
1
30-28
Reserved
27
R
VCO
26
R
MCBint
25-17
16
15
14
Interrupt pending
Abort conditions occur during PCI Bus Target/Master Access.
0
No interrupt
0
Interrupt pending
Reserved
R
R
R
13-8
UARTint
This bit is the UART interrupt bit.
0
No UART interrupt
1
UART interrupt pending
LTDMAINT
Interrupt for updating Low Channel TDMA position.
0
No interrupt
1
Interrupt pending
HTDMAINT
Interrupt for updation High Channel TDMA position.
0
No interrupt.
1
Interrupt pending.
Reserved
7
R
XDO46
Direct programming EEPROM interface , read data register
6
R
LHBTOG
High/Low status from DMA CTRL register.
5
R
LegHDMA
Legacy is in High DMA channel.
4
R
LegStereo
Legacy is in Stereo mode.
3
R
Ch1Busy
Channel B Busy.
2
R
Ch0Busy
Channel A Busy.
1
R
Chint1
Channel B Interrupt.
0
R
Chint0
0
No interrupt
1
Interrupt pending
Channel A Interrupt.
0
No interrupt
1
Interrupt pending
Legacy Control/Status Register
Address
Bit(s)
R/W
Name
31
Reserved
30-29
VMPU [1:0]
Description
Base address for MPU401 access
00
Base address : 330h
01
Base address : 320h
10
Base address : 310h
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
14H
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
11
28
Base address : 300h
Reserved
27-26
VSBSEL[1:0]
25-24
FMSEL[1:0]
23-21
Reserved
20
SetRetry
The Base Address Select for SB16 access.
00
Base address: 220h
01
Base address: 240h
10
Base address: 260h
11
Base address: 280h
The Base Address Select for FM access.
00
Base address : 388h
01
Base address : 3C8h
10
Base address : 3E0h
11
Base address : 3E8h
Mode of wait state . 0:legacy I/O wait (default) 1:legacy I/O BUS
retry
19
C_EEACCESS Direct programming EEPROM interface Registers.
18
C_EECS
17
C_EEDI46
16
C_EECK46
15-0
Reserved
Micellaneous Control Register
Address
Bit(s)
R/W
18H
Name
Description
31
PWD
Power Down Mode enabled..
30
RESET
Reset Bus Master/DSP Engine.
29-28
SFIL[1:0]
Four level of filter control at the front end DAC..
27
TX/VX
Which motherboard to work with
0
VX chip sets.
1
TX chip sets.
26
N4SPK3D
25-24
Reserved
23
ENDBDAC
Default low, High will enable Double DAC structure.
22
XCHGDAC
Default low,
21-20
Reserved
19
FM_EN
Hardware copy front channel to rear channel
0
CH0 > Front SPKR,
CH1 > Back SPKR.
1
CH0 > Back SPKR,
CH1 > Front SPKR.
Legacy FM enabled.
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
18-17
Reserved
16
VIDWPDSB
15
Reserved
14
MASK_EN
13
VIDWPDSB
CMI-8738/PCI-SX AUDIO Specification
Sub ID write protect disabled. (default 0)
Activate channel mask on Legacy DMA.
0
Disabled
1
Enabled
Write Protect of HSP Configuration Sub ID.
0
Protect.
1
No protect.
12
SFILENB
Let software contrl filter stepping at the front end DAC.
11-5
Reserved
4
MIDSMP
3-2
UPDDMA[1:0] For every the number of samples to notify updating TDMA position.
Enable 1/2 interpolation at the Front end DAC..
00 Every 2048 samples
01 Every 1024 samples
10 Every 512 samples.
11 Every 256 samples.
1-0
* Notice
TWAIT[1:0]
For controling the length of legacy BUS cycle.
00
3 PCICLK.
01
18 PCICLK.
10
24 PCICLK
11
32 PCICLK
REQ_SQ[2:0]
States of BusRequest Engine.
MM_DATA
Bus Master is using Bus.
MIDLE
Bus Master is not using Bus.
REQA/REQB
Channel 0/1 BusMaster Request.
GNTA/GNTB
Channel 0/1 BusMaster Grant.
ADRQ/BDRQ
Channel 0/1 DMA Request.
ADACK/BDACK
Channel 0/1 DMA Acknoledge.
AIRQ/BIRQ
Channel 0/1 Interrupt.
CX/BX
Channel 0/1 Busy.
T - DMA Position
Address
Bit(s)
R/W
Name
Description
31-16
R
TDMACN T
Current Byte/Word Count of DMA channel.
15-0
R
TDMAADR
Current Address of DMA channel.
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1CH
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Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
Mixer Control / Device Configure Register (can be accessed only by BYTE instruction)
Address
Bit(s)
R/W
Name
Description
7-0
W
SBVR[7:0]
Programmable SB16 version No.
R
DEV[7:0]
Hardwire device version No.
20H
Address 21H
Bit(s)
R/W
Name
Description
7-3
Reserved
2
X_ADPCM
SB16 ADPCM enable,default disabled.
1
PROINV
SBPro Left/Right channel switching.
0
X_SB16
Indicate device active as SB16 compatible, default SB16
Address
Bit(s)
R/W
7-0
Name
Description
IDXdata
Mapping SB compatible mixer INDEX register data port(A2x5h)
Address
Bit(s)
R/W
7-0
R/W
23H
Name
Description
IDXaddr
Mapping SB compatible mixer INDEX register address port(A2x4h)
Address
Bit(s)
22H
24H
Name
Description
7
Fmmute
Mute FM
6
Wsmute
Mute Wave stream
5
SPK4
select four speaker mode(emulate Line in to Line out )
4
Rear2front
exchange rear and front channels’s speaker out
3
Waveinl
Digital Wave recording Left channel
2
Waveinr
Digital Wave recording Right channel
1-0
Reserved
Address
Bit(s)
R/W
Name
Description
7
RAUXREN
Recording source select R-Aux
6
RAUXLEN
Recording source select L_Aux
5
VAUXRM
R-AUX mute control
4
VAUXLM
L-AUX mute control
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
25H
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
3-1
VADMIC[2:0]
Recording MIC volume control
0
MICGAINZ
MIC gain control,default high disable
Bit(s)
R/W
Name
Description
7-4
VAUXL[3:0]
L-AUX volume control
3-0
VAUXR[3:0]
R-AUX volume control
Bit(s)
R/W
Address
26H
Address
27H
Name
Description
0
DMAUTO
SB16 Low/High DMA Auto detect enabled ,When high.
1
Reserved
2
XGPBIO
general purpose bi-direction pin, when high output tri-state
(default LOW)
3
Reserved
4
Reserved
5
XGPO1
general purpose output pin 1,this pin shared with XSPDIFO pin,
and enabled when index reg. F0_bit 0 programmed high.
6-7
Reserved
Mup401
PCI Port
Index address 40-4FH
FM
PCI Port
Index address 50-5FH
Extension Index Register (access from SB compatible mixer port)
Index address F0H
Bit(s)
R/W
Name
Description
7-5
VPHONE[2:0]
Phone volume control
4
VPHOM
Phone mute control
3
VSPKM
PC-Speaker mute control,default high unmute
2
RLOOPREN
Recording R-channel enable
1
RLOOPLEN
Recording L-channel enable
0
VADMIC3
Micphone record boost, default low disable, high enable.
Index address F8-FFH
These 8 registers is used to programming M/N conunter by clock generator
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Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
Channel 0 Frame Register 1
Bit(s)
R/W
Name
Description
31-0
W
BASADDR0
Base address of channel 0.
R
CURADDR0
Current address of channel 0.
Address
80H
Address
84H
Address
88H
Address
8CH
Channel 0 Frame Register 2
Bit(s)
R/W
Name
Description
31-16
W
BASCNT0
Base count of samples at Codec.
15-0
W
BASCNT0
Base count of samples at Bus Master.
31-16
R
CURCNT0
Current count of samples at Codec.
15-0
R
CURCNT0
Current count of samples at Bus Master.
Channel 1 Frame Register 1
Bit(s)
R/W
Name
Description
31-0
W
BASADDR1
Base address of channel 0.
R
CURADDR1
Current address of channel 0.
Channel 1 Frame Register 2
Bit(s)
R/W
Name
Description
31-16
W
BASCNT1
Base count of samples at Codec.
15-0
W
BASCNT1
Base count of samples at Bus Master.
31-16
R
CURCNT1
Current count of samples at Codec.
15-0
R
CURCNT1
Current count of samples at Bus Master.
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Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
Legacy SB compatible mixer
Index D7
D6
D5
0x00
0x04
0x0A
0x22
0x26
0x28
0x2E
0x30
0x31
0x32
0x33
0x34
0x35
0x36
0x37
0x38
0x39
0x3A
0x3B
0x3C
0x3D
0x3E
0x3F
0x40
0x41
0x42
0x43
0x44
0x45
0x46
0x47
0x80
0x81
CMI-8738/PCI-SX AUDIO Specification
D4
D3
D2
D1
D0
Reserved
Wave volume left channel
Wave volume right channel
Mic volume
Master volume left channel
Master volume right channel
FM volume left channel
FM volume right channel
Analog-CD volume left channel Analog-CD volume right channel
Line-in volume left channel
Line-in volume right channel
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
PC spk volume
Output muting controls
Line L Line R CD L
CD R
Mic
Recording left channel controls
FM L
FM R Line L Line R CD L
CD R
Mic
Recording right channel controls
FM L
FM R Line L Line R CD L
CD R
Mic
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
IRQ channel (read only)
IRQ10 IRQ7
IRQ5 IRQ2(9)
16 bit DMA channel (read only)
8 bit DMA channel (read only)
DMA 1 DMA 0
DMA 7
DMA 5
DMA 3
Interrupt status (read only)
MPU-40 16bit
8bit
1
DMA
DMA
0x82
z Please do not write any values into reserved registers
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
Audio Processing Technology
1. Stereo
It is only one-dimensional, as sounds come from (left /right) the physical location of
speakers.
2. Surround (Stereo Expander )
It filters the existing stereo signal to make the sounds fill in the area around the speakers,
and in front of the listener.
Sound sources appear to come from outside the physical
locations of the speakers.
3. Multi-Speaker Surround (Dolby Pro Logic or Digital AC-3)
It uses five speakers instead of two to surround the listener; hence, sound sources come
from five directions and create engaging audio experience.
This surround sound effect,
however, has to be pre-recorded, and it dose not support interactive environment.
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
Audio Processing Technology
4. HRTF 3D Positional 3D (C-Media 3D)
Only this sound processing technology can be called real 3D manifestation, as 3D
usually refers to the three dimensions of X, Y and Z.
This technology allows people to
pin-point the location of sound in the real world (up/down, left/right, front/back)using only
two speakers or a pair of headphones.
This technology also supports interactive 3D
applications to get a real-time placement of sounds via API (application programming
interface) such as Microsoft DirectSound3DTM.
We can also use this technology to
simulate Multi-speaker Surround with two physical speakers to deliver five “virtual"
speakers in the air, surrounding the listener and creating home theater sound
environment.
This is the most economical and the easiest solution to people who would
like to get high performance surround sound but don’t want to spend money in adding
extra speakers.
A physical
speaker
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
A virtual
speaker
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
Audio Processing Technology
5. HRTF 3D Extension Positional (C-Media 3DX)
3D illusion exists because traditional 3D positional audio system assumes the user's
position as the sweet spot to design crosstalk-cancellation circuit; therefore, if the user
wants to have 3D positional audio effects, he can’t move his head or position out of sweet
spot.
Another 3D illusion fails because half the population are compulsive
"head-turners" who will never get 3D audio from two speakers .
To remedy this,
C-Media utilizes HRTF 3D extension technology (C3DX) to enhance traditional HRTF 3D
positional audio by substituting two-speaker system by four-speaker one.
least one or two speakers should be placed
Therefore, at
behind the listener's head to complement
the rear-side effect, thus creating compelling realistic sound.
This technology greatly
improves HRTF 3D positional audio quality, and successfully eliminates the sweet spot
limitation. Users can enjoy the real 3D audio gaming effects, and don't have to worry
about the environmental confinement any more.
A virtual
speaker
A physical
speaker
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
HRTF 3D Positional Audio Technology White-Paper
C3D HRTF Positional Audio Technology
C3D technology uses an audio filter called Head Related Transfer Functions (HRTFs), which
is licensed from CRL®(Central Research Lab).
The basic concept of C3D is: since we can
hear sound three dimensionally in the real world using our two ears, it must be possible to
regenerate the same sound effect from two loud speakers.
What is HRTF ?
HRTF (Head Related Transfer Functions) is a set of audio filters which can vary locations of
sound effects (spatial hearing cues) in three-dimension measured from the listener's
eardrum.
People can use this technology and special digital signal processing to re-create spatial
hearing cues, so as to makes the ears hear a realistic and three-dimensional sounds coming
from a pairs of loud speakers or headphones.
There are several listening cues which allow people to hear
sounds three-dimensionally :
(I).
Spatial Hearing : Primary 3D-cues
1. IAD
The head shadowing effect creates differences in the amplitudes of the sound signals
arriving at each ear from the source.
The effects of diffraction are most noticeable in
the range between about 700 Hz to 8 KHz, where the A and S functions periodically
converge and diverge gently.
This Inter-aural Amplitude difference (IAD) is one of the
primary 3D sound cues.
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Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
HRTF 3D Positional Audio Technology White-Paper
2. ITD
In addition to IAD, there is also a time-of-arrival difference between the left and right
ears(unless the sound source is in one of the pole positions, such as
directly in front,
behind, above and below): this is known as the Inter-aural Time Delay (ITD).
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
HRTF 3D Positional Audio Technology White-Paper
3. Pinna Effects
It has been presumed by several researchers that the convolutions of the pinna create
the spectral features which constitute the 'height' cues.
In practical experiments by
Gardner, in which different parts of the pinna were occluded, and then the ability of a
number of subjects to identify sound source positions at different heights was tested, it
was shown that the different features all contributed by different amounts.
For example,
if the fossa is excluded, then height localization capability is impaired, but not totally
extinguished.
It would be reasonable to conclude that it is the combined effect of the
pinna convolutions which create the various localization cues, and it is not valid - or
logical - to attempt to assign particular spatial capabilities with individual physical
features.
(II).
Spatial Hearing : Secondary 3D-cues (shoulder & local reflections)
In addition to the 'primary' 3D sound cues (IAD, ITD and pinna effects), there are several
additional cues which do contribute to the localization capability; these will be referred to
here as 'secondary' cues, and include shoulder/torso reflections, local room reflections, and
psychological cues.
1. Shoulder / Torso reflections
The presence of a torso attached to an artificial head has the effect of increasing the
pressure in the vicinity of the ear up to frequencies of around 2 kHz.
for frontal sources than lateral ones.
The effect is greater
In experience, the presence of the torso does not
appear to contribute much to spatial accuracy.
However, shoulders are located very close
to the ears, and their effect is greater, this time, in respect of
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Ver. 1.2
lateral sounds.
CMI-8738/PCI-SX AUDIO Specification
HRTF 3D Positional Audio Technology White-Paper
If one listens to an artificial head first without - and then with - shoulder
fitments, then it is clear that the shoulders do contribute to spatial effects in certain positions.
The shoulders provide a strong reflection from lateral sources, with a short path-length of
around 10 cm between direct sound and reflection.
The effects are most important for
side-positioned sources, especially for "height" effects, where the shoulders tend to mask
sources which move below about 30 degree depression.
2. Local, Room Reflections
In simulations, it is clear that the incorporation of first-order simulated room reflections can
help in the creation of sound images which have a "solid" nature.
accurately simulated - are relatively slight.
However, the effects - if
Experience has shown that it is primarily the
quality of the HRTFs themselves which determine the quality and solidity of the sound image.
The further addition of second-order reflections does not help significantly, because in reality,
there is a great number of reflections in the average room.
A method which does help to
recreate the acoustic experience of a room, however, is to use approximate simulations of
lateral reverb, using either 2 or 4 laterally placed "virtual" sources at, say, +-70 degrees and
80 degrees azimuth.
•
The quality of the sound image relates to the HRTFs used.
•
The quality of the room image relates to addition of reflections and reverb.
3. Psychological Cues
There are clearly psychological cues present in everyday life which work together with the
audio cues to tell us about the world around us.
For example, if you hear the sound of a
helicopter flying, you expect it to be up in the air, and not downwards.
If a dog is barking
nearby, you would expect it to be downwards.
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
HRTF 3D Positional Audio Technology White-Paper
How to listen to C3D sound correctly and properly?
1. Use Headphones to Have Much Better Effect
When you use headphones in listening, there will be less interference such as outside voices
or room reflections comparing to using speakers.
2. Choose Correct Output Devices
Choose the correct output devices in the options of demo program in accordance with what
listening devices you want to listen to.
Listening through speakers must be proceeded by
crosstalk-cancellation, so if you choose the wrong output devices, there won’t be any 3D
positional audio effect.
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
HRTF 3D Positional Audio Technology White-Paper
3. Position of Speakers
If you listen from speakers, please do not reverse the left and right speakers, which should
be put in equal distance from the listener.
That is, the listener, the left, and the right
speaker must be in the topmost of a right triangle. The position of the listener is called the
“sweet spot”. In addition, the height of the listener’s ears must be equal to that of the
speakers.
4. Turn Surround Sound Functions off
When the surround sound effect is enabled, it will cause confusion with C3D sound, and
make positional sound effect invalid.
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
Audio Rack Panel
Audio Rack Panel
Two Speakers System :
Line-In becomes
Rear Speakers Output
Four Speakers System :
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Fax:886-2-87732211
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4 Speakers
system Enable
Ver. 1.2
CMI-8738/PCI-SX AUDIO Specification
CMI8738 PCI Audio Adapter Layout Notes
1. The wires of analog circuits(chip pin64-80) must be wider than 12mil.
2. The whole PCB grounding should be well-organized(The ground must be placed
as much as possible. Also, the ground of both the component and the solder
sides should be drilled as much as possible.).
3. The grounding under CMI8738 should be well-organized as mentioned above.
4. The regulator(78L05) must be placed near the chip as much as possible.
5. The chip and the circuits need independent power supply regulators to prevent
insufficient currents.
C-MEDIA ELECTRONICS INC. Tel:886-2-87731100
Fax:886-2-87732211
URL : www.cmedia.com.tw
Products and company names mentioned here are the trademarks of their respective owners.