AD ADAU1702

SigmaDSP® 28-/56-Bit Audio Processor
with Two ADCs and Four DACs
ADAU1702
FEATURES
GENERAL DESCRIPTION
28-/56-bit, 25 MIPS digital audio processor
Two ADCs: SNR of 100 dB, THD + N of −83 dB
Four DACs: SNR of 104 dB, THD + N of −90 dB
Complete standalone operation
Self-boot from serial EEPROM
Auxiliary ADC with 4-input mux for analog control
GPIOs for digital controls and outputs
Fully programmable with SigmaStudio™ graphical tool
28-bit × 28-bit multiplier with 56-bit accumulator for full
double-precision processing
Clock oscillator for generating master clock from crystal
PLL for generating master clock from 64 × fS, 256 × fS,
384 × fS, or 512 × fS clocks
Flexible serial data input/output ports with I2S-compatible,
left-justified, right-justified, and TDM modes
Sampling rates up to 192 kHz supported
On-chip voltage regulator for compatibility with 3.3 V systems
48-lead, plastic LQFP
The ADAU1702 is a complete single-chip audio system with a
28-/56-bit audio DSP, ADCs, DACs, and microcontroller-like
control interfaces. Signal processing includes equalization, crossover, bass enhancement, multiband dynamics processing, delay
compensation, speaker compensation, and stereo image widening
and can be used to compensate for real-world limitations of
speakers, amplifiers, and listening environments, providing a
dramatic improvements of perceived audio quality.
Its signal processing is comparable to that found in high
end studio equipment. Most processing is done in full 56-bit,
double-precision mode, resulting in very good low level signal
performance. The ADAU1702 is a fully programmable DSP. The
easy to use SigmaStudio software allows the user to graphically
configure a custom signal processing flow using blocks such as
biquad filters, dynamics processors, level controls, and GPIO
interface controls.
APPLICATIONS
ADAU1702 programs can be loaded on power-up either from a
serial EEPROM through its own self-boot mechanism or from
an external microcontroller. On power-down, the current state
of the parameters can be written back to the EEPROM from the
ADAU1702 to be recalled the next time the program is run.
Multimedia speaker systems
MP3 player speaker docks
Automotive head units
Minicomponent stereos
Digital televisions
Studio monitors
Speaker crossovers
Musical instrument effects processors
In-seat sound systems (aircraft/motor coaches)
Two Σ-Δ ADCs and four Σ-Δ DACs provide a 98.5 dB analog
input to analog output dynamic. Each ADC has a THD + N of
−83 dB, and each DAC has a THD + N of −90 dB. Digital input
and output ports allow a glueless connection to additional
ADCs and DACs. The ADAU1702 communicates through an
I2C® bus or a 4-wire SPI® port.
FUNCTIONAL BLOCK DIAGRAM
PLL
DIGITAL DIGITAL ANALOG ANALOG PLL LOOP
VDD
GROUND VDD GROUND MODE FILTER
3.3V
3
3
3
3
CRYSTAL
3
1.8V
REGULATOR
2
CLOCK
OSCILLATOR
PLL
ADAU1702
2-CHANNEL
ANALOG
INPUT
FILTA/
ADC_RES
2
DAC
STEREO
ADC
28-/56-BIT, 25MIPS
AUDIO PROCESSOR CORE
10ms DELAY MEMORY
2
RESET/
MODE
SELECT
CONTROL
INTERFACE
AND
SELFBOOT
8-CH
DIGITAL
INPUT
8-BIT
AUX
ADC
DAC
FILTD/CM
4-CHANNEL
ANALOG
OUTPUT
8-CH
DIGITAL
OUTPUT
GPIO
INPUT/OUTPUT MATRIX
SELF
BOOT
I2C/SPI
AND
WRITEBACK
4
DIGITAL IN
OR
GPIO
4
4
AUX ADC DIGITAL OUT
OR
OR
GPIO
GPIO
05798-001
5
RESET
Figure 1.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2006 Analog Devices, Inc. All rights reserved.
ADAU1702
TABLE OF CONTENTS
Features .............................................................................................. 1
RAMs and Registers....................................................................... 29
Applications....................................................................................... 1
Address Maps.............................................................................. 29
General Description ......................................................................... 1
Parameter RAM.......................................................................... 29
Functional Block Diagram .............................................................. 1
Data RAM ................................................................................... 29
Revision History ............................................................................... 2
Read/Write Data Formats ......................................................... 29
Specifications..................................................................................... 3
Control Register Map..................................................................... 31
Analog Performance .................................................................... 3
Control Register Details ................................................................ 33
Digital Input/Output.................................................................... 4
2048 to 2055 (0x0800 to 0x0807)—Interface Registers......... 33
Power.............................................................................................. 4
2056 (0x808)—GPIO Pin Setting Register.............................. 34
Temperature Range ...................................................................... 4
PLL and Oscillator........................................................................ 4
2057 to 2060 (0x809 to 0x80C)—
Auxiliary ADC Data Registers.................................................. 35
Regulator........................................................................................ 5
2064 to 2068 (0x0810 to 0x814)—Safeload Data Registers.........36
Digital Timing Specifications ..................................................... 5
2069 to 2073 (0x0815 to 0x819) Safeload Address Registers ......36
Digital Timing Diagrams................................................................. 7
2074 to 2075 (0x081A to 0x081B)—Data Capture Registers......37
Absolute Maximum Ratings............................................................ 9
2076 (0x081C)—DSP Core Control Register ......................... 38
Thermal Resistance ...................................................................... 9
2078 (0x081E)—Serial Output Control Register ................... 39
ESD Caution.................................................................................. 9
2079 (0x081F)—Serial Input Control Register....................... 40
Pin Configuration and Function Descriptions........................... 10
2080 to 2081 (0x0820 to 0x0821)—
Multipurpose Pin Configuration Registers............................. 41
Typical Performance Characteristics ........................................... 13
System Block Diagram ................................................................... 14
Overview.......................................................................................... 15
Initialization .................................................................................... 16
Power-Up Sequence ................................................................... 16
Control Registers Setup ............................................................. 16
Recommended Program/Parameter Loading Procedure ..... 16
Power-Reduction Modes ........................................................... 16
Using the Oscillator.................................................................... 17
Setting Master Clock/PLL Mode .............................................. 17
Voltage Regulator ....................................................................... 18
Audio ADCs .................................................................................... 19
Audio DACs .................................................................................... 20
Control Ports................................................................................... 21
I2C Port ........................................................................................ 22
SPI Port ........................................................................................ 25
Self-Boot ...................................................................................... 26
Signal Processing ............................................................................ 28
2082 (0x0822)—Auxiliary ADC and Power Control ............ 42
2084 (0x0824)—Auxiliary ADC Enable.................................. 42
2086 (0x0826)—Oscillator Power-Down................................ 42
2087 (0x0827)—DAC Setup...................................................... 43
Multipurpose Pins .......................................................................... 44
Auxiliary ADC............................................................................ 44
General-Purpose Input/Output Pins....................................... 44
Serial Data Input/Output Ports ................................................ 44
Layout Recommendations............................................................. 47
Parts Placement .......................................................................... 47
Grounding ................................................................................... 47
Typical Application Schematics.................................................... 48
Self-Boot Mode........................................................................... 48
I2C Control .................................................................................. 49
SPI Control.................................................................................. 50
Outline Dimensions ....................................................................... 51
Ordering Guide .......................................................................... 51
Numeric Formats........................................................................ 28
Programming .............................................................................. 28
REVISION HISTORY
10/06—Revision 0: Initial Version
Rev. 0 | Page 2 of 52
ADAU1702
SPECIFICATIONS
AVDD = 3.3 V, DVDD = 1.8 V, PVDD = 3.3 V, IOVDD = 3.3 V, ambient temperature 25° C, master clock input 12.288 MHz, unless
otherwise noted .
ANALOG PERFORMANCE
Table 1.
Parameter
ADC INPUTS
Number of Channels
Resolution
Full-Scale Input
Signal-to-Noise Ratio
A-Weighted
Dynamic Range
A-Weighted
Total Harmonic Distortion + Noise
Interchannel Gain Mismatch
Crosstalk
DC Bias
Gain Error
DAC OUTPUTS
Number of Channels
Resolution
Full-Scale Analog Output
Signal-to-Noise Ratio
A-Weighted
Dynamic Range
A-Weighted
Total Harmonic Distortion + Noise
Crosstalk
Interchannel Gain Mismatch
Gain Error
DC Bias
VOLTAGE REFERENCE
Absolute Voltage (CM, FILTA, FILTD)
AUXILIARY ADC
Full-Scale Analog Input
INL
DNL
Offset
Input Impedance
Min
Typ
Max
Unit
2
24
100 (283)
Bits
μArms (μAp-p)
100
dB
100
−83
25
−82
1.5
dB
dB
mdB
dB
V
%
Test Conditions/Comments
Stereo input
2 Vrms input with 20 kΩ (18 kΩ external + 2 kΩ
internal) series resistor
−60 dB with respect to full-scale analog input
95
−11
250
+11
4
24
0.9 (2.5)
Bits
Vrms (VP-P)
104
dB
104
−90
−100
25
1.5
dB
dB
dB
mdB
%
V
1.5
V
3.0
0.5
1.0
15
30
V
LSB
LSB
mV
kΩ
−3 dB with respect to full-scale analog input
Analog channel-to-channel crosstalk
Two stereo output channels
−60 dB with respect to full-scale analog output
99
−10
250
+10
Rev. 0 | Page 3 of 52
−1 dB with respect to full-scale analog output
Analog channel-to-channel crosstalk
ADAU1702
DIGITAL INPUT/OUTPUT
Table 2.
Parameter
Input Voltage, High (VIH)
Input Voltage, Low (VIL)
Input Leakage, High (IIH)
Input Leakage, Low (IIL)
Bidirectional Pin Pull-Up Current, Low
MCLKI Input Leakage, High (IIH)
MCLKI Input Leakage, Low (IIL)
High Level Output Voltage (VOH), IOH = 2 mA
Low Level Output Voltage (VOL), IOL = 2 mA
Input Capacitance
GPIO Output Drive
Min
2.0
Typ
Max
IOVDD
0.8
1
1
150
3
3
2.0
0.8
5
2
Unit
V
V
μA
μA
μA
μA
μA
V
V
pF
mA
Comments
Excluding MCLKI
Excluding MCLKI and bidirectional pins
POWER
Table 3.
Parameter
SUPPLY VOLTAGE
Analog Voltage
Digital Voltage
PLL Voltage
IOVDD Voltage
SUPPLY CURRENT
Analog Current (AVDD and PVDD)
Digital Current (DVDD)
Analog Current, Reset
Digital Current, Reset
DISSIPATION
Operation (AVDD, DVDD, PVDD) 2
Reset, All Supplies
POWER SUPPLY REJECTION RATIO (PSRR)
1 kHz, 200 mVP-P Signal at AVDD
Min
Typ
Max 1
3.3
1.8
3.3
3.3
50
40
35
1.5
Unit
V
V
V
V
85
60
55
4.5
mA
mA
mA
mA
286.5
118
mW
mW
50
dB
Maximum specifications are measured across a temperature range of −40°C to +130°C (case) and across a DVDD range of 1.62 V to 1.98 V and an AVDD range of 2.97 V
to 3.63 V.
2
Power dissipation does not include IOVDD power because the current drawn from this supply is dependent on the loads at the digital output pins.
1
TEMPERATURE RANGE
Table 4.
Parameter
Functionality Guaranteed
Min
0°C
Typ
Max
70°C
Unit
°C ambient
PLL AND OSCILLATOR
Table 5.
Parameter
PLL Operating Range
PLL Lock Time
Crystal Oscillator gm
(Transconductance)
Min
MCLK_Nom − 20%
Typ
Max
MCLK_Nom + 20%
Unit
MHz
20
ms
mmho
78
Rev. 0 | Page 4 of 52
Comments
MCLK_Nom is the nominal input in a
given mode (for example, 12.288 MHz in
256 × fS mode with a fs of 48 kHz)
ADAU1702
REGULATOR
Table 6. Regulator 1
Parameter
DVDD Voltage
1
Min
1.7
Typ
1.8
Max
1.84
Unit
V
Regulator specifications are calculated using a Zetex Semiconductors FZT953 transistor in the circuit.
DIGITAL TIMING SPECIFICATIONS
Table 7. Digital Timing 1
Parameter
MASTER CLOCK
tMP
tMP
tMP
tMP
SERIAL PORT
tBIL
tBIH
tLIS
tLIH
tSIS
tSIH
tLOS
tLOH
tTS
tSODS
tSODM
SPI PORT
fCCLK
tCCPL
tCCPH
tCLS
tCLH
tCLPH
tCDS
tCDH
tCOD
I2C PORT
fSCL
tSCLH
tSCLL
tSCS
tSCH
tDS
tSCR
tSCF
tSDR
tSDF
tBFT
TMIN
Limit
TMAX
36
48
73
291
Unit
Description
244
366
488
1953
ns
ns
ns
ns
MCLK period, 512 fS mode.
MCLK period, 384 fS mode.
MCLK period, 256 fS mode.
MCLK period, 64 fS mode.
5
40
40
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
INPUT_BCLK low pulse width.
INPUT_BCLK high pulse width.
INPUT_LRCLK setup. Time to INPUT_BCLK rising.
INPUT_LRCLK hold. Time from INPUT_BCLK rising.
SDATA_INx setup. Time to BCLK_IN rising.
SDATA_INx hold. Time from BCLK_IN rising.
OUTPUT_LRCLK setup in slave mode.
OUTPUT_LRCLK hold in slave mode.
OUTPUT_BCLK falling to OUTPUT_LRCLK timing skew.
SDATA_OUTx delay. Time from OUTPUT_BCLK falling in slave mode.
SDATA_OUTx delay. Time from OUTPUT_BCLK falling in master mode.
MHz
ns
ns
ns
ns
ns
ns
ns
ns
CCLK frequency.
CCLK pulse width low.
CCLK pulse width high.
CLATCH setup. Time to CCLK rising.
CLATCH hold. Time from CCLK rising.
CLATCH pulse width high.
CDATA setup. Time to CCLK rising.
CDATA hold. Time from CCLK rising.
COUT delay. Time from CCLK falling.
kHz
μs
μs
μs
μs
ns
ns
ns
ns
ns
SCL frequency.
SCL high.
SCL low.
Setup time, relevant for repeated start condition.
Hold time. After this period, the first clock is generated.
Data setup time.
SCL rise time.
SCL fall time.
SDA rise time.
SDA fall time.
Bus-free time. Time between stop and start.
40
40
10
10
10
10
10
10
6.25
80
80
0
100
80
0
80
101
400
0.6
1.3
0.6
0.6
100
300
300
300
300
0.6
Rev. 0 | Page 5 of 52
ADAU1702
Parameter
MULTIPURPOSE PINS AND RESET
tGRT
tGFT
tGIL
tRLPW
1
TMIN
Limit
TMAX
50
50
1.5 ×
1/fS
20
Unit
Description
ns
ns
μs
GPIO rise time.
GPIO fall time.
GPIO input latency. Time until high/low value is read by core.
ns
RESET low pulse width.
All timing specifications are given for the default (I2S) states of the serial input port and the serial output port (see Table 66).
Rev. 0 | Page 6 of 52
ADAU1702
DIGITAL TIMING DIAGRAMS
tLIH
tBIH
BCLK_IN
tBIL
tLIS
LRCLK_IN
tSIS
SDATA_INX
LEFT-JUSTIFIED
MODE
MSB
MSB–1
tSIH
tSIS
SDATA_INX
I2S MODE
MSB
tSIH
tSIS
tSIS
SDATA_INX
RIGHT-JUSTIFIED
MODE
LSB
MSB
tSIH
tSIH
8-BIT CLOCKS
(24-BIT DATA)
12-BIT CLOCKS
(20-BIT DATA)
05798-026
14-BIT CLOCKS
(18-BIT DATA)
16-BIT CLOCKS
(16-BIT DATA)
Figure 2. Serial Input Port Timing
tLCH
tBIH
tTS
BCLK_OUTX
tBIL
tLOS
LRCLK_OUTX
SDATA_OUTX
I2S MODE
tSODS
tSODM
MSB
MSB–1
tSODS
tSODM
MSB
tSODS
tSODM
SDATA_OUTX
RIGHT-JUSTIFIED
MODE
MSB
LSB
8-BIT CLOCKS
(24-BIT DATA)
12-BIT CLOCKS
(20-BIT DATA)
14-BIT CLOCKS
(18-BIT DATA)
05798-027
SDATA_OUTX
LEFT-JUSTIFIED
MODE
16-BIT CLOCKS
(16-BIT DATA)
Figure 3. Serial Output Port Timing
Rev. 0 | Page 7 of 52
ADAU1702
tCLS
tCLH
tCLPH
tCCPL
tCCPH
CLATCH
CCLK
CDATA
tCDH
tCDS
COUT
05798-028
tCOD
Figure 4. SPI Port Timing
tDS
tSCH
tSCH
SDA
tSCLH
SCLK
tSCLL
tSCS
tSCF
tBFT
05798-029
tSCR
2
Figure 5. I C Port Timing
tMP
RESET
tRLPW
Figure 6. Master Clock and RESET Timing
Rev. 0 | Page 8 of 52
05798-030
MCLK
ADAU1702
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
Table 8.
Parameter
DVDD to GND
AVDD to GND
IOVDD to GND
Digital Inputs
Maximum Junction Temperature
Storage Temperature Range
Soldering (10 sec)
Rating
0 V to 2.2 V
0 V to 4.0 V
0 V to 4.0 V
DGND − 0.3 V, IOVDD + 0.3 V
135°C
−65°C to +150°C
300°C
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Table 9. Thermal Resistance
Package Type
48-Lead LQFP
ESD CAUTION
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Rev. 0 | Page 9 of 52
θJA
72
θJC
19.5
Unit
°C/W
ADAU1702
AGND
PLL_MODE0
PLL_MODE1
CM
FILTD
AGND
VOUT3
VOUT2
VOUT1
VOUT0
FILTA
AVDD
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
48 47 46 45 44 43 42 41 40 39 38 37
AGND
1
ADC1
2
ADC_RES
36
AVDD
35
PLL_LF
3
34
PVDD
ADC0
4
33
PGND
RESET
5
32
MCLKI
31
OSCO
30
RSVD
PIN 1
INDICATOR
ADAU1702
TOP VIEW
(Not to Scale)
SELFBOOT 6
ADDR0 7
MP4
8
29
MP2
MP5
9
28
MP3
MP1 10
MP0 11
27
MP8
26
MP9
DGND 12
25
DGND
05798-002
DVDD
SCL/CCLK
SDA/COUT
CLATCH/WP
ADDR1/CDATA/WB
MP11
IOVDD
VDRIVE
MP10
MP6
MP7
DVDD
13 14 15 16 17 18 19 20 21 22 23 24
Figure 7. 48-Lead LQFP Pin Configuration
Table 10. Pin Function Descriptions
Pin No.
1, 37, 42
Mnemonic
AGND
Type 1
PWR
Page No.
2
ADC1
A_IN
19
3
ADC_RES
A_IN
19
4
ADC0
A_IN
19
5
RESET
D_IN
6
SELFBOOT
D_IN
26
7
ADDR0
D_IN
22
8
9
10
11
12, 25
MP4
MP5
MP1
MP0
DGND
D_IO
D_IO
D_IO
D_IO
PWR
44
44
44
44
13, 24
DVDD
PWR
Description
Analog Ground Pin. The AGND, DGND, and PGND pins can be tied directly
together in a common ground plane. AGND should be decoupled to an
AVDD pin with a 100 nF capacitor.
Analog Audio Input 1. Full-scale 100 μArms input. Current input allows input
voltage level to be scaled with an external resistor. An 18 kΩ resistor gives a
2 Vrms full-scale input.
ADC Reference Current. The full-scale current of the ADCs can be set with an
external 18 kΩ resistor connected between this pin and ground.
Analog Audio Input 0. Full-scale 100 μArms input. Current input allows input
voltage level to be scaled with an external resistor. An 18 kΩ resistor gives a
2 Vrms full-scale input.
Active Low Reset Input. Reset is triggered on a high-to-low edge and the
ADAU1702 exits reset on a low-to-high edge. For more information about
initialization, see the Power-Up Sequence section.
Enable/Disable Self-Boot. SELFBOOT selects control port (low) or self-boot
(high). Setting this pin high initiates a self-boot operation when the ADAU1702
is brought out of reset. This pin can be tied directly to the control voltage or
pulled up/down with a resistor.
I2C and SPI Address 0. In combination with ADDR1, this pin allows up to four
ADAU1702s to be used on the same I2C bus and up to two ICs to be used
with a common SPI CLATCH signal.
Multipurpose GPIO or Serial Input Port LRCLK (INPUT_LRCLK).
Multipurpose GPIO or Serial Input Port BCLK (INPUT_BCLK).
Multipurpose GPIO or Serial Input Port Data 1 (SDATA_IN0).
Multipurpose GPIO or Serial Input Port Data 0 (SDATA_IN1).
Digital Ground Pin. The AGND, DGND, and PGND pins can be tied directly
together in a common ground plane. DGND should be decoupled to a
DVDD pin with a 100 nF capacitor.
1.8 V Digital Supply. This can be supplied either externally or generated
from a 3.3 V supply with the on-board 1.8 V regulator. DVDD should be
decoupled to DGND with a 100 nF capacitor.
Rev. 0 | Page 10 of 52
ADAU1702
Pin No.
14
15
Mnemonic
MP7
MP6
Type 1
D_IO
D_IO
Page No.
44
44
16
17
MP10
VDRIVE
D_IO
A_OUT
44
5
18
IOVDD
PWR
19
20
MP11
ADDR1/CDATA/WB
D_IO
D_IN
44
22, 24, 26
21
CLATCH/WP
D_IO
24, 26
22
SDA/COUT
D_IO
21, 24
23
SCL/CCLK
D_IO
21, 24
26
MP9
D_IO/A_IO
44
27
MP8
D_IO/A_IO
44
28
MP3
D_IO/A_IO
44
29
MP2
D_IO/A_IO
44
30
31
RSVD
OSCO
X
D_OUT
17
32
MCLKI
D_IN
17
33
PGND
PWR
34
PVDD
PWR
35
PLL_LF
A_OUT
17
36, 48
38
AVDD
PLL_MODE0
PWR
D_IN
17
Description
Multipurpose GPIO or Serial Output Port Data 1 (SDATA_OUT1).
Multipurpose GPIO, Serial Output Port Data 0, or TDM Data Output
(SDATA_OUT0).
Multipurpose GPIO or Serial Output Port LRCLK (OUTPUT_LRCLK).
Drive for 1.8 V Regulator. The base of the voltage regulator external PNP
transistor is driven from VDRIVE.
Supply for Input and Output Pins. The voltage on this pin sets the highest
input voltage that should be seen on the digital input pins. This pin is also
the supply for the digital output signals on the control port and MP pins.
IOVDD should always be set to 3.3 V. The current draw of this pin is variable
because it is dependent on the loads of the digital outputs.
Multipurpose GPIO or Serial Output Port BCLK (OUTPUT_BCLK).
ADDR1: I2C Address 1. In combination with ADDR0, this sets the I2C address
of the IC so that four ADAU1702s can be used on the same I2C bus.
CDATA: SPI Data Input.
WB: EEPROM Writeback Trigger. A rising (default) or falling (if set in the
EEPROM messages) edge on this pin triggers a writeback of the interface
registers to the external EEPROM. This function can be used to save
parameter data on power-down.
CLATCH: SPI Latch Signal. Must go low at the beginning of an SPI transaction
and high at the end of a transaction. Each SPI transaction can take a different
number of CCLKs to complete, depending on the address and read/write bit
that are sent at the beginning of the SPI transaction.
WP: Self-Boot EEPROM Write Protect. This pin is an open-collector output
when in self-boot mode. The ADAU1702 pulls this low to prohibit writes to
an external EEPROM. This pin should be pulled high to 3.3 V.
SDA: I2C Data. This pin is a bidirectional open-collector. The line connected
to this pin should have a 2.2 kΩ pull-up resistor.
COUT: This SPI data output is used for reading back registers and memory
locations. It is three-stated when an SPI read is not active.
SCL: I2C Clock. This pin is always an open-collector input when in I2C control
mode. In self-boot mode, this pin is an open-collector output (I2C master).
The line connected to this pin should have a 2.2 kΩ pull-up resistor.
CCLK: SPI Clock. This pin can either run continuously or be gated off in
between SPI transactions.
Multipurpose GPIO, Serial Output Port Data 3 (SDATA_OUT3), or Auxiliary
ADC Input 0.
Multipurpose GPIO, Serial Output Port Data 2 (SDATA_OUT2), or Auxiliary
ADC Input 3.
Multipurpose GPIO, Serial Input Port Data 3 (SDATA_IN3), or Auxiliary
ADC Input 2.
Multipurpose GPIO, Serial Input Port Data 2 (SDATA_IN2), or Auxiliary
ADC Input 1.
Reserved. Tie to ground, either directly or through a pull-down resistor.
Crystal Oscillator Circuit Output. A 100 Ω damping resistor should be
connected between this pin and the crystal. This output should not be used
to directly drive a clock to another IC. If the crystal oscillator is not used, this
pin can be left disconnected.
Master Clock Input. MCLKI can either be connected to a 3.3 V clock signal or
can be the input from the crystal oscillator circuit.
PLL Ground Pin. The AGND, DGND, and PGND pins can be tied directly
together in a common ground plane. PGND should be decoupled to PVDD
with a 100 nF capacitor.
3.3 V Power Supply for the PLL and the Auxiliary ADC Analog Section. This
should be decoupled to PGND with a 100 nF capacitor.
PLL Loop Filter Connection. Two capacitors and a resistor need to be connected
to this pin, as shown in the Setting Master Clock/PLL Mode section.
3.3 V Analog Supply. This should be decoupled to AGND with a 100 nF capacitor.
PLL Mode Setting. PLL_MODE0 and PLL_MODE1 set the output frequency
Rev. 0 | Page 11 of 52
ADAU1702
Pin No.
39
Mnemonic
PLL_MODE1
Type 1
D_IN
40
CM
A_OUT
41
FILTD
A_OUT
43
44
45
46
47
VOUT3
VOUT2
VOUT1
VOUT0
FILTA
A_OUT
A_OUT
A_OUT
A_OUT
A_OUT
Page No.
17
20
20
20
20
Description
of the master clock PLL. See the Setting Master Clock/PLL Mode section for
more details.
1.5 V Common-Mode Reference. A 47 μF decoupling capacitor should be
connected between this pin and ground to reduce crosstalk between the
ADCs and DACs. The material of the capacitors is not critical. This pin can be
used to bias external analog circuits, as long as they are not drawing current
from CM (for example, the noninverting input of an op amp).
DAC Filter Decoupling Pin. Should be connected to a 10 μF capacitor to ground.
The capacitor material is not critical. The voltage on the FILTD is 1.5 V.
VOUT0 to VOUT3 are the DAC Outputs. Full-scale output voltage is 0.9 Vrms. These
outputs can be used with either active or passive output reconstruction filters.
ADC Filter Decoupling Pin. Should be connected to a 10 μF capacitor to ground.
The capacitor material is not critical. The voltage on the FILTA pin is 1.5 V.
1
PWR = power/ground, A_IN = analog input, D_IN = digital input, A_OUT = analog output, D_IO = digital input/output, D_IO/A_IO = digital input/output or analog
input/output.
Rev. 0 | Page 12 of 52
ADAU1702
TYPICAL PERFORMANCE CHARACTERISTICS
0.10
0.20
fS = 48kHz
0.15
fS = 48kHz
0.08
0.06
0.10
0.04
0.02
(dB)
(dB)
0.05
0
0
–0.02
–0.05
–0.04
–0.10
05798-031
–0.2
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
05798-033
–0.06
–0.15
–0.08
–0.10
2.2
0
0.5
1.0
10
10
–10
–20
–20
–30
–30
–40
–40
(dB)
–10
–50
–50
–60
–70
–70
–80
–80
05798-032
–60
–90
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
fS = 48kHz
0
fS = 48kHz
4.5
05798-034
0
(dB)
2.0
Figure 10. DAC Pass-Band Filter Response, fS = 48 kHz
Figure 8. ADC Pass-Band Filter Response, fS = 48 kHz
–100
1.5
FREQUENCY (kHz)
FREQUENCY (kHz)
–90
–100
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
FREQUENCY (kHz)
FREQUENCY (kHz)
Figure 9. ADC Stop-Band Filter Response, fS = 48 kHz
Figure 11. DAC Stop-Band Filter Response, fS = 48 kHz
Rev. 0 | Page 13 of 52
2.0
ADAU1702
SYSTEM BLOCK DIAGRAM
+3.3V
100nF
100nF
3.3V TO 1.8V
REGULATOR
CIRCUIT
100nF
100nF
10µF
+
10µF
+
IOVDD
PVDD
AVDD
DVDD
VDRIVE
18kΩ
ADC0
AUDIO ADC
INPUT SIGNALS
18kΩ
18kΩ
VOUT0
ADC1
VOUT1
DAC OUTPUT FILTERS
(ACTIVEORPASSIVE)
ADC_RES
VOUT2
FILTA
10µF
VOUT3
100nF
FILTD
ADCS
10µF
MP0
MULTIPURPOSE
PIN INTERFACES
+
100nF
MP1
ADAU1702
MP2
DACS
MP3
CM
MP4
10µF
MP5
+
100nF
MP6
MP7
MP8
MP9
MP10
ADDR0
MP11
ADDR1/CDATA/WB
CLATCH/WP
+3.3V
SDA/COUT
475Ω
3.3nF
56nF
SCL/CCLK
PLL_LF
PLL_MODE0
PLL
SETTINGS
EEPROM,
MICROCONTROLLER,
AND/OR SELFBOOT
LOGIC
SELFBOOT
PLL_MODE1
MCLKI
RESET
RESET LOGIC
3 TO 25MHz
22pF
100Ω
OSCO
AGND
DGND
PGND
05798-003
22pF
RSVD
Figure 12. System Block Diagram
Rev. 0 | Page 14 of 52
ADAU1702
OVERVIEW
The core of the ADAU1702 is a 28-bit DSP (56-bit with doubleprecision processing) optimized for audio processing. The
program and parameter RAMs can be loaded with a custom
audio processing signal flow built by using SigmaStudio graphical
programming software from Analog Devices, Inc. The values
stored in the parameter RAM control individual signal processing
blocks, such as equalization filters, dynamics processors, audio
delays, and mixer levels. A safeload feature allows for transparent
parameter updates and prevents clicks in the output signals.
The program RAM, parameter RAM, and register contents can
be saved in an external EEPROM, from which the ADAU1702
can self-boot on start-up. In this standalone mode, parameters
can be controlled through the on-board multipurpose pins. The
ADAU1702 can accept controls from switches, potentiometers,
rotary encoders, and IR receivers. Parameters such as volume
and tone settings can be saved to the EEPROM on power-down
and recalled again on power-up.
The ADAU1702 can operate with digital or analog inputs and
outputs, or a mix of both. The stereo ADC and four DACs each
have an SNR of at least +100 dB and a THD + N of at least
−83 dB. The 8-channel, flexible serial data input/output ports
allow glueless interconnection to a variety of ADCs, DACs,
general-purpose DSPs, S/PDIF receivers and transmitters, and
sample rate converters. The serial ports of the ADAU1702 can
be configured in I2S, left-justified, right-justified, or TDM serial
port compatible modes.
Twelve multipurpose (MP) pins allow the ADAU1702 to input
external control signals and output flags or controls to other
devices in the system. The MP pins can be configured as digital
I/Os, inputs to the 4-channel auxiliary ADC, or set up as the
serial data I/O ports. As inputs, they can be connected to buttons,
switches, rotary encoders, potentiometers, IR receivers, or other
external circuitry to control the internal signal processing program.
When configured as outputs, these pins can be used to drive
LEDs, control other ICs, or connect to other external circuitry
in an application.
The ADAU1702 has a sophisticated control port that supports
complete read/write capability of all memory locations. Control
registers are provided to offer complete control of the chip’s
configuration and serial modes. The ADAU1702 can be
configured for either SPI or I2C control, or can self-boot from
an external EEPROM.
An on-board oscillator can be connected to an external crystal
to generate the master clock. In addition, a master clock phaselocked loop (PLL) allows the ADAU1702 to be clocked from a
variety of different clock speeds. The PLL can accept inputs of
64 × fS, 256 × fS, 384 × fS, or 512 × fS to generate the internal
master clock of the core.
The SigmaStudio software is used to program and control the
SigmaDSP through the control port. Along with designing and
tuning a signal flow, the tools can be used to configure all of the
DSP registers and burn a new program into the external EEPROM.
SigmaStudio’s graphical interface allows anyone with digital or
analog audio processing knowledge to easily design a DSP
signal flow and port it to a target application. At the same time,
it provides enough flexibility and programmability for an
experienced DSP programmer to have in-depth control of the
design. In SigmaStudio, the user can connect graphical blocks
(such as biquad filters, dynamics processors, mixers, and
delays), compile the design, and load the program and
parameter files into the ADAU1702 memory through the
control port. Signal processing blocks available in the provided
libraries include
•
•
•
•
•
•
•
•
•
•
•
•
•
Single- and double-precision biquad filters
Processors with peak or rms detection for monochannel
and multichannel dynamics
Mixers and splitters
Tone and noise generators
Fixed and variable gain
Loudness
Delay
Stereo enhancement
Dynamic bass boost
Noise and tone sources
FIR filters
Level detectors
GPIO control and conditioning
Additional processing blocks are always being developed.
Analog Devices also provides proprietary and third-party
algorithms for applications such as matrix decoding, bass
enhancement, and surround virtualizers. Contact Analog
Devices for information about licensing these algorithms.
The ADAU1702 operates from a 1.8 V digital power supply
and a 3.3 V analog supply. An on-board voltage regulator can
be used to operate the chip from a single 3.3 V supply. It is
fabricated on a single monolithic, integrated circuit and is
packaged in a 48-lead LQFP for operation over the 0°C to
+70°C temperature range.
Rev. 0 | Page 15 of 52
ADAU1702
INITIALIZATION
This section details the procedure for properly setting up the
ADAU1702. The following five-step sequence provides an
overview of how to initialize the IC:
1.
2.
3.
4.
5.
Apply power to ADAU1702.
Wait for PLL to lock.
Load SigmaDSP program and parameters.
Set up registers (including multipurpose pins and digital
interfaces).
Turn off the default muting of the converters, clear the
data registers, and initialize the DAC setup register (see
the Control Registers Setup section for specific settings).
To only test analog audio pass-through (ADCs to DACs), Steps 3
and 4 can be skipped and the default internal program can be used.
POWER-UP SEQUENCE
The ADAU1702 has a built-in power-up sequence that
initializes the contents of all internal RAMs on power-up or
when the device is brought out of a reset. On the positive edge
of RESET, the contents of the internal program boot ROM are
copied to the internal program RAM memory, the parameter
RAM is filled with values (all 0s) from its associated boot ROM,
and all registers are initialized to 0s. The default boot ROM
program copies audio from the inputs to outputs without
processing it (see Figure 13). In this program, serial digital
Input 0 and Input 1 are output on DAC0 and DAC1 and serial
digital Output 0 and Output 1. ADC0 and ADC1 are output on
DAC2 and DAC3. The data memories are also zeroed at powerup. New values should not be written to the control port until
the initialization is complete.
PLL_MODE1 pins. The reset is synchronized to the falling edge
of the internal clock.
Table 11 lists typical times to boot the ADAU1702 into an
application’s operational state, assuming a 400 kHz I2C clock
loading a full program, parameter set, and all registers (about
6.5 kB). In reality, most applications will not fill the RAMs and
therefore boot time (Column 3 of Table 11) will be less.
CONTROL REGISTERS SETUP
The following registers must be set as described in this section
to initialize the ADAU1702. These settings are the basic
minimum settings needed to operate the IC with an analog
input/output of 48 kHz. More registers may need to be set,
depending on the application. See the RAMs and Registers
section for additional settings.
DSP Core Control Register (Address 2076)
Set Bits [4:2] (ADM, DAM, and CR) each to 1.
DAC Setup Register (Address 2087)
Set Bits [0:1] (DS [1:0]) to 01.
RECOMMENDED PROGRAM/PARAMETER
LOADING PROCEDURE
When writing large amounts of data to the program or parameter
RAM in direct write mode, the processor core should be disabled
to prevent unpleasant noises from appearing at the audio output.
1.
2.
Table 11. Power-Up Time
MCLKI Input
3.072 MHz (64 × fS)
11.289 MHz (256 × fS)
12.288 MHz (256 × fS)
18.432 MHz (384 × fS)
24.576 MHz (512 × fS)
Max Program/
Parameter/Register
Boot Time (I2C)
133 ms
133 ms
133 ms
133 ms
133 ms
Init.
Time
85 ms
23 ms
21 ms
16 ms
11 ms
Total
218 ms
156 ms
154 ms
149 ms
144 ms
3.
4.
5.
Set Bit 3 and Bit 4 (active low) of the core control register
to 1 to mute the ADCs and DACs. This begins a volume
ramp-down.
Set Bit 2 (active low) of the core control register to 1. This
zeroes the SigmaDSP accumulators, the data output registers,
and the data input registers.
Fill the program RAM using burst mode writes.
Fill the parameter RAM using burst mode writes.
Deassert Bit 2 to Bit 4 of the core control register.
DAC0
SDATA_OUT0
SDATA_IN0
DAC1
The PLL start-up time lasts for 2 cycles of the clock on the
MCLKI pin. This time ranges from 10.7 ms for a 24.576 MHz
(512 × fS) input clock to 85.3 ms for a 3.072 MHz (64 × fS) input
clock. This start-up time is measured from the rising edge of
RESET. Following the PLL startup, the duration of the ADAU1702
boot cycle is about 42 μs for a fS of 48 kHz. The user should
avoid writing to or reading from the ADAU1702 during this
start-up time. For an MCLK input of 12.288 MHz, the full
initialization sequence (PLL startup plus boot cycle) is
approximately 21 ms. As the device comes out of a reset,
the clock mode is immediately set by the PLL_MODE0 and
ADC0
DAC2
ADC1
DAC3
05798-004
18
Figure 13. Default Program Signal Flow
POWER-REDUCTION MODES
Sections of the ADAU1702 chip can be turned on and off as
needed to reduce power consumption. These include the ADCs,
DACs, and voltage reference.
The individual analog sections can be turned off by writing to
the auxiliary ADC and power control register. By default, the
ADCs, DACs, and reference are enabled (all bits set to 0). Each
Rev. 0 | Page 16 of 52
ADAU1702
of these can be turned off by writing a 1 to the appropriate bits
in this register. The ADC power-down mode powers down both
ADCs, and each DAC can be powered down individually. The
current savings is about 15 mA when the ADCs are powered
down and about 4 mA for each DAC that is powered down. The
voltage reference, which is supplied to both the ADCs and
DACs, should only be powered down if all ADCs and DACs are
powered down. The reference is powered down by setting both
Bit 6 and Bit 7 of the control register.
USING THE OSCILLATOR
The ADAU1702 can use an on-board oscillator to generate its
master clock. The oscillator is designed to work with a 256 × fS
master clock, which is 12.288 MHz for a fS of 48 kHz and
11.2896 MHz for a fS of 44.1 kHz. The crystal in the oscillator
circuit should be an AT-cut, parallel resonator operating at its
fundamental frequency. Figure 14 shows the external circuit
recommended for proper operation.
ADAU1702
OSCO
C2
MCLKI
The MCLK input of the ADAU1702 feeds a PLL, which generates
the 25 MIPS SigmaDSP core clock. In normal operation, the
input to MCLK must be one of the following: 64 × fS, 256 × fS,
384 × fS, or 512 × fS, where fS is the input sampling rate. The
mode is set on PLL_MODE0 and PLL_MODE1 as described in
Table 12. If the ADAU1702 is set to receive double-rate signals
(by reducing the number of program steps per sample by a factor
of 2 using the core control register), the master clock frequencies
must be 32 × fS, 128 × fS, 192 × fS, or 256 × fS. If the ADAU1702
is set to receive quad-rate signals (by reducing the number of
program steps per sample by a factor of 4 using the core control
register), the master clock frequencies must be 16 × fS, 64 × fS,
96 × fS, or 128 × fS. On power-up, a clock signal must be present
on MCLK so that the ADAU1702 can complete its initialization
routine.
Table 12. PLL Modes
Figure 14. Crystal Oscillator Circuit
The 100 Ω damping resistor on OSCO gives the oscillator a
voltage swing of approximately 2.2 V. The crystal shunt capacitance should be 7 pF. Its load capacitance should be about 18 pF,
although the circuit supports values of up to 25 pF. The necessary
values of the C1 and C2 load capacitors can be calculated from
the crystal load capacitance as follows:
CL =
SETTING MASTER CLOCK/PLL MODE
C1 × C2
+ C stray
C1 + C2
where Cstray is the stray capacitance in the circuit and is usually
assumed to be approximately 2 pF to 5 pF.
OSCO should not be used to directly drive the crystal signal to
another IC. This signal is an analog sine wave and is not
appropriate to drive a digital input. There are two options for
using the ADAU1702 to provide a master clock to other ICs in
the system. The first, and less recommended method, is to use a
high impedance input digital buffer on the OSCO signal. If this
is done, minimize the trace length to the buffer input. The
second method is to use a clock from the serial output port.
Pin MP11 can be set as an output (master) clock divided down
from the internal core clock. If this pin is set to serial output
port (OUTPUT_BCLK) mode in the multipurpose pin
configuration register (2081) and the port is set to master in
the serial output control register (2078), the desired output
frequency can also be set in the serial output control register
with Bits OBF [1:0] (see Table 49).
MCLKI Input
64 × fS
256 × fS
384 × fS
512 × fS
PLL_MODE0
0
0
1
1
PLL_MODE1
0
1
0
1
The clock mode should not be changed without also resetting
the ADAU1702. If the mode is changed during operation, a
click or pop can result in the output signals. The state of the
PLL_MODEx pins should be changed while RESET is held low.
The PLL loop filter should be connected to the PLL_LF pin. This
filter, shown in Figure 15, includes three passive components—
two capacitors and a resistor. The values of these components
do not need to be exact; the tolerance can be up to 10% for the
resistor and up to 20% for the capacitors. The 3.3 V signal shown in
Figure 15 can be connected to the AVDD supply of the chip.
Rev. 0 | Page 17 of 52
3.3V
475Ω
3.3nF
56nF
ADAU1702
PLL_LF
05798-006
100Ω
05798-005
C1
If the oscillator is not utilized in the design, it can be powered
down to save power. This can be done if a system master clock
is already available in the system. By default, the oscillator is
powered on. The oscillator powers down when a 1 is written to
the OPD bit of the oscillator power-down register (see Table 60).
Figure 15. PLL Loop Filter
ADAU1702
The digital voltage of the ADAU1702 must be set to 1.8 V. The
chip includes an on-board voltage regulator that allows the
device to be used in systems without an available 1.8 V supply
but with an available 3.3 V supply. The only external components
needed in such instances are a PNP transistor, a resistor, and a
few bypass capacitors. Only one pin, VDRIVE, is necessary to
support the regulator.
The recommended design for the voltage regulator is shown
in Figure 16. The 10 μF and 100 nF capacitors shown in this
configuration are recommended for bypassing, but are not
necessary for operation. Each DVDD pin should have its own
100 nF bypass capacitor, but only one bulk capacitor (10 μF to
47 μF) is needed for both DVDD pins. With this configuration,
3.3 V is the main system voltage; 1.8 V is generated at the
transistor’s collector, which is connected to the DVDD pins.
VDRIVE is connected to the base of the PNP transistor. If the
regulator is not used in the design, VDRIVE can be tied to
ground.
Two specifications must be considered when choosing a
regulator transistor: The transistor’s current amplification factor
(hFE or beta) should be at least 100, and the transistor’s collector
must be able to dissipate the heat generated when regulating
from 3.3 V to 1.8 V. The maximum digital current drawn from
the ADAU1702 is 60 mA. The equation to determine the
minimum power dissipation of the transistor is as follows:
(3.3 V − 1.8 V) × 60 mA = 90 mW
There are many transistors, such as the FZT953 from Zetex
Semiconductors, with these specifications available in small
SOT-23 or SOT-223 packages.
3.3V
10µF
+
1kΩ
100nF
ADAU1702
DVDD
VDRIVE
05798-007
VOLTAGE REGULATOR
Figure 16. Voltage Regulator Configuration
Rev. 0 | Page 18 of 52
ADAU1702
AUDIO ADCS
The stereo audio ADCs are current input; therefore, a voltageto-current resistor is required on the inputs. This means that
the voltage level of the input signals to the system can be set to
any level; only the input resistors need to be scaled to provide
the proper full-scale current input. The ADC0 and ADC1 input
pins, as well as ADC_RES, have an internal 2 kΩ resistor for
ESD protection. The voltage seen directly on the ADC input
pins is the 1.5 V common mode.
The external resistor connected to ADC_RES sets the full-scale
current input of the ADCs. The full range of the ADC inputs is
100 μArms with an external 18 kΩ resistor on ADC_RES (20 kΩ
total, because it is in series with the internal 2 kΩ). The only
reason to change the ADC_RES resistor is if a sampling rate
other than 48 kHz is used.
The voltage-to-current resistors connected to ADC0/ADC1 set
the full-scale voltage input of the ADCs. With a full-scale current
input of 100 μArms, a 2.0 Vrms signal with an external 18 kΩ resistor
(in series with the 2 kΩ internal resistor) results in an input using
the full range of the ADC. The matching of these resistors to the
ADC_RES resistor is important to the operation of the ADCs.
For these three resistors, a 1% tolerance is recommended.
The values of the resistors (internal plus external) in series with
the ADC0 and ADC1 pins can be calculated as follows:
R Input Total = (RMS Input Voltage) × 10 kΩ ×
Table 13 lists the external and total resistor values for common
signal input levels at a 48 kHz sampling rate. A full-scale rms
input voltage of 0.9 V is shown in the table because a full-scale
signal at this input level is equal to a full-scale output on the DACs.
Table 13. ADC Input Resistor Values
Full-Scale
RMS Input
Voltage (V)
0.9
1.0
2.0
ADC_RES
Value (kΩ)
18
18
18
ADC0/ADC1
Resistor
Value (kΩ)
7
8
18
Total ADC0/ADC1
Input Resistance
(External +
Internal) (kΩ)
9
10
20
Figure 17 shows a typical configuration of the ADC inputs for
a 2.0 Vrms input signal for a fS of 48 kHz. The 47 μF capacitors are
used to ac-couple the signals so that the inputs are biased at 1.5 V.
Either the ADC0 and/or ADC1 input pins can be left
unconnected if that channel of the ADC is unused.
ADAU1702
47µF
48,000
f S _ NEW
Rev. 0 | Page 19 of 52
18kΩ
ADC0
47µF
These calculations of resistor values assume a 48 kHz sample
rate. The recommended input and current setting resistors
scale linearly with the sample rate because the ADCs have a
switched-capacitor input. The total value (2 kΩ internal plus
external resistor) of the ADC_RES resistor with sample rate
fS_NEW can be calculated as follows:
Rtotal = 20 kΩ ×
48,000
f S _ NEW
18kΩ
ADC1
18kΩ
ADC_RES
05798-008
The ADAU1702 has two Σ-Δ ADCs. The signal-to-noise ratio
(SNR) of the ADCs is 100 dB and the THD + N is −83 dB.
Figure 17. Audio ADC Input Configuration
ADAU1702
AUDIO DACS
To properly initialize the DACs, Bits DS [1:0] in the DAC setup
register (Address 2087) should be set to 01.
47µF
DAC_OUT
The DAC outputs can be filtered with either an active or a
passive reconstruction filter. A single-pole, passive low-pass
filter with a 50 kHz corner frequency, as shown in Figure 18, is
sufficient to filter the DAC out-of-band noise, although an
active filter may provide better audio performance. Figure 19
560Ω
FILTER_OUT
5.6nF
Figure 18. Passive DAC Output Filter
+
C8
470µF
47µF
150pF
604Ω
AD8606
3.3nF
FILTER_OUT
Figure 19. Active DAC Output Filter
Rev. 0 | Page 20 of 52
49.9kΩ
05798-011
4.75kΩ 4.75kΩ
+
DAC_OUT
05798-009
The DACs are in an inverting configuration. If a signal inversion
from input to output is undesirable, it can be reversed by using
either an inverting configuration for the output filter or by simply
inverting the signal in the SigmaDSP program flow.
shows a triple-pole, active, low-pass filter that provides a steeper
roll-off and better stop-band attenuation than the passive filter.
In this configuration, the V+ and V− pins of the AD8606 op
amp are set to VDD and ground, respectively.
+
The ADAU1702 includes four Σ-Δ DACs. The SNR of the DAC
is 104 dB and the THD + N is −90 dB. A full-scale output on the
DACs is 0.9 Vrms (2.5 Vp-p).
ADAU1702
CONTROL PORTS
The ADAU1702 can operate in one of three control modes:
•
•
•
I2C control
SPI control
Self-boot (no external controller)
The ADAU1702 has both a 4-wire SPI control port and a
2-wire I2C bus control port. Each can be used to set the RAMs
and registers. When the SELFBOOT pin is low at power-up, the
part defaults to I2C mode but can be put into SPI control mode
by pulling the CLATCH/WP pin low three times. When the
SELFBOOT pin is set high at power-up, the ADAU1702 loads
its program, parameters, and register settings from an external
EEPROM on startup.
The control port is capable of full read/write operation for all
addressable memory and registers. Most signal processing
parameters are controlled by writing new values to the parameter RAM using the control port. Other functions, such as mute
and input/output mode control, are programmed by writing to
the registers.
All addresses may be accessed in both a single-address mode or
a burst mode. The first byte (Byte 0) of a control port write
contains the 7-bit chip address plus the R/W bit. The next two
bytes (Byte 1 and Byte 2) together form the subaddress of the
memory or register location within the ADAU1702. This
subaddress must be two bytes because the memory locations
within the ADAU1702 are directly addressable and their sizes
exceed the range of single-byte addressing. All subsequent bytes
(starting with Byte 3) contain the data, such as control port data,
program data, or parameter data. The number of bytes per word
depends on the type of data that is being written. The exact formats
for specific types of writes are shown in Table 22 to Table 31.
The ADAU1702 has several mechanisms for updating signal
processing parameters in real time without causing pops or
clicks. If large blocks of data need to be downloaded, the output
of the DSP core can be halted (using the CR bit in the DSP core
control register (Address 2076)), new data can be loaded, and
then the device can be restarted. This is typically done during
the booting sequence at start-up or when loading a new program
into RAM. In cases where only a few parameters need to be
changed, they can be loaded without halting the program. To
avoid unwanted side effects while loading parameters on the fly, the
SigmaDSP provides the safeload registers. The safeload registers
can be used to buffer a full set of parameters (for example, the
five coefficients of a biquad) and then transfer these parameters
into the active program within one audio frame. The safeload
mode uses internal logic to prevent contention between the
DSP core and the control port.
The control port pins are multifunctional, depending on the
mode in which the part is operating. Table 14 details these
multiple functions.
Table 14. Control Port Pins and SELFBOOT Pin Functions
Pin
SCL/CCLK
SDA/COUT
ADDR1/CDATA/WB
CLATCH/WP
ADDR0
I2C Mode
SCL—input
SDA—open-collector output
ADDR1—input
Unused input—tie to ground or VDD
ADDR0—input
SPI Mode
CCLK—input
COUT—output
CDATA—input
CLATCH—input
ADDR0—input
Rev. 0 | Page 21 of 52
Self-Boot
SCL—output
SDA—open-collector output
WB—writeback trigger
WP—EEPROM write protect, open-collector output
Unused input—tie to ground or VDD
ADAU1702
I2C PORT
Addressing
2
The ADAU1702 supports a 2-wire serial (I C-compatible)
microprocessor bus driving multiple peripherals. Two pins,
serial data (SDA) and serial clock (SCL), carry information
between the ADAU1702 and the system I2C master controller.
In I2C mode, the ADAU1702 is always a slave on the bus,
meaning it cannot initiate a data transfer. Each slave device is
recognized by a unique address. The address byte format is
shown in Table 15. The ADAU1702 slave addresses are set with
the ADDR0 and ADDR1 pins. The address resides in the first
seven bits of the I2C write. The LSB of this byte sets either a read
or write operation. Logic Level 1 corresponds to a read operation,
and Logic Level 0 corresponds to a write operation. Bit 5 and
Bit 6 of the address are set by tying the ADDRx pins of the
ADAU1702 to Logic Level 0 or Logic Level 1. The full byte
addresses, including the pin settings and read/write bit, are
shown in Table 16.
Burst mode addressing, where the subaddresses are automatically incremented at word boundaries, can be used for writing
large amounts of data to contiguous memory locations. This
increment happens automatically after a single-word write unless a
stop condition is encountered. The registers and RAMs in the
ADAU1702 range in width from one to five bytes, so the autoincrement feature knows the mapping between subaddresses and
the word length of the destination register (or memory location). A
data transfer is always terminated by a stop condition.
Both SDA and SCL should have 2.2 kΩ pull-up resistors on the
lines connected to them. The voltage on these signal lines should
not be more than IOVDD (3.3 V).
Table 15. ADAU1702 I2C Address Byte Format
Bit 0
0
Bit 1
1
Bit 2
1
Bit 3
0
Bit 4
1
Bit 5
ADDR1
Bit 6
ADDR0
Table 16. ADAU1702 I2C Addresses
ADDR1
0
0
0
0
1
1
1
1
ADDR0
0
0
1
1
0
0
1
1
Read/Write
0
1
0
1
0
1
0
1
Slave Address
0x68
0x69
0x6A
0x6B
0x6C
0x6D
0x6E
0x6F
Bit 7
R/W
Initially, each device on the I2C bus is in an idle state and
monitoring the SDA and SCL lines for a start condition and
the proper address. The I2C master initiates a data transfer by
establishing a start condition, defined by a high-to-low transition
on SDA while SCL remains high. This indicates that an address/
data stream follows. All devices on the bus respond to the start
condition and shift the next eight bits (the 7-bit address plus the
R/W bit) MSB first. The device that recognizes the transmitted
address responds by pulling the data line low during the ninth
clock pulse. This ninth bit is known as an acknowledge bit. All
other devices withdraw from the bus at this point and return to
the idle condition. The R/W bit determines the direction of the
data. A Logic 0 on the LSB of the first byte means the master
will write information to the peripheral, whereas a Logic 1
means the master will read information from the peripheral
after writing the subaddress and repeating the start address. A
data transfer takes place until a stop condition is encountered.
A stop condition occurs when SDA transitions from low to high
while SCL is held high. Figure 20 shows the timing of an I2C
write, and Figure 21 shows an I2C read.
Stop and start conditions can be detected at any stage during the
data transfer. If these conditions are asserted out of sequence with
normal read and write operations, the ADAU1702 immediately
jumps to the idle condition. During a given SCL high period,
the user should only issue one start condition, one stop condition,
or a single stop condition followed by a single start condition. If
an invalid subaddress is issued by the user, the ADAU1702 does
not issue an acknowledge and returns to the idle condition. If
the user exceeds the highest subaddress while in auto-increment
mode, one of two actions is taken. In read mode, the ADAU1702
outputs the highest subaddress register contents until the master
device issues a no acknowledge, indicating the end of a read. A
no-acknowledge condition is where the SDA line is not pulled
low on the ninth clock pulse on SCL. If the highest subaddress
location is reached while in write mode, the data for the invalid
byte is not loaded into any subaddress register, a no acknowledge
is issued by the ADAU1702, and the part returns to the idle
condition.
Rev. 0 | Page 22 of 52
ADAU1702
SCK
SDA
START BY
MASTER
0
0
0
0
0
0
ADR
SEL
R/W
ACK. BY
ADAU1702
ACK .BY
ADAU1702
FRAME 1
CHIP ADDRESS BYTE
FRAME 2
SUBADDRESS BYTE 1
SCK
(CONTINUED)
ACK. BY
ADAU1702
FRAME 2
SUBADDRESS BYTE 2
FRAME 3
DATA BYTE 1
ACK. BY
ADAU1702
STOP BY
MASTER
05798-012
SDA
(CONTINUED)
Figure 20. I2C Write to ADAU1702 Clocking
SCK
ADR
SEL
SDA
R/W
ACK. BY
ADAU1702
ACK BY
ADAU1702
START BY
MASTER
FRAME 1
CHIP ADDRESS BYTE
FRAME 2
SUBADDRESS BYTE 1
SCK
(CONTINUED)
SDA
(CONTINUED)
ADR
SEL
FRAME 3
SUBADDRESS BYTE 2
ACK BY
ADAU1702
REPEATED
START BY MASTER
R/W
ACK. BY
ADAU1702
FRAME 4
CHIP ADDRESS BYTE
SCK
(CONTINUED)
ACK BY
MASTER
FRAME 5
READ DATA BYTE 1
ACK. BY
MASTER
FRAME 6
READ DATA BYTE 2
Figure 21. I2C Read from ADAU1702 Clocking
Rev. 0 | Page 23 of 52
STOP BY
MASTER
05798-013
SDA
(CONTINUED)
ADAU1702
I2C Read and Write Operations
data back to the master. The master then responds every ninth
pulse with an acknowledge pulse to the ADAU1702.
Figure 22 shows the timing of a single-word write operation.
Every ninth clock, the ADAU1702 issues an acknowledge by
pulling SDA low.
Figure 25 shows the timing of a burst mode read sequence. This
figure shows an example where the target read registers are two
bytes. The ADAU1702 increments its subaddress every two bytes
because the requested subaddress corresponds to a register or
memory area with word lengths of two bytes. Other address
ranges may have a variety of word lengths ranging from one to
five bytes. The ADAU1702 always decodes the subaddress and
sets the auto-increment circuit so that the address increments
after the appropriate number of bytes.
Figure 23 shows the timing of a burst mode write sequence.
This figure shows an example where the target destination
registers are two bytes. The ADAU1702 knows to increment its
subaddress register every two bytes because the requested
subaddress corresponds to a register or memory area with a
2-byte word length.
The timing of a single-word read operation is shown in Figure 24.
Note that the first R/W bit is 0, indicating a write operation. This is
because the subaddress still needs to be written to set up the
internal address. After the ADAU1702 acknowledges the receipt
of the subaddress, the master must issue a repeated start command
followed by the chip address byte with the R/W set to 1 (read).
This causes the ADAU1702 SDA to reverse and begin driving
S
Chip address,
R/W = 0
AS
Subaddress high
AS
Figure 22 to Figure 25 use the following abbreviations:
S = start bit
P = stop bit
AM = acknowledge by master
AS = acknowledge by slave
Subaddress low
AS
Data Byte 1
AS
Data Byte 2
…
AS
Data Byte N
P
Figure 22. Single-Word I2C Write Format
S
Chip address,
R/W = 0
AS
Subaddress
high
AS
Subaddress
low
AS
DataWord 1,
Byte 1
AS
AS
DataWord 2,
Byte 1
Data
Byte 1
AM
DataWord 1,
Byte 2
AS
DataWord 2,
Byte 2
AS
…
P
Data
Byte N
P
Figure 23. Burst Mode I2C Write Format
S
Chip address,
R/W = 0
AS
Subaddress
high
AS
Subaddress
low
AS
S
Chip address,
R/W = 1
AS
Data
Byte 2
…
AM
Figure 24. Single-Word I2C Read Format
S
Chip address,
R/W = 0
AS
Subaddress
high
AS
Subaddress
low
AS
S
Chip address,
R/W = 1
Figure 25. Burst Mode I2C Read Format
Rev. 0 | Page 24 of 52
AS
DataWord 1,
Byte 1
AM
DataWord 1,
Byte 2
AM
…
P
ADAU1702
SPI PORT
Table 17. ADAU1702 SPI Address Byte Format
2
By default, the ADAU1702 is in I C mode, but can be put into SPI
control mode by pulling CLATCH/WP low three times. The SPI
port uses a 4-wire interface, consisting of CLATCH, CCLK,
CDATA, and COUT signals and is always a slave port. The
CLATCH signal should go low at the beginning of a transaction
and high at the end of a transaction. The CCLK signal latches
CDATA on a low-to-high transition. COUT data is shifted out of
the ADAU1702 on the falling edge of CCLK and should be
clocked into a receiving device, such as a microcontroller, on the
CCLK rising edge. The CDATA signal carries the serial input
data, and the COUT signal is the serial output data. The COUT
signal remains three-stated until a read operation is requested.
This allows other SPI-compatible peripherals to share the same
readback line. All SPI transactions have the same basic format
shown in Table 18. A timing diagram is shown in Figure 4. All
data should be written MSB first. The ADAU1702 cannot be
taken out of SPI mode without a full reset.
Bit 0
0
Bit 1
0
Bit 2
0
Bit 3
0
Bit 4
0
Bit 5
0
Bit 6
ADDR0
Subaddress
The 12-bit subaddress word is decoded into a location in one of
the memories or registers. This subaddress is the location of the
appropriate RAM location or register. The MSBs of the subaddress
are zero-padded to bring the word to a full 2-byte length.
Data Bytes
The number of data bytes varies according to the register or
memory being accessed. During a burst mode write, an initial
subaddress is written followed by a continuous sequence of data
for consecutive memory/register locations. The detailed data
format for continuous mode operation is shown in Table 23 and
Table 25 in the Read/Write Data Formats section.
A sample timing diagram for a single-write SPI operation to the
parameter RAM is shown in Figure 26. A sample timing diagram
of a single-read SPI operation is shown in Figure 27. The COUT
pin goes from three-state to being driven at the beginning of
Byte 3. In this example, Byte 0 to Byte 2 contain the addresses
and R/W bit and subsequent bytes carry the data.
Chip Address R/W
The first byte of an SPI transaction includes the 7-bit chip address
and a R/W bit. The chip address is set by the ADDR0 pin. This
allows two ADAU1702s to share a CLATCH signal, yet still operate
independently. When ADDR0 is low, the chip address is 0000000;
when it is high, the address is 0000001 (see Table 17). The LSB
of this first byte determines whether the SPI transaction is a
read (Logic Level 1) or a write (Logic Level 0).
Table 18. Generic Control Word Format
Byte 0
chip_adr [6:0], R/W
Byte 2
subadr [7:0]
Byte 4 1
data
Byte 3
data
Continues to end of data.
CLATCH
CDATA
BYTE 0
BYTE 1
BYTE 2
05798-014
CCLK
BYTE 3
Figure 26. SPI Write to ADAU1702 Clocking (Single-Write Mode)
CLATCH
CCLK
CDATA
COUT
BYTE 1
BYTE 0
HI-Z
DATA
DATA
Figure 27. SPI Read from ADAU1702 Clocking (Single-Read Mode)
Rev. 0 | Page 25 of 52
DATA
HI-Z
05798-015
1
Byte 1
0000, subadr [11:8]
Bit 7
R/W
ADAU1702
SELF-BOOT
EEPROM Format
On power-up, the ADAU1702 can load a program and a set
of parameters that have been saved in an external EEPROM.
Combined with the auxiliary ADC and the multipurpose pins,
this eliminates the need for a microcontroller in the system. The
self-booting is accomplished by the ADAU1702 acting as a master
on the I2C bus on start-up, which occurs when the SELFBOOT
pin is set high. The ADAU1702 cannot self-boot in SPI mode.
The EEPROM data contains a sequence of messages. Each
discrete message is one of the seven types defined in Table 19.
Each message consists of a sequence of one or more bytes. The
first byte identifies the message type. Bytes are written MSB
first. Most messages are block write (0x01) types, which are
used for writing to the ADAU1702 program RAM, parameter
RAM, and control registers.
The maximum necessary EEPROM size for program and
parameters is 6688 bytes, or just over 6.5 kB. This does not
include register settings or overhead bytes, but such factors do
not add a significant number of bytes. This much memory is
only needed if the program RAM (512 × five bytes), parameter
RAM (1024 × four bytes), and interface registers (8 × four
bytes) are completely full. An 8 kB EEPROM has sufficient
memory for this application.
The body of the message following the message type should
start with a 0x00 byte—this is the chip address. As with all
other control port transactions, following the chip address is
a 2-byte register/memory address field.
A self-boot operation is triggered on the rising edge of RESET
when the SELFBOOT and WP pins are set high. The ADAU1702
reads the program, parameters, and register settings from the
EEPROM. After the ADAU1702 finishes self-booting, additional
messages can be sent to the ADAU1702 on the I2C bus, although
this typically is not necessary in a self-booting application. The
I2C device address is 0x68 for a write and 0x69 for a read in this
mode. The ADDRx pins have different functions when the chip
is in this mode, so the settings on them are ignored.
The ADAU1702 does not self-boot if WP is set low. Holding
this pin low allows the EEPROM to be programmed in-circuit.
The WP pin is pulled low (it typically has a resistor pull-up) to
enable writes to the EEPROM, but this in turn disables the selfboot function until the WP pin is returned high.
The ADAU1702 is a master on the I2C bus during self-boot and
writeback. Although it is uncommon for an application using
self-boot to also have a microcontroller connected to the control
lines, care should be taken that no other device tries to write to the
I2C bus during self-boot or writeback. The ADAU1702 generates
SCL at 8 × fS; therefore, for a fS of 48 kHz, SCL runs at 384 kHz.
SCL has a duty cycle of 3/8 in accordance with the I2C specification.
The ADAU1702 reads from EEPROM Chip Address 0xA1. The
LSBs of the addresses of some EEPROMs are pin configurable;
in most cases, these pins should be tied low to set this address.
Table 20 shows an example of what should be stored in the
EEPROM, starting with EEPROM Address 0. In this example,
the interface registers are first set to control port write mode
(Line 1), which is followed by 18 no-operation (no-op) bytes
(Line 2 to Line 4) so that the interface register data appears on
Page 2 of the EEPROM. Next, follows the write header (Line 4)
and then 32 bytes of interface register data (Line 5 to Line 8).
Finally, the program RAM data, starting at ADAU1702 Address
0x04, 0x00 is written (Line 9 to Line 11). In this example, the
program length is 70 words, or 350 bytes, so 332 more bytes
are included in the EEPROM but are not shown in Table 20.
Writeback
A writeback occurs when the WB pin is triggered and data is
written to the EEPROM from the ADAU1702. This function is
typically used to save the volume setting and other parameter
settings to the EEPROM just before power is removed from the
system. A rising edge on the WB pin triggers a writeback when
the device is in self-boot mode, unless a message to set the WB
to the falling edge sensitive (0x05) is contained in the self-boot
message sequence. Only one writeback takes place unless a
message to set multiple writebacks (0x04) is contained in the
self-boot message sequence. The WP pin is pulled low when a
writeback is triggered to allow writing to the EEPROM.
The ADAU1702 is only capable of writing back the contents of
the interface registers to the EEPROM. These registers are usually
set by the DSP program, but can also be written to directly after
setting Bit 6 of the core control register. The parameter settings
that should be saved are configured in SigmaStudio.
Rev. 0 | Page 26 of 52
ADAU1702
The writeback function writes data from the ADAU1702
interface registers to the second page of the self-boot EEPROM,
Address 32 to Address 63. Starting at EEPROM Address 26
(so that the interface register data begins at Address 32), the
EEPROM should be programmed with six bytes—the message
byte (0x01), two length bytes, the chip address (0x00), and the
2-byte subaddress for the interface registers (0x08, 0x00). There
must be a message to the DSP core control register to enable
writing to the interface registers prior to the interface register
data in the EEPROM. This should be stored in EEPROM
Address 0. No-op messages (0x03) can be used in between
messages to ensure that these conditions are met.
The ADAU1702 writes to EEPROM Chip Address 0xA0. The
LSBs of the addresses of some EEPROMs are pin configurable; in
most cases, these pins should be tied low to set the address to 0xA0.
The maximum number of bytes that is written back from the
ADAU1702 is 35 (eight 4-byte interface registers plus three
bytes of EEPROM-addressing overhead). With SCL running at
384 kHz, the writeback operation takes approximately 73 μs to
complete after being triggered. Ensure that sufficient power is
available to the system to allow enough time for a writeback to
complete, especially if the WB signal is triggered from a falling
power supply voltage.
Table 19. EEPROM Message Types
Message ID
0x00
0x01
Message Type
End
Write
0x02
0x03
0x04
0x05
0x06
Delay
No operation executed
Set multiple writeback
Set WB to falling edge sensitive
End and wait for writeback
Following Bytes
None
Two bytes indicating message length followed by appropriate
number of data bytes
Two bytes for delay
None
None
None
None
Table 20. EEPROM Data Example
1
0x01
Write
0x00
0x05
0x00
Device addr.
2
0x03
0x03
0x03
0x03
0x03
No-op bytes
0x03
0x03
0x03
3
0x03
0x03
0x03
0x03
0x03
No-op bytes
0x03
0x03
0x03
4
0x03
0x03
No-op bytes
0x01
Write
0x00
Length
0x08
0x1C
Core control register address
0x23
Length
0x00
Device addr.
0x00
0x40
Core control register data
0x08
0x00
Interface register address
5
0x00
0x00
0x00
0x00
0x00
Interface register data
0x00
0x00
0x00
6
0x00
0x00
0x00
0x00
0x00
Interface register data
0x00
0x00
0x00
7
0x00
0x00
0x00
0x00
0x00
Interface register data
0x00
0x00
0x00
8
0x00
0x00
0x00
0x00
0x00
Interface register data
0x00
0x00
0x00
9
0x01
Write
0x01
10
0x00
0x00
0x01
11
0x00
0x00
0x00
0x61
Length
0x00
Device addr.
0x04
0x00
Program RAM address
0x00
0x00
Program RAM data
0x00
0x00
Program RAM data
0x00
0xE8
0x01
0x00
0x01
0x00
Program RAM data (continues for 332 more bytes)
0x08
0x00
Rev. 0 | Page 27 of 52
ADAU1702
SIGNAL PROCESSING
The ADAU1702 is designed to provide all audio signal processing
functions commonly used in stereo or multichannel playback
systems. The signal processing flow is designed using the
SigmaStudio software, which allows graphical entry and realtime control of all signal processing functions.
with a range of 1.0 (minus 1 LSB) to −1.0. Figure 28 shows the
maximum signal levels at each point in the data flow in both
binary and decibel levels.
Many of the signal processing functions are coded using full,
56-bit, double-precision arithmetic data. The input and output
word lengths of the DSP core are 24 bits. Four extra headroom
bits are used in the processor to allow internal gains of up to
24 dB without clipping. Additional gains can be achieved by
initially scaling down the input signal in the DSP signal flow.
DATA IN
NUMERIC FORMATS
DSP systems commonly use a standard numeric format.
Fractional number systems are specified by an A.B format,
where A is the number of bits to the left of the decimal point
and B is the number of bits to the right of the decimal point.
The ADAU1702 uses the same numeric format for both the
parameter and data values. The format is as follows.
Numerical Format: 5.23
4-BIT SIGN EXTENSION
SERIAL
PORT
1.23
(0dB)
SIGNAL
PROCESSING
(5.23 FORMAT)
5.23
(24dB)
DIGITAL
CLIPPER
5.23
(24dB)
05798-016
1.23
(0dB)
1.23
(0dB)
Figure 28. Numeric Precision and Clipping Structure
PROGRAMMING
On power-up, the ADAU1702 default program passes the
unprocessed input signals to the outputs (shown in Figure 13),
but the outputs are muted by default (see the Power-Up Sequence
section). There are 512 instruction cycles per audio sample,
resulting in about 25 MIPS available. The SigmaDSP runs in a
stream-oriented manner, meaning that all 512 instructions are
executed each sample period. The ADAU1702 can also be set
up to accept double- or quad-speed inputs by reducing the
number of instructions per sample that are set in the core
control register.
The part can be programmed easily using SigmaStudio (Figure 29),
a graphical tool provided by Analog Devices. No knowledge of
writing line-level DSP code is required. More information about
SigmaStudio can be found at www.analog.com.
Linear range: −16.0 to (+16.0 − 1 LSB)
Examples:
1000 0000 0000 0000 0000 0000 0000 = −16.0
1110 0000 0000 0000 0000 0000 0000 = −4.0
1111 1000 0000 0000 0000 0000 0000 = −1.0
1111 1110 0000 0000 0000 0000 0000 = −0.25
1111 1111 0011 0011 0011 0011 0011 = −0.1
1111 1111 1111 1111 1111 1111 1111 = (1 LSB below 0.0)
0000 0000 0000 0000 0000 0000 0000 = 0.0
0000 0000 1100 1100 1100 1100 1101 = 0.1
0000 0010 0000 0000 0000 0000 0000 = 0.25
0000 1000 0000 0000 0000 0000 0000 = 1.0
0010 0000 0000 0000 0000 0000 0000 = 4.0
0111 1111 1111 1111 1111 1111 1111 = (16.0 − 1 LSB).
A digital clipper circuit is used between the output of the DSP
core and the DACs or serial port outputs (see Figure 28). This
clips the top four bits of the signal to produce a 24-bit output
Rev. 0 | Page 28 of 52
05978-035
The serial port accepts up to 24 bits on the input and is signextended to the full 28 bits of the DSP core. This allows internal
gains of up to 24 dB without internal clipping.
Figure 29. SigmaStudio Screen Shot
ADAU1702
RAMS AND REGISTERS
Table 21. RAM Map and Read/Write Modes
Memory
Parameter RAM
Program RAM
Reserved
1
2
Size
1024 × 32
512 × 40
N/A
Address Range
0 to 1023 (0x0000 to 0x03FF)
1024 to 1535 (0x0400 to 0x05FF)
1536 to 2047 (0x0600 to 0x07FF) 2
Read
Yes
Yes
No
Write
Yes
Yes
No
Write Modes
Direct write 1 safeload write
Direct write1
N/A
Internal registers should be cleared first to avoid clicks/pops.
Addresses 1536 to 2047 (0x0600 to 0x07FF) are reserved RAM locations and data can not be written to them.
ADDRESS MAPS
Table 21 shows the RAM map and Table 32 shows the ADAU1702
register map. The address space encompasses a set of registers
and two RAMs: one holds signal processing parameters and one
holds the program instructions. The program RAM and parameter
RAM are initialized on power-up from on-board boot ROMs
(see the Power-Up Sequence section).
All RAMs and registers have a default value of all 0s, except for
the program RAM, which is loaded with the default program
(see the Initialization section).
PARAMETER RAM
The parameter RAM is 32 bits wide and occupies Address 0
to Address 1023. Each parameter is padded with four 0s before
the MSB to extend the 28-bit word to a full 4-byte width. The
parameter RAM is initialized to all 0s on power-up. The data
format of the parameter RAM is twos complement, 5.23.
This means that the coefficients can range from +16.0 (minus
1 LSB) to −16.0, with 1.0 represented by the binary word
0000 1000 0000 0000 0000 0000 0000 or by the hexadecimal
word 0x00 0x80 0x00 0x00.
The parameter RAM can be written using one of the two
following methods: a direct read/write or a safeload write.
Direct Read/Write
This method allows direct access to the program RAM and
parameter RAM. This mode of operation is typically used
during a complete new loading of the RAM using burst mode
addressing. The clear registers bit in the core control register
should be set to 0 using this mode to avoid any clicks or pops in
the outputs. Note that this mode can be used during live program
execution, but because there is no handshaking between the
core and the control port, the parameter RAM is unavailable to
the DSP core during control writes, resulting in clicks and pops
in the audio stream.
Safeload Write
Up to five safeload registers can be loaded with the parameter
RAM address/data. The data is then transferred to the requested
address when the RAM is not busy. This method can be used
for dynamic updates while live program material is playing
through the ADAU1702. For example, a complete update of one
biquad section can occur in one audio frame while the RAM is
not busy. This method is not available for writing to the
program RAM or control registers.
DATA RAM
The ADAU1702 data RAM is used to store audio data words for
processing. For the most part, this process is transparent to the
user. The user cannot directly address this RAM space, which
has a size of 0.5k words, from the control port.
Data RAM utilization should be considered when implementing
blocks that require large amounts of data RAM space, such as
delays. The SigmaDSP core processes delay times in one-sample
increments; therefore, the total pool of delay available to the user
equals 512 multiplied by the sample period. For a fS of 48 kHz,
the pool of available delay is a maximum of about 11 ms. In
practice, this much data memory is not available to the user
because every block in a design uses a few data memory locations
for its processing. In most DSP programs, this does not significantly impact the total delay time. The SigmaStudio compiler
manages the data RAM and indicates if the number of addresses
needed in the design exceeds the maximum available.
READ/WRITE DATA FORMATS
The read/write formats of the control port are designed to
be byte oriented. This allows easy programming of common
microcontroller chips. To fit into a byte-oriented format, 0s are
appended to the data fields before the MSB to extend the dataword to eight bits. For example, 28-bit words written to the
parameter RAM are appended with four leading 0s to equal
32 bits (4 bytes); 40-bit words written to the program RAM are
not appended with 0s because they are already a full five bytes.
These zero-padded data fields are appended to a 3-byte field
consisting of a 7-bit chip address, a read/write bit, and an 11-bit
RAM/register address. The control port knows how many data
bytes to expect based on the address given in the first three bytes.
The total number of bytes for a single-location write command
can vary from four bytes (for a control register write) to eight
bytes (for a program RAM write). Burst mode can be used to fill
contiguous register or RAM locations. A burst mode write begins
by writing the address and data of the first RAM or register location
to be written. Rather than ending the control port transaction
(by issuing a stop command in I2C mode or by bringing the
CLATCH signal high in SPI mode after the data-word), as
would be done in a single-address write, the next data-word
can be written immediately without specifying its address. The
Rev. 0 | Page 29 of 52
ADAU1702
ADAU1702 control port auto-increments the address of each write
even across the boundaries of the different RAMs and registers.
Table 23 and Table 25 show examples of burst mode writes.
Table 22. Parameter RAM Read/Write Format (Single Address)
Byte 0
chip_adr [6:0], W/R
Byte 1
000000, param_adr [9:8]
Byte 2
param_adr [7:0]
Byte 3
0000, param [27:24]
Bytes 4:6
param [23:0]
Table 23. Parameter RAM Block Read/Write Format (Burst Mode)
Byte 0
chip_adr [6:0], W/R
Byte 1
000000,
param_adr [9:8]
Byte 2
param_adr [7:0]
Byte 3
0000, param [27:24]
Bytes 4:6
param [23:0]
<—param_adr—>
Bytes 7:10
Bytes 11:14
param_adr + 1
param_adr + 2
Bytes 8:12
Bytes 13:17
prog_adr + 1
prog_adr + 2
Table 24. Program RAM Read/Write Format (Single Address)
Byte 0
chip_adr [6:0], W/R
Byte 1
Byte 2
Bytes 3:7
00000, prog_adr [10:8]
prog_adr [7:0]
prog [39:0]
Table 25. Program RAM Block Read/Write Format (Burst Mode)
Byte 0
chip_adr [6:0], W/R
Byte 1
00000, prog_adr [10:8]
Byte 2
prog_adr [7:0]
Bytes 3:7
prog [39:0]
<—prog_adr—>
Table 26. Control Register Read/Write Format (Core, Serial Out 0, Serial Out 1)
Byte 0
chip_adr [6:0], W/R
Byte 1
0000, reg_adr [11:8]
Byte 2
reg_adr [7:0]
Byte 3
data [15:8]
Byte 4
data [7:0]
Table 27. Control Register Read/Write Format (RAM Configuration, Serial Input)
Byte 0
chip_adr [6:0], W/R
Byte 1
0000, reg_adr [11:8]
Byte 2
reg_adr [7:0]
Byte 3
data [7:0]
Table 28. Data Capture Register Write Format
Byte 0
chip_adr [6:0], W/R
1
2
Byte 1
0000, data_capture_adr [11:8]
Byte 2
data_capture_adr [7:0]
Byte 3
000, progCount [10:6] 1
Byte 4
progCount [5:0]1, regSel [1:0] 2
ProgCount [10:0] is the value of the program counter where the data capture occurs (the table of values is generated by the SigmaStudio compiler).
RegSel [1:0] selects one of four registers (see the 2074 to 2075 (0x081A to 0x081B)—Data Capture Registers section).
Table 29. Data Capture (Control Port Readback) Register Read Format
Byte 0
chip_adr [6:0], W/R
Byte 1
0000, data_capture_adr [11:8]
Byte 2
data_capture_adr [7:0]
Bytes 3:5
data [23:0]
Table 30. Safeload Address Register Write Format
Byte 0
chip_adr [6:0], W/R
Byte 1
0000, safeload_adr [11:8]
Byte 2
safeload_adr [7:0]
Byte 3
000000, param_adr [9:8]
Byte 4
param_adr [7:0]
Table 31. Safeload Data Register Write Format
Byte 0
chip_adr [6:0], W/R
Byte 1
0000, safeload_adr [11:8]
Byte 2
safeload_adr [7:0]
Byte 3
00000000
Rev. 0 | Page 30 of 52
Byte 4
0000, data [27:24]
Bytes 5:7
data [23:0]
ADAU1702
CONTROL REGISTER MAP
Table 32. Register Map 1
MSB
Reg
(Dec)
0x0800
2048
0x0801
2049
4
0x0802
2050
4
0x0803
2051
4
0x0804
2052
4
0x0805
2053
4
0x0806
2054
4
0x0807
2055
4
0x0808
0x0809
0x080A
0x080B
2056
2057
2058
2059
2
2
2
2
0x080C 2060
0x080D 2061
2
5
0x080E
0x080F
0x0810
0x0811
0x0812
0x0813
0x0814
0x0815
0x0816
0x0817
0x0818
0x0819
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
D31
D15
0
IF15
D30
D14
0
IF14
D29
D13
0
IF13
D28
D12
0
IF12
D27
D11
IF27
IF11
D26
D10
IF26
IF10
D25
D9
IF25
IF09
D24
D8
IF24
IF08
Interface 0 [31:16]
Interface 0 [15:0]
Interface 0 [31:16]
Interface 0 [15:0]
Interface 0 [31:16]
Interface 0 [15:0]
Interface 0 [31:16]
Interface 0 [15:0]
Interface 0 [31:16]
Interface 0 [15:0]
Interface 0 [31:16]
Interface 0 [15:0]
Interface 0 [31:16]
Interface 0 [15:0]
GPIO pin setting
Auxiliary ADC Data 0
Auxiliary ADC Data 1
Auxiliary ADC Data 2
0
IF15
0
IF15
0
IF15
0
IF15
0
IF15
0
IF15
0
IF15
0
0
0
0
0
IF14
0
IF14
0
IF14
0
IF14
0
IF14
0
IF14
0
IF14
0
0
0
0
0
IF13
0
IF13
0
IF13
0
IF13
0
IF13
0
IF13
0
IF13
0
0
0
0
0
IF12
0
IF12
0
IF12
0
IF12
0
IF12
0
IF12
0
IF12
0
0
0
0
IF27
IF11
IF27
IF11
IF27
IF11
IF27
IF11
IF27
IF11
IF27
IF11
IF27
IF11
MP11
AA11
AA11
AA11
IF26
IF10
IF26
IF10
IF26
IF10
IF26
IF10
IF26
IF10
IF26
IF10
IF26
IF10
MP10
AA10
AA10
AA10
IF25
IF09
IF25
IF09
IF25
IF09
IF25
IF09
IF25
IF09
IF25
IF09
IF25
IF09
MP09
AA09
AA09
AA09
IF24
IF08
IF24
IF08
IF24
IF08
IF24
IF08
IF24
IF08
IF24
IF08
IF24
IF08
MP08
AA08
AA08
AA08
IF23
IF07
IF23
IF07
IF23
IF07
IF23
IF07
IF23
IF07
IF23
IF07
IF23
IF07
MP07
AA07
AA07
AA07
IF22
IF06
IF22
IF06
IF22
IF06
IF22
IF06
IF22
IF06
IF22
IF06
IF22
IF06
MP06
AA06
AA06
AA06
IF21
IF05
IF21
IF05
IF21
IF05
IF21
IF05
IF21
IF05
IF21
IF05
IF21
IF05
MP05
AA05
AA05
AA05
IF20
IF04
IF20
IF04
IF20
IF04
IF20
IF04
IF20
IF04
IF20
IF04
IF20
IF04
MP04
AA04
AA04
AA04
IF19
IF03
IF19
IF03
IF19
IF03
IF19
IF03
IF19
IF03
IF19
IF03
IF19
IF03
MP03
AA03
AA03
AA03
IF18
IF02
IF18
IF02
IF18
IF02
IF18
IF02
IF18
IF02
IF18
IF02
IF18
IF02
MP02
AA02
AA02
AA02
IF17
IF01
IF17
IF01
IF17
IF01
IF17
IF01
IF17
IF01
IF17
IF01
IF17
IF01
MP01
AA01
AA01
AA01
IF16
IF00
IF16
IF00
IF16
IF00
IF16
IF00
IF16
IF00
IF16
IF00
IF16
IF00
MP00
AA00
AA00
AA00
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
Auxiliary ADC Data 3
Reserved [39:32]
Reserved [31:16]
Reserved [15:0]
Reserved [39:32]
Reserved [31:16]
Reserved [15:0]
Reserved [39:32]
Reserved [31:16]
Reserved [15:0]
Safeload Data 0 [39:32]
Safeload Data 0 [31:16]
Safeload Data 0 [15:0]
Safeload Data 1 [39:32]
Safeload Data 1 [31:16]
Safeload Data 1 [15:0]
Safeload Data 2 [39:32]
Safeload Data 2 [31:16]
Safeload Data 2 [15:0]
Safeload Data 3 [39:32]
Safeload Data 3 [31:16]
Safeload Data 3 [15:0]
Safeload Data 4 [39:32]
Safeload Data 4 [31:16]
Safeload Data 4 [15:0]
Safeload Address 0
Safeload Address 1
Safeload Address 2
Safeload Address 3
Safeload Address 4
0
0
0
0
AA11 AA10 AA09 AA08 AA07
RSVD
RSVD RSVD RSVD RSVD RSVD
RSVD RSVD RSVD RSVD RSVD
RSVD
RSVD RSVD RSVD RSVD RSVD
RSVD RSVD RSVD RSVD RSVD
RSVD
RSVD RSVD RSVD RSVD RSVD
RSVD RSVD RSVD RSVD RSVD
SD39
SD27 SD26 SD25 SD24 SD23
SD11 SD10 SD09 SD08 SD07
SD39
SD27 SD26 SD25 SD24 SD23
SD11 SD10 SD09 SD08 SD07
SD39
SD27 SD26 SD25 SD24 SD23
SD11 SD10 SD09 SD08 SD07
SD39
SD27 SD26 SD25 SD24 SD23
SD11 SD10 SD09 SD08 SD07
SD39
SD27 SD26 SD25 SD24 SD23
SD11 SD10 SD09 SD08 SD07
SA11 SA10 SA09 SA08 SA07
SA11 SA10 SA09 SA08 SA07
SA11 SA10 SA09 SA08 SA07
SA11 SA10 SA09 SA08 SA07
SA11 SA10 SA09 SA08 SA07
AA06
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
SD38
SD22
SD06
SD38
SD22
SD06
SD38
SD22
SD06
SD38
SD22
SD06
SD38
SD22
SD06
SA06
SA06
SA06
SA06
SA06
AA05
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
SD37
SD21
SD05
SD37
SD21
SD05
SD37
SD21
SD05
SD37
SD21
SD05
SD37
SD21
SD05
SA05
SA05
SA05
SA05
SA05
AA04
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
SD36
SD20
SD04
SD36
SD20
SD04
SD36
SD20
SD04
SD36
SD20
SD04
SD36
SD20
SD04
SA04
SA04
SA04
SA04
SA04
AA03
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
SD35
SD19
SD03
SD35
SD19
SD03
SD35
SD19
SD03
SD35
SD19
SD03
SD35
SD19
SD03
SA03
SA03
SA03
SA03
SA03
AA02
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
SD34
SD18
SD02
SD34
SD18
SD02
SD34
SD18
SD02
SD34
SD18
SD02
SD34
SD18
SD02
SA02
SA02
SA02
SA02
SA02
AA01
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
SD33
SD17
SD01
SD33
SD17
SD01
SD33
SD17
SD01
SD33
SD17
SD01
SD33
SD17
SD01
SA01
SA01
SA01
SA01
SA01
AA00
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
SD32
SD16
SD00
SD32
SD16
SD00
SD32
SD16
SD00
SD32
SD16
SD00
SD32
SD16
SD00
SA00
SA00
SA00
SA00
SA00
0x0000
0x00
0x0000
0x0000
0x00
0x0000
0x0000
0x00
0x0000
0x0000
0x00
0x0000
0x0000
0x00
0x0000
0x0000
0x00
0x0000
0x0000
0x00
0x0000
0x0000
0x00
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
No.
of
Bytes Name
4
Interface 0 [31:16]
Interface 0 [15:0]
Reg
(Hex)
5
5
5
5
5
5
5
2
2
2
2
2
LSB
D39
D23
D7
IF23
IF07
RSVD RSVD RSVD RSVD
RSVD RSVD RSVD RSVD
RSVD RSVD RSVD RSVD
RSVD RSVD RSVD RSVD
RSVD RSVD RSVD RSVD
RSVD RSVD RSVD RSVD
SD31 SD30 SD29 SD28
SD15 SD14 SD13 SD12
SD31 SD30 SD29 SD28
SD15 SD14 SD13 SD12
SD31 SD30 SD29 SD28
SD15 SD14 SD13 SD12
SD31 SD30 SD29 SD28
SD15 SD14 SD13 SD12
SD31
SD15
0
0
0
0
0
SD30
SD14
0
0
0
0
0
SD29
SD13
0
0
0
0
0
SD28
SD12
0
0
0
0
0
Rev. 0 | Page 31 of 52
D38
D22
D6
IF22
IF06
D37
D21
D5
IF21
IF05
D36
D20
D4
IF20
IF04
D35
D19
D3
IF19
IF03
D34
D18
D2
IF18
IF02
D33
D17
D1
IF17
IF01
D32
D16
D0
IF16
IF00
Default
0x0000
0x0000
ADAU1702
MSB
Reg
(Hex)
Reg
(Dec)
0x081A
0x081B
0x081C
0x081D
0x081E
0x081F
0x0820
2074
2075
2076
2077
2078
2079
2080
0x0821
2081
0x0822
2082
0x0823
0x0824
0x0825
0x0826
0x0827
2083
2084
2085
2086
2087
1
No.
of
Bytes Name
2
Data Capture 0
2
Data Capture 1
2
DSP core control
1
Reserved
2
Serial output control
1
Serial input control
3
MP Pin Config. 0 [23:16]
MP Pin Config. 0 [15:0]
3
MP Pin Config. 1 [23:16]
MP Pin Config. 1 [15:0]
2
Auxiliary ADC and
Power Control
2
Reserved
2
Auxiliary ADC Enable
2
Reserved
2
Oscillator Power-Down
2
DAC Setup
D31
D15
0
0
RSVD
D30
D14
0
0
RSVD
D29
D13
0
0
GD1
D28
D12
0
0
GD0
D27
D11
PC09
PC09
RSVD
D26
D10
PC08
PC08
RSVD
D25
D9
PC07
PC07
RSVD
D24
D8
PC06
PC06
AACW
RSVD
AAEN
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
D39
D23
D7
PC05
PC05
GPCW
RSVD
OLF0
0
MP53
MP13
D38
D22
D6
PC04
PC04
IFCW
RSVD
FST
0
MP52
MP12
D37
D21
D5
PC03
PC03
IST
RSVD
TDM
0
MP51
MP11
D36
D20
D4
PC02
PC02
ADM
RSVD
MSB2
ILP
MP50
MP10
D35
D19
D3
PC01
PC01
DAM
RSVD
MSB1
IBP
MP43
MP03
D34
D18
D2
PC00
PC00
CR
RSVD
MSB0
M2
MP42
MP02
D33
D17
D1
RS01
RS01
SR1
RSVD
OWL1
M1
MP41
MP01
LSB
D32
D16
D0
RS00
RS00
SR0
RSVD
OWL0
M0
MP40
MP00
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
RSVD
OPD
RSVD
RSVD
RSVD
RSVD
RSVD
DS1
RSVD
RSVD
RSVD
RSVD
DS0
Default
0x0000
0x0000
0x0000
0x00
0
0
OLRP OBP M/S OBF1 OBF0 OLF1
0x0000
0x00
0x00
MP33 MP32 MP31 MP30 MP23 MP22 MP21 MP20
0x0000
MP113 MP112 MP111 MP110 MP103 MP102 MP101 MP100 0x00
MP93 MP92 MP91 MP90 MP83 MP82 MP81 MP80 MP73 MP72 MP71 MP70 MP63 MP62 MP61 MP60 0x0000
RSVD RSVD RSVD RSVD RSVD RSVD FIL1 FIL0 AAPD VBPD VRPD RSVD D0PD D1PD D2PD D3PD 0x0000
Shading indicates that registers do not fill these locations, so control bits do not exist in these locations.
Rev. 0 | Page 32 of 52
0x0000
0x0000
0x0000
0x0000
0x0000
ADAU1702
CONTROL REGISTER DETAILS
2048 TO 2055 (0X0800 TO 0X0807)—INTERFACE REGISTERS
The interface registers are used in self-boot mode to save
parameters that need to be written to the external EEPROM.
The ADAU1702 then recalls these parameters from the
EEPROM after the next reset or power-up. Therefore, system
parameters such as volume and EQ settings can be saved during
power-down and recalled the next time the system is turned on.
There are eight 32-bit interface registers, which allow eight
28-bit (plus zero-padding) parameters to be saved. The
parameters to be saved in these registers are selected in the
graphical programming tools. These registers are updated with
their corresponding parameter RAM data once per sample period.
An edge, which can be set to be either rising or falling, triggers
the ADAU1702 to write the current contents of the interface
registers to the EEPROM. See the Self-Boot section for details.
The user can write directly to the interface registers after the
interface registers control port write mode (IFCW) in the DSP core
control register has been set. In this mode, the data in the registers
is written from the control port, not from the DSP core.
Table 33.
D31
D15
0
IF15
D30
D14
0
IF14
D29
D13
0
IF13
D28
D12
0
IF12
D27
D11
IF27
IF11
D26
D10
IF26
IF10
D25
D9
IF25
IF09
D24
D8
IF24
IF08
D23
D7
IF23
IF07
D22
D6
IF22
IF06
Table 34.
Bit Name
IF [27:0]
Description
Interface register 28-bit parameter
Rev. 0 | Page 33 of 52
D21
D5
IF21
IF05
D20
D4
IF20
IF04
D19
D3
IF19
IF03
D18
D2
IF18
IF02
D17
D1
IF17
IF01
D16
D0
IF16
IF00
Default
0x0000
0x0000
ADAU1702
2056 (0x808)—GPIO PIN SETTING REGISTER
This register allows the user to set the GPIO pins through the control port. High or low settings can be directly written to or read from
this register after setting the GPIO pin setting register control port write mode (GPCW) in the core control register. This register is
updated once every LRCLK frame (1/fS).
Table 35.
D15
0
D14
0
D13
0
D12
0
D11
MP11
D10
MP10
D9
MP09
D8
MP08
D7
MP07
D6
MP06
D5
MP05
D4
MP04
D3
MP03
Table 36.
Bit Name
MP [11:0]
Description
Setting of multipurpose pin when controlled through SPI or I2C
Rev. 0 | Page 34 of 52
D2
MP02
D1
MP01
D0
MP00
Default
0x0000
ADAU1702
2057 TO 2060 (0x809 TO 0x80C)—AUXILIARY ADC DATA REGISTERS
These registers hold the data generated by the 4-channel
auxiliary ADC. The ADCs have eight bits of precision and can
be extended to 12 bits if filtering is selected in Bits FIL [1:0] of
the auxiliary ADC and power control register. The SigmaDSP
program reads this data as a 1.11 format data-word with a range
of 0 to 1.0. This data-word is mapped to the 5.23 format
parameter word with the four MSBs and 12 LSBs set to 0. A
full-scale code of 255 results in a value of 1.0. These registers
can be written to directly if the auxiliary ADC data registers
control port write mode (AACW) bit is set in the DSP core
control register.
Table 37.
D15
0
D14
0
D13
0
D12
0
D11
AA11
D10
AA10
D9
AA09
D8
AA08
D7
AA07
D6
AA06
Table 38.
Bit Name
AA [11:0]
Description
Auxiliary ADC output data, MSB first
Rev. 0 | Page 35 of 52
D5
AA05
D4
AA04
D3
AA03
D2
AA02
D1
AA01
D0
AA00
Default
0x0000
ADAU1702
2064 TO 2068 (0x0810 TO 0x814)—SAFELOAD DATA REGISTERS
Many applications require real-time microcontroller control of
signal processing parameters, such as filter coefficients, mixer
gains, multichannel virtualizing parameters, or dynamics
processing curves. When controlling a biquad filter, for
example, all of the parameters must be updated at the same
time. Doing so prevents the filter from executing with a mix of
old and new coefficients for one or two audio frames, thus
avoiding temporary instability and transients that may take a
long time to decay. To accomplish this, the ADAU1702 uses
safeload data registers to simultaneously load a set of five 28-bit
values to the desired parameter RAM address. Five registers are
used because a biquad filter uses five coefficients and, as
previously mentioned, it is desirable to do a complete update in
one transaction.
initiate the loading into RAM. Each of the five safeload registers
takes one of the 512 core instructions to load into the parameter
RAM. The total program lengths should therefore be limited to
507 cycles (512 minus 5) to ensure that the SigmaDSP core
always has at least five cycles available. The safeload is
guaranteed to occur within one LRCLK period (21 μs for a fS of
48 kHz) of the initiate safeload transfer bit being set.
The safeload logic automatically sends data to be loaded into
RAM from only those safeload registers that have been written
to since the last safeload operation. For example, if two
parameters are to be updated in the RAM, only two of the five
safeload registers must be written. When the initiate safeload
transfer bit is asserted, only data from those two registers are
sent to the RAM; the other three registers are not sent to the
RAM and may hold old or invalid data.
The first step in performing a safeload operation is writing the
parameter address to one of the safeload address registers (2069
to 2073). The 10-bit data-word to be written is the address in
parameter RAM to which the safeload is being performed. After
this address is written, the 28-bit data-word can be written to
the corresponding safeload data register (2064 to 2068).
Table 39. Safeload Address and Data Register Mapping
Safeload
Register
0
1
2
3
4
The data formats for these writes are detailed in Table 30 and
Table 31. Table 39 shows how each of the five address registers
maps to its corresponding data register.
Safeload
Address Register
2069
2070
2071
2072
2073
Safeload
Data Register
2064
2065
2066
2067
2068
After the address and data registers are loaded, the initiate
safeload transfer bit in the core control register should be set to
Table 40.
D31
D15
D30
D14
D29
D13
D28
D12
D27
D11
D26
D10
D25
D9
D24
D8
SD31
SD15
SD30
SD14
SD29
SD13
SD28
SD12
SD27
SD11
SD26
SD10
SD25
SD09
SD24
SD08
D39
D23
D7
SD39
SD23
SD07
D38
D22
D6
SD38
SD22
SD06
D37
D21
D5
SD37
SD21
SD05
D36
D20
D4
SD36
SD20
SD04
D35
D19
D3
SD35
SD19
SD03
D34
D18
D2
SD34
SD18
SD02
D33
D17
D1
SD33
SD17
SD01
D32
D16
D0
SD32
SD16
SD00
Default
0x00
0x0000
0x0000
Table 41.
Bit Name
SD [39:0]
Safeload Data
Description
Data (program, parameters, register contents) to be loaded into the RAMs or registers
2069 TO 2073 (0x0815 TO 0x819) SAFELOAD ADDRESS REGISTERS
Table 42.
D15
0
D14
0
D13
0
D12
0
D11
SA11
D10
SA10
D9
SA09
D8
SA08
D7
SA07
D6
SA06
D5
SA05
D4
SA04
D3
SA03
Table 43.
Bit Name
SA [11:0]
Safeload Address
Description
Address of data that is to be loaded into the RAMs or registers
Rev. 0 | Page 36 of 52
D2
SA02
D1
SA01
D0
SA00
Default
0x0000
ADAU1702
2074 TO 2075 (0X081A TO 0X081B)—DATA CAPTURE REGISTERS
The ADAU1702 data capture feature allows the data at any node
in the signal processing flow to be sent to one of two readable
registers. This feature is useful for monitoring and displaying
information about internal signal levels or compressor/limiter
activity.
The captured data is in 5.19, twos complement data format,
which comes from the internal 5.23 data-word with the four
LSBs truncated.
The data that must be written to set up the data capture is a
concatenation of the 10-bit program count index with the 2-bit
register select field. The capture count and register select values
that correspond to the desired point to be monitored in the
signal processing flow can be found in a file output from the
program compiler. The capture registers can be accessed by
reading from Location 2074 and Location 2075. The format for
reading and writing to the data capture registers is shown in
Table 28 and Table 29.
For each of the data capture registers, a capture count and a
register select must be set. The capture count is a number
between 0 and 1023 that corresponds to the program step
number where the capture is to occur. The register select field
programs one of four registers in the DSP core that transfers
this information to the data capture register when the program
counter reaches this step.
Table 44.
D15
0
D14
0
D13
0
D12
0
D11
PC09
D10
PC08
D9
PC07
D8
PC06
D7
PC05
D6
PC04
D5
PC03
Table 45.
Bit Name
PC [9:0]
RS [1:0]
Description
10-bit program counter address
Select the register to be transferred to the data capture output
RS [1:0]
Register
00
Multiplier X input (Mult_X_input)
01
Multiplier Y input (Mult_Y_input)
10
Multiplier-accumulator output (MAC_out)
11
Accumulator feedback (Accum_fback)
Rev. 0 | Page 37 of 52
D4
PC02
D3
PC01
D2
PC00
D1
RS01
D0
RS00
Default
0x0000
ADAU1702
2076 (0x081C)—DSP CORE CONTROL REGISTER
Table 46.
D15
RSVD
D14
RSVD
D13
GD1
D12
GD0
D11
RSVD
D10
RSVD
D9
RSVD
D8
AACW
D7
GPCW
D6
IFCW
D5
IST
D4
ADM
D3
DAM
D2
CR
D1
SR1
D0
SR0
Default
0x0000
Table 47. DSP Core Control Register
Bit Name
GD [1:0]
GPIO Debounce Control
AACW
Auxiliary ADC Data
Registers Control Port
Write Mode
GPCW
GPIO Pin Setting Register
Control Port Write Mode
IFCW
Interface Registers
Control Port Write Mode
IST
Initiate Safeload Transfer
ADM
Mute ADCs
DAM
Mute DACs
CR
Clear Internal
Registers to 0
SR [1:0]
Sample Rate
Description
Sets debounce time of multipurpose pins that are set as GPIO inputs.
GD [1:0]
Time (ms)
00
20
01
40
10
10
11
5
Setting this bit allows data to be written directly to the auxiliary ADC data registers (2057 to 2060) from the
control port. When this bit is set, the auxiliary ADC data registers ignores the settings on the multipurpose pins.
When this bit is set, the GPIO pin setting register (2056) can be written to directly from the control port and
this register ignores the input settings on the multipurpose pins.
When this bit is set, data can be written directly to the interface registers (2048 to 2055) from the control port.
In that state, the interface registers are not written from the SigmaDSP program.
Setting this bit to 1 initiates a safeload transfer to the parameter RAM. This bit is automatically cleared when
the operation is complete. There are five safeload register pairs (address/data); only those registers that have
been written since the last safeload event are transferred to the parameter RAM.
This bit mutes the output of the ADCs. The bit defaults to 0 and is active low; therefore, it must be set to 1 to
transmit audio signals from the ADCs.
This bit mutes the output of the DACs. The bit defaults to 0 and is active low; therefore, it must be set to 1 to
transmit audio signals from the DACs.
This bit defaults to 0 and is active low. It must be set to 1 for a signal to pass through the SigmaDSP core.
These bits set the number of DSP instructions for every sample and the sample rate at which the ADAU1702
operates. At the default setting of 1×, there are 512 instructions per audio sample. This setting should be used
with sample rates such as 48 kHz and 44.1 kHz.
At the 2× setting, the number of instructions per frame is halved to 256 and the ADCs and DACs nominally run
at a 96 kHz sample rate.
At the 4× setting, there are 128 instructions per cycle and the converters run at a 192 kHz sample rate.
SR [1:0] Setting
00
1× (512 instructions)
01
2× (256 instructions)
10
4× (128 instructions)
11
Reserved
Rev. 0 | Page 38 of 52
ADAU1702
2078 (0x081E)—SERIAL OUTPUT CONTROL REGISTER
Table 48.
D15
0
D14
0
D13
OLRP
D12
OBP
D11
M/S
D10
OBF1
D9
OBF0
D8
OLF1
D7
OLF0
D6
FST
D5
TDM
D4
MSB2
D3
MSB1
D2
MSB0
D1
OWL1
D0
OWL0
Default
0x0000
Table 49.
Bit Name
OLRP
OUTPUT_LRCLK Polarity
OBP
OUTPUT_BCLK Polarity
M/S
Master/Slave
OBF [1:0]
OUTPUT_BCLK Freq
(Master Mode Only)
OLF [1:0]
OUTPUT_LRCLK Freq
(Master Mode Only)
FST
Frame Sync Type
TDM
TDM Enable
MSB [2:0]
MSB Position
OWL [1:0]
Output Word Length
Description
When this bit is set to 0, the left-channel data is clocked when OUTPUT_LRCLK is low and the right-channel
data is clocked when OUTPUT_LRCLK is high. When this bit is set to 1, the right-channel data is clocked when
OUTPUT_LRCLK is low and the left-channel data is clocked when OUTPUT_LRCLK is high.
This bit controls on which edge of the bit clock the output data is clocked. Data changes on the falling edge
of OUTPUT_BCLK when this bit is set to 0 and on the rising edge when this bit is set to 1.
This bit sets whether the output port is a clock master or slave. The default setting is slave; on power-up, the
OUTPUT_BCLK and OUTPUT_LRCLK pins are set as inputs until this bit is set to 1, at which time they become
clock outputs.
When the output port is being used as a clock master, these bits set the frequency of the output bit clock,
which is divided down from an internal 1024 × fS clock (49.152 MHz for a fS of 48 kHz).
OBF [1:0]
Setting
00
Internal clock/16
01
Internal clock/8
10
Internal clock/4
11
Internal clock/2
When the output port is used as a clock master, these bits set the frequency of the output word clock on the
OUTPUT_LRCLK pins, which is divided down from an internal 1024 × fS clock (49.152 MHz for a fS of 48 kHz).
OLF [1:0]
Setting
00
Internal clock/1024
01
Internal clock/512
10
Internal clock/256
11
Reserved
This bit sets the type of signal on the OUTPUT_LRCLK pins. When this bit is set to 0, the signal is a word clock
with a 50% duty cycle; when this bit is set to 1, the signal is a pulse with a duration of one bit clock at the
beginning of the data frame.
Setting this bit to 1 changes the output port from four serial stereo outputs to a single 8-channel TDM output
stream on the SDATA_OUT0 pin (MP6).
These three bits set the position of the MSB of data with respect to the LRCLK edge. The data output of the
ADAU1702 is always MSB first.
MSB [2:0]
Setting
000
Delay by 1
001
Delay by 0
010
Delay by 8
011
Delay by 12
100
Delay by 16
101
Reserved
111
Reserved
These bits set the word length of the output data-word. All bits following the LSB are set to 0.
OWL [1:0]
Setting
00
24 bits
01
20 bits
10
16 bits
11
Reserved
Rev. 0 | Page 39 of 52
ADAU1702
2079 (0x081F)—SERIAL INPUT CONTROL REGISTER
Table 50.
D7
0
D6
0
D5
0
D4
ILP
D3
IBP
D2
M2
D1
M1
D0
M0
Default
0x00
Table 51.
Bit Name
ILP
INPUT_LRCLK Polarity
IBP
INPUT_BCLK Polarity
M [2:0]
Serial Input Mode
Description
When this bit is set to 0, the left-channel data on the SDATA_INx pins is clocked when INPUT_LRCLK is low and
the right-channel data is clocked when INPUT_LRCLK is high. When this bit is set to 1, the clocking of these
channels is reversed. In TDM mode when this bit is set to 0, data is clocked in, starting with the next appropriate
BCLK edge (set in Bit 3 of this register) after a falling edge on the INPUT_LRCLK pin. When this bit is set to 1 and
the device is running in TDM mode, the input data is valid on the BCLK edge after a rising edge on the word
clock (INPUT_LRCLK). INPUT_LRCLK can also operate with a pulse input, rather than a clock. In this case, the first
edge of the pulse is used by the ADAU1702 to start the data frame. When this polarity bit is set to 0, a low pulse
should be used; when the bit it set to 1, a high pulse should be used.
This bit controls on which edge of the bit clock the input data changes and on which edge it is clocked. Data
changes on the falling edge of INPUT_BCLK when this bit is set to 0 and on the rising edge when this bit is set at 1.
These two bits control the data format that the input port expects to receive. Bit 3 and Bit 4 of this control
register override the settings of Bits 2:0; therefore, all four bits must be changed together for proper operation
in some modes. The clock diagrams for these modes are shown in Figure 31, Figure 32, and Figure 33. Note that
for left-justified and right-justified modes the LRCLK polarity is high and then low, which is opposite from the
default setting of ILP.
When these bits are set to accept a TDM input, the ADAU1702 data starts after the edge defined by ILP. The
ADAU1702 TDM data stream should be input on Pin SDATA_IN0. Figure 34 shows a TDM stream with a high-tolow triggered LRCLK and data changing on the falling edge of the BCLK. The ADAU1702 expects the MSB of
each data slot to be delayed by one BCLK from the beginning of the slot, as it would in stereo I2S format. In TDM
mode, Channel 0 to Channel 3 are in the first half of the frame, and Channel 4 to Channel 7 are in the second
half. Figure 35 shows an example of a TDM stream running with a pulse word clock, which is used to interface to
ADI codecs in auxiliary mode. To work in this mode with either the input or output serial ports, set the
ADAU1702 to begin the frame on the rising edge of LRCLK, to change data on the falling edge of BCLK, and to
delay the MSB position from the start of the word clock by one BCLK.
M [2:0]
Setting
000
I2S
001
Left justified
010
TDM
011
Right justified, 24 bits
100
Right justified, 20 bits
101
Right justified, 18 bits
110
Right justified, 16 bits
111
Reserved
Rev. 0 | Page 40 of 52
ADAU1702
2080 TO 2081 (0x0820 TO 0x0821)—MULTIPURPOSE PIN CONFIGURATION REGISTERS
each pin’s 4-bit configuration inverts the input to or output
from the pin. The internal pull-up resistor (approximately
10 kΩ) of each MP pin is enabled when it is set as a digital input
(either a GPIO input or a serial data port input).
Each multipurpose pin can be set to different functions from
these registers (2080 to 2081). The two 3-byte registers are
broken up into 12 4-bit (nibble) sections that each control a
different MP pin. Table 54 lists the function of each nibble
setting within the MP pin configuration registers. The MSB of
Table 52. Register 2080
D15
D14
D13
D12
D11
D10
D9
D8
MP33
MP32
MP31
MP30
MP23
MP22
MP21
MP20
D23
D7
MP53
MP13
D22
D6
MP52
MP12
D21
D5
MP51
MP11
D20
D4
MP50
MP10
D19
D3
MP43
MP03
D18
D2
MP42
MP02
D17
D1
MP41
MP01
D16
D0
MP40
MP00
Default
0x00
0x0000
D18
D2
MP102
MP62
D17
D1
MP101
MP61
D16
D0
MP100
MP60
Default
0x00
0x0000
Table 53. Register 2081
D15
D14
D13
D12
D11
D10
D9
D8
MP93
MP92
MP91
MP90
MP83
MP82
MP81
MP80
D23
D7
MP113
MP73
D22
D6
MP112
MP72
D21
D5
MP111
MP71
Table 54.
Bit Name
MPx [3:0]
Description
Set the function of each multipurpose pin
MPx [3:0]
Setting
1111
Auxiliary ADC input (see Table 63)
1110
Reserved
1101
Reserved
1100
Serial data port—inverted (see Table 65)
1011
Open-collector output—inverted
1010
GPIO output—inverted
1001
GPIO input, no debounce—inverted
1000
GPIO input, debounced—inverted
0111
N/A
0110
Reserved
0101
Reserved
0100
Serial data port (see Table 65)
0011
Open-collector output
0010
GPIO output
0001
GPIO input, no debounce
0000
GPIO input, debounced
Rev. 0 | Page 41 of 52
D20
D4
MP110
MP70
D19
D3
MP103
MP63
ADAU1702
2082 (0x0822)—AUXILIARY ADC AND POWER CONTROL
Table 55.
D15
RSVD
D14
RSVD
D13
RSVD
D12
RSVD
D11
RSVD
D10
RSVD
D9
FIL1
D8
FIL0
D7
D6
AAPD VBPD
D5
VRPD
D4
RSVD
D3
D0PD
D2
D1
D1PD D2PD
D0
D3PD
Default
0x0000
Table 56.
Bit Name
FIL [1:0]
AAPD
VBPD
VRPD
D0PD
D1PD
D2PD
D3PD
Description
Auxiliary ADC filtering
FIL [1:0]
Setting
00
4-bit hysteresis (12-bit level)
01
5-bit hysteresis (12-bit level)
10
Filter and hysteresis bypassed
11
Low-pass filter bypassed
ADC power-down (both ADCs)
Voltage reference buffer power-down
Voltage reference power-down
DAC0 power-down
DAC1 power-down
DAC2 power-down
DAC3 power-down
2084 (0x0824)—AUXILIARY ADC ENABLE
Table 57.
D15
AAEN
D14
RSVD
D13
RSVD
D12
RSVD
D11
RSVD
D10
RSVD
D9
RSVD
D8
RSVD
D7
RSVD
D6
RSVD
D5
RSVD
D4
RSVD
D3
RSVD
D2
RSVD
D8
RSVD
D7
RSVD
D6
RSVD
D5
RSVD
D4
RSVD
D3
RSVD
D2
OPD
D1
RSVD
D0
RSVD
Default
0x0000
Table 58.
Bit Name
AAEN
Description
Enable the auxiliary ADC
2086 (0x0826)—OSCILLATOR POWER-DOWN
Table 59.
D15
RSVD
D14
RSVD
D13
RSVD
D12
RSVD
D11
RSVD
D10
RSVD
D9
RSVD
Table 60.
Bit Name
OPD
Description
Power-down the oscillator
Rev. 0 | Page 42 of 52
D1
RSVD
D0
RSVD
Default
0x0000
ADAU1702
2087 (0x0827)—DAC SETUP
To properly initialize the DACs, Bits DS [1:0] in this register should be set to 01.
Table 61.
D15
RSVD
D14
RSVD
D13
RSVD
D12
RSVD
D11
RSVD
D10
RSVD
D9
RSVD
D8
RSVD
D7
RSVD
D6
RSVD
Table 62.
Bit Name
DS [1:0]
Description
DAC setup
DS [1:0]
00
01
10
11
Setting
Reserved
Initialize DACs
Reserved
Reserved
Rev. 0 | Page 43 of 52
D5
RSVD
D4
RSVD
D3
RSVD
D2
RSVD
D1
DS1
D0
DS0
Default
0x0000
ADAU1702
MULTIPURPOSE PINS
The ADAU1702 has 12 multipurpose (MP) pins that can be
individually programmed to be used as serial data inputs, serial
data outputs, digital control inputs/outputs to and from the
SigmaDSP core, or inputs to the 4-channel auxiliary ADC. These
pins allow the ADAU1702 to be used with external ADCs and
DACs. They also use analog or digital inputs to control settings
such as volume control, or use output digital signals to drive
LED indicators.
AUXILIARY ADC
The ADAU1702 has a 4-channel, auxiliary, 8-bit ADC that can
be used in conjunction with a potentiometer to control volume,
tone, or other parameter settings in the DSP program. Each of
the four channels is sampled at the audio sampling frequency (fS).
Full-scale input on this ADC is 3.3 V, so the step size is approximately 13 mV (3.3 V/256 steps). The input resistance of the ADC is
approximately 20 kΩ. Table 63 indicates which four MP pins are
mapped to the four channels of the auxiliary ADC. The auxiliary
ADC is enabled for those pins by writing 1111 to the appropriate
portion of the multipurpose pin configuration registers.
The auxiliary ADC is turned on by setting the AAEN bit of the
auxiliary ADC enable register (see Table 58).
Noise on the ADC input can cause the digital output to constantly
change by a few LSBs. If the auxiliary ADC is used to control
volume, this constant change causes small gain fluctuations.
To avoid this, add a low-pass filter or hysteresis to the auxiliary
ADC signal path by enabling either function in the auxiliary
ADC and power control register (2082), as described in Table 56.
The filter is enabled by default when the auxiliary ADC is
enabled. When data is read from the auxiliary ADC registers,
two bytes (12 bits of data, plus zero-padded LSBs) are available
because of this filtering.
AUX ADC
INPUT PIN
20kΩ
S2
1.8pF
S1
Multipurpose Pin
MP0
MP1
MP2
MP3
MP4
MP5
MP6
MP7
MP8
MP9
MP10
MP11
Function
N/A
N/A
ADC1
ADC2
N/A
N/A
N/A
N/A
ADC3
ADC0
N/A
N/A
GENERAL-PURPOSE INPUT/OUTPUT PINS
The general-purpose input/output (GPIO) pins can be used as
either inputs or outputs. These pins are readable and can be set
either through the control interface or directly by the SigmaDSP
core. When set as inputs, these pins can be used with push-button
switches or rotary encoders to control DSP program settings.
Digital outputs can be used to drive LEDs or external logic to
indicate the status of internal signals and control other devices.
Examples of this use include indicating signal overload, signal
present, and button press confirmation.
When set as an output, each pin can typically drive 2 mA. This
is enough current to directly drive some high efficiency LEDs.
Standard LEDs require about 20 mA of current and can be
driven from a GPIO output with an external transistor or buffer.
Because of issues that could arise from simultaneously driving
or sinking a large current on many pins, care should be taken in
the application design to avoid connecting high efficiency LEDs
directly to many or all of the MPx pins. If many LEDs are required,
use an external driver.
When the GPIO pins are set as open-collector outputs, they
should be pulled up to a maximum voltage of 3.3 V (the voltage
on IOVDD).
05798-017
10kΩ
Table 63. Multipurpose Pin Auxiliary ADC Mapping
Figure 30. Auxiliary ADC Input Circuit
SERIAL DATA INPUT/OUTPUT PORTS
Figure 30 shows the input circuit for the auxiliary ADC. Switch S1
enables the auxiliary ADC and is set by Bit 15 of the auxiliary
ADC enable register. The sampling switch, S2, operates at the
audio sampling frequency (fS).
The auxiliary ADC data registers can be written to directly after
AACW in the DSP core control register has been set. In this
mode, the voltages on the analog inputs are not written into the
registers, but rather the data in the registers is written from the
control port.
PVDD supplies the 3.3 V power for the auxiliary ADC analog
input. The digital core of the auxiliary ADC is powered with the
1.8 V DVDD signal.
The flexible serial data input and output ports of the ADAU1702
can be set to accept or transmit data in 2-channel format or in an
8-channel TDM stream. Data is processed in twos complement,
MSB-first format. The left-channel data field always precedes
the right-channel data field in the 2-channel streams. In TDM
mode, Slot 0 to Slot 3 are in the first half of the audio frame, and
Slot 4 to Slot 7 are in the second half of the frame. TDM mode
allows fewer multipurpose pins to be used, freeing more pins
for other functions. The serial modes are set in the serial output
and serial input control registers.
The serial data clocks need to be synchronous with the ADAU1702
master clock input.
Rev. 0 | Page 44 of 52
ADAU1702
The input control register allows control of clock polarity and
data input modes. The valid data formats are I2S, left-justified,
right-justified (24-/20-/18-/16-bit), and 8-channel TDM. In all
modes except for the right-justified modes, the serial port accepts
an arbitrary number of bits up to a limit of 24. Extra bits do not
cause an error, but they are truncated internally. Proper operation
of the right-justified modes requires that there be exactly 64 BCLKs
per audio frame. The TDM data is input on SDATA_IN0. The
LRCLK in TDM mode can be input to the ADAU1702 either as
a 50/50 duty cycle clock or as a bit-wide pulse.
In TDM mode, the ADAU1702 can be a master for 48 kHz and
96 kHz data, but not for 192 kHz data. Table 64 lists the modes
in which the serial output port can function.
Table 64. Serial Output Port Master/Slave Mode Capabilities
fS
48 kHz
96 kHz
192 kHz
2-Channel Modes
(I2S, Left-Justified,
Right-Justified)
Master and slave
Master and slave
Master and slave
8-Channel TDM
Master and slave
Master and slave
Slave only
the input port function only as slaves, whereas the output port
clocks can be set to function as either masters or slaves. The
INPUT_LRCLK (MP4) and INPUT_BCLK (MP5) pins are
used to clock the SDATA_INx (MP0 to MP3) signals, and the
OUTPUT_LRCLK (MP10) and OUTPUT_BCLK (MP11) pins
are used to clock the SDATA_OUTx (MP6 to MP9) signals.
If an external ADC is connected as a slave to the ADAU1702,
use both the input and output port clocks. The OUTPUT_LRCLK
(MP10) and OUTPUT_BCLK (MP11) pins must be set into
master mode and connected externally to the INPUT_LRCLK
(MP4) and INPUT_BCLK (MP5) pins as well as to the external
ADC clock input pins. The data is output from the external
ADC into the SigmaDSP on one of the four SDATA_INx pins
(MP0 to MP3).
Connections to an external DAC are handled exclusively with the
output port pins. The OUTPUT_LRCLK and OUTPUT_BCLK
pins can be set to function as either masters or slaves, and the
SDATA_OUTx pins are used to output data from the SigmaDSP
to the external DAC.
Table 66 describes the proper configurations for standard audio
data formats.
The output control registers allow the user to control clock
polarities, clock frequencies, clock types, and data format. In all
modes except for the right-justified modes (MSB delayed by 8,
12, or 16 bits), the serial port accepts an arbitrary number of
bits up to a limit of 24. Extra bits do not cause an error, but are
truncated internally. Proper operation of the right-justified
modes requires the LSB to align with the edge of the LRCLK.
The default settings of all serial port control registers
correspond to 2-channel I2S mode. All register settings apply to
both master and slave modes unless otherwise noted.
The function of each multipurpose pin in serial data port mode
is shown in Table 65. Pin MP0 to Pin MP5 support digital data
input to the ADAU1702, and Pin MP6 to Pin MP11 handle digital
data output from the DSP. The configuration of the serial data
input port is set in the serial input control register (Table 51), and
the configuration of the corresponding output port is controlled
with the serial output control register (Table 49). The clocks of
Table 65. Multipurpose Pin Serial Data Port Functions
Multipurpose Pin
MP0
MP1
MP2
MP3
MP4
MP5
MP6
MP7
MP8
MP9
MP10
MP11
Function
SDATA_IN0/TDM_IN
SDATA_IN1
SDATA_IN2
SDATA_IN3
INPUT_LRCLK (slave only)
INPUT_BCLK (slave only)
SDATA_OUT0/TDM_OUT
SDATA_OUT1
SDATA_OUT2
SDATA_OUT3
OUTPUT_LRCLK (master or slave)
OUTPUT_BCLK (master or slave)
Table 66. Data Format Configurations
Format
I2S (Figure 31)
LRCLK Polarity
Frame begins on falling edge
LRCLK
Type
Clock
BCLK Polarity
Data changes on falling edge
Left-Justified (Figure 32)
Right-Justified (Figure 33)
Frame begins on rising edge
Frame begins on rising edge
Clock
Clock
Data changes on falling edge
Data changes on falling edge
TDM with Clock (Figure 34)
Frame begins on falling edge
Clock
Data changes on falling edge
TDM with Pulse (Figure 35)
Frame begins on rising edge
Pulse
Data changes on falling edge
Rev. 0 | Page 45 of 52
MSB Position
Delayed from LRCLK edge
by 1 BCLK
Aligned with LRCLK edge
Delayed from LRCLK edge
by 8, 12, or 16 BCLKs
Delayed from start of word clock
by 1 BCLK
Delayed from start of word clock
by 1 BCLK
ADAU1702
LEFT CHANNEL
LRCLK
RIGHT CHANNEL
BCLK
LSB
MSB
LSB
MSB
05798-018
SDATA
1/FS
2
Figure 31. I S Mode—16 Bits to 24 Bits per Channel
MSB
LSB
MSB
LSB
05798-019
SDATA
RIGHT CHANNEL
LEFT CHANNEL
LRCLK
BCLK
1/FS
Figure 32. Left-Justified Mode—16 Bits to 24 Bits per Channel
RIGHT CHANNEL
SDATA
MSB
LSB
MSB
LSB
05798-020
LEFT CHANNEL
LRCLK
BCLK
1/FS
Figure 33. Right-Justified Mode—16 Bits to 24 Bits per Channel
LRCLK
256 BCLKs
BCLK
DATA
32 BCLKs
SLOT 1
SLOT 2
SLOT 3
SLOT 4
SLOT 5
SLOT 6
SLOT 7
SLOT 8
LRCLK
MSB–1
MSB–2
05798-021
BCLK
MSB
DATA
Figure 34. TDM Mode
LRCLK
BCLK
MSB TDM
MSB TDM
CH
0
8TH
CH
SLOT 0
SLOT 1
SLOT 2
SLOT 3
SLOT 4
SLOT 5
SLOT 6
SLOT 7
05798-022
SDATA
32
BCLKs
Figure 35. TDM Mode with Pulse Word Clock
Rev. 0 | Page 46 of 52
ADAU1702
LAYOUT RECOMMENDATIONS
PARTS PLACEMENT
The ADC input voltage-to-current resistors and the ADC current
set resistor should be placed as close as possible to the 2, 3, and
4 input pins.
All 100 nF bypass capacitors, which are recommended for every
analog, digital, and PLL power/ground pair, should be placed as
close as possible to the ADAU1702. The 3.3 V and 1.8 V signals
on the board should also each be bypassed with a single bulk
capacitor (10 μF to 47 μF).
All traces in the crystal oscillator circuit (Figure 14) should be
kept as short as possible to minimize stray capacitance. In addition,
avoid long board traces connected to any of these components
because such traces may affect crystal start-up and operation.
GROUNDING
A single ground plane should be used in the application layout.
Components in an analog signal path should be placed away
from digital signals.
Rev. 0 | Page 47 of 52
ADAU1702
TYPICAL APPLICATION SCHEMATICS
05798-023
SELF-BOOT MODE
Figure 36. Self-Boot Mode Schematic
Rev. 0 | Page 48 of 52
ADAU1702
05798-024
I2C CONTROL
Figure 37. I2C Control Schematic
Rev. 0 | Page 49 of 52
ADAU1702
05798-025
SPI CONTROL
Figure 38. SPI Control Schematic
Rev. 0 | Page 50 of 52
ADAU1702
OUTLINE DIMENSIONS
9.20
9.00 SQ
8.80
1.60
MAX
37
48
36
1
PIN 1
0.15
0.05
7.20
7.00 SQ
6.80
TOP VIEW
1.45
1.40
1.35
0.20
0.09
7°
3.5°
0°
0.08
COPLANARITY
SEATING
PLANE
VIEW A
(PINS DOWN)
25
12
13
VIEW A
0.50
BSC
LEAD PITCH
ROTATED 90° CCW
COMPLIANT TO JEDEC STANDARDS MS-026-BBC
24
0.27
0.22
0.17
051706-A
0.75
0.60
0.45
Figure 39. 48-Lead Low-Profile Quad Flat Package [LQFP]
(ST-48)
Dimensions shown in millimeters
ORDERING GUIDE
Model
ADAU1702JSTZ 1
ADAU1702JSTZ-RL1
EVAL-ADAU1702EB
1
Temperature Range
0°C to 70°C
0°C to 70°C
Package Description
48-Lead LQFP
48-Lead LQFP, 13 in Reel
Evaluation Board
Z = Pb-free part.
Rev. 0 | Page 51 of 52
Package Option
ST-48
ST-48
ADAU1702
NOTES
©2006 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05798-0-10/06(0)
Rev. 0 | Page 52 of 52