WM8776-EV2M...WM8776-EV2M w Rev 1.3, March 2005 4 EVALUATION BOARD OPERATION POWER SUPPLIES Using appropriate power leads with 4mm connectors, power supplies should be connected as

WM8776-EV2M

Evaluation Board User Handbook Rev 1.3

WM8776-EV2M

w Rev 1.3, March 2005

2

TABLE OF CONTENTS

TABLE OF CONTENTS .................................................................................. 2

INTRODUCTION ............................................................................................. 3

GETTING STARTED....................................................................................... 3 EVALUATION KIT CHECKLIST .............................................................................3 CUSTOMER REQUIREMENTS..............................................................................3

EVALUATION BOARD OPERATION.............................................................. 4 POWER SUPPLIES ...............................................................................................4 BOARD FUNCTIONALITY .....................................................................................4 BOARD INPUT.......................................................................................................5 BOARD OUTPUT ...................................................................................................5 INTERFACES.........................................................................................................6 HEADERS ..............................................................................................................6 LINKS, JUMPERS AND SWITCHES......................................................................7

WM8776 OPERATION .................................................................................... 9 SOFTWARE CONTROL.........................................................................................9

SERIAL INTERFACE SOFTWARE DESCRIPTION...................................... 11 SOFTWARE DOWNLOAD................................................................................... 11 SOFTWARE INSTALLATION............................................................................... 11 SOFTWARE OPERATION ................................................................................... 11 POWER DOWN AND INTERFACE CONTROL.................................................... 17 ADC, DAC AND OUTPUT CONTROL.................................................................. 18 VOLUME CONTROL............................................................................................ 19 LIMITER/ALC CONTROL..................................................................................... 20 SCHEMATIC LAYOUT ......................................................................................... 21 WM8776-EV2B PCB LAYOUT ............................................................................. 29

WM8776-EV2B BILL OF MATERIAL............................................................ 33

APPENDIX .................................................................................................... 35

DAC AND ADC ALTERNATIVE AUDIO INTERFACE CONFIGURATION ... 35 MASTER/SLAVE MODE....................................................................................... 35

EXTERNAL DSP CONNECTION TO THE WM8776-EV1B .......................... 37

AUDIO INTERFACE CONNECTIONS.................................................................. 37 SOFTWARE INTERFACE.................................................................................... 39 CONNECTION DIAGRAMS.................................................................................. 40

ADDITIONAL WM8776-EV1B SETUP RECOMMENDATIONS.................... 42

ADC TO DAC LOOPBACK ........................................................................... 42

EVALUATION SUPPORT ............................................................................. 44

IMPORTANT NOTICE ................................................................................... 45 ADDRESS: ........................................................................................................... 45

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INTRODUCTION

The WM8776 is a high performance stereo audio CODEC for surround sound processing applications for home hi-fi, DVD-RW and other audio visual equipment.

This evaluation platform and documentation should be used in conjunction with the latest version of the WM8776 datasheet. The datasheet gives device functionality information as well as timing and data format requirements.

This evaluation platform has been designed to allow the user ease of use and give optimum performance in device measurement as well as providing the user with the ability to listen to the excellent audio quality offered by the WM8776.

GETTING STARTED

EVALUATION KIT CHECKLIST

The following items are available from Wolfson:

• WM8776-EV1B Evaluation Board (order from Wolfson)

• WM8776-EV1S .exe file for control software (download from http://www.wolfsonmicro.com/)

• WM8776-EV1M User Handbook (download from http://www.wolfsonmicro.com/)

CUSTOMER REQUIREMENTS

Minimum customer requirements are:

• D.C. Power supply of +5V

• D.C. Power supply of +2.7V to +5.5V

• D.C. Power supply of +/-12.0V

• PC and printer cable (for software control)

Minimum PC spec requirements are:

• Win95/98/NT/2000/XP

• 486 Processor

DAC Signal Path Requires:

• Digital coaxial or optical data source

• 1 set of active stereo speakers and/or 1 set of headphones

ADC Signal Path Requires:

• Analogue coaxial signal source

• Digital coaxial or optical data receiving unit

Analogue Signal Path Requires:

• Analogue coaxial signal source

• 1 set of active stereo speakers and/or 1 set of headphones

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EVALUATION BOARD OPERATION

POWER SUPPLIES

Using appropriate power leads with 4mm connectors, power supplies should be connected as described in Table 1.

REF-DES SOCKET NAME SUPPLY

J1 +5V +5V

J2 DVDD +2.7V to +3.6V

J54 AVDD +2.7V to +5.5V

J10 HPVDD +2.7V to +5.5V

J8 +12V +12V

J7 -12V -12V

J2 GND 0V

J70 GND 0V

Table 1 Power Supply Connections

The GND and GND connections may be connected to a common GND on the supply with no reduction in performance.

To reduce the supply connections that need to be attached to the EVB, site L10 is populated with a 0R resistor shorting AVDD and HPVDD. In this configuration it is recommended that the supply only be attached to AVDD. If separate supplies are required the 0R resistor should be removed from site L10.

Note: Refer to WM8776 datasheet for limitations on individual supply voltages.

Important: Exceeding the recommended maximum voltage can damage EVB components. Under voltage may cause improper operation of some or all of the EVB components.

BOARD FUNCTIONALITY

There are three options for inputting digital data into the WM8776 evaluation board. There is a coaxial input (J5) via a standard phono connector or an optical input (U1) via a standard optical receiver module. A direct digital input is also available via one side of a 2x8 pin header (H1).

The analogue input signals are applied to the evaluation board via double phono connectors J4 (AIN_LEFT/RIGHT1), J13 (AIN_LEFT/RIGHT2), J14 (AIN_LEFT/RIGHT3), J20 (AIN_LEFT/RIGHT4), J21 (AIN_LEFT/RIGHT5). A analogue AUX signal input can also be applied to the evaluation board via a double phono connector J24 (AUX_LEFT/RIGHT).

There are two options for outputting digital data from the WM8776 evaluation board. There is a coaxial output (J18) via a standard phono connector. The digital signals may also be accessed via one side of a 2x8 pin header (H2).

The line analogue outputs of the board are via phono connectors J19 (VOUTL) and J23 (VOUTR). The headphone analogue outputs of the board are via a 3.5mm jack socket J46 (HEADPHONE_OUT).

All WM8776 device pins are accessible for easy measurement via the 2x6 pin headers (H3, H4, H5 and H6) running up each side of the device.

Level-shift IC’s (U5 and U8) are used to shift the fixed +5V digital input from the CS8427 (U4) down to the same level as DVDD and vice-versa.

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BOARD INPUT

REF-DES SOCKET NAME SIGNAL J5 SPDIF_IN Digital (AES/EBU, UEC958,

S/PDIF, EIAJ CP340/1201) signal.

U1 DIGITAL_OPTICAL INPUT

Digital (AES/EBU, UEC958,S/PDIF, EIAJ CP340/1201) optical signal.

Table 2 Digital Inputs

REF-DES SOCKET NAME SIGNAL J4 AIN_L/R_1 Analogue Input signal

J13 AIN_L/R_2 Analogue Input signal




J24 AUX_L/R Analogue Input signal

Analogue signals applied to these connectors are AC coupled before being input to the WM8776.

Table 3 Analogue Inputs

Note: When used in Slave Mode, an SPDIF signal must still be applied to phono connector J5. This input signal is used to allow correct operation of the CS8427 as well as being used to generate the MCLK for the WM8776.

BOARD OUTPUT

REF-DES SOCKET NAME SIGNAL J18 SPDIF_OUT Digital (AES/EBU, UEC958,

S/PDIF, EIAJ CP340/1201) signal.

Table 4 Digital Output

REF-DES SOCKET NAME SIGNAL J46 HEADPHONE OUT Headphone Output

J23 VOUT_R Line Output

J19 VOUT_L Line Output

Table 5 Analogue Outputs

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INTERFACES

H1

J2

SW2

SW6

J10J1 J70

0

1123456

OPEN

H3

J7

J16

1

J15

1

LNK41

J32

1

LNK1

1

J22

1

1

LNK6J11

KEY

123

13579111315

246810121416

12

1357911

24681012

1357

2468

J8

J54J3

H2

J12

1

J25

1

J9

1

J331

J17

1

J30

1

J29

1

H5

H4

H612

1

Figure 1 Interfaces

HEADERS

H1 SIGNAL H2 SIGNAL

1/2 DIN 16/15 GND

3/4 GND 14/13 ADCMCLK

5/6 DACLRC 12/11 GND

7/8 GND 10/9 DIN

9/10 DACBCLK 8/7 GND

11/12 GND 6/5 ADCBCLK

13/14 DACMCLK 4/3 GND

15/16 GND 2/1 ADCLRC

LNK1 SIGNAL LNK4 SIGNAL

1 ZFLAGL 1 ZFLAGR

2 AGND 2 AGND

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H3 WM8776 PIN NAME H5 WM8776 PIN NAME

1 1 AIN2L 1 25 NC

2 2 AIN1R 2 26 VOUTL

3 3 AIN1L 3 27 VOUTR

4 4 DACBCLK 4 28 VMIDDAC

5 5 DACMCLK 5 29 DACREFN

6 6 DIN 6 30 DACREFP

7 7 DACLRC 7 31 AUXR

8 8 ZFLAGR 8 32 AUXL

9 9 ZFLAGL 9 33 VMIDADC

10 10 ADCBCLK 10 34 ADCREFGND

11 11 ADCMCLK 11 35 ADCREFP

12 12 DOUT 12 36 AVDD

H4 WM8776 PIN NAME H6 WM8776 PIN NAME

1 13 ADCLRC 1 37 AGND

2 14 DGND 2 38 AINVGR

3 15 DVDD 3 39 AINOPR

4 16 MODE 4 40 AINVGL

5 17 CE 5 41 AINOPL

6 18 DI 6 42 AIN5R

7 19 CL 7 43 AIN5L

8 20 HPOUTL 8 44 AIN4R

9 21 HPGND 9 45 AIN4L

10 22 HPVDD 10 46 AIN3R

11 23 HPOUTR 11 47 AIN3L

12 24 NC 12 48 AIN2R

Table 6 Headers

LINKS, JUMPERS AND SWITCHES LINKS AND JUMPERS

LINK/JUMPER STATUS

DESCRIPTION

J12 OPEN

SHORT

DAC Slave Mode (Level shift direction) [default setting]

DAC Master Mode

J15 (BCLK) OPEN

SHORT

Master mode

Slave mode (Ties ADCBCLK to DACBCLK) [default setting]

J16 (LRC) OPEN

SHORT

Master mode

Slave mode (Ties ADCLRC to DACLRC) [default setting]

J25 OPEN

SHORT

ADC Slave Mode (Level shift direction) [default setting]

ADC Master Mode

J9 (MCLK) OPEN

SHORT

Master mode

Slave mode (Ties DACMCLK to ADCMCLK) [default setting]

J32, J33, J22, J17 OPEN

SHORT

OUT Signals are AC coupled [default setting]

OUT Signals are not AC coupled

J29 OPEN

SHORT

AINR input gain set to 1

AINR input gain set to 0.5 [default setting]

J30 OPEN

SHORT

AINL input gain set to 1

AINL input gain set to 0.5 [default setting]

Table 7 Links

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SWITCHES SWITCH STATUS DESCRIPTION

SW1 After an input data format change has been made using SW2, the CS8427 will only latch the new settings after SW1 has been pressed and released.

SW2

(DATA FORMAT)

1 2 3 4 5 6 DATA FORMAT

1 0 0 1 0 0 I2S Compatible [default setting]

1 0 0 0 0 1 24-bit Right Justified

1 0 0 0 0 0 Left Justified

J11

(Software Control)

ON

OFF

2-wire Control Mode

3-wire (SPI) Control Mode [default setting]

LNK6

(5V tolerant supply control)

Pins 1 and 2 SHORT

Pins 2 and 3 SHORT

Centre Position

DVDD Supply for S/W and mode control [default setting]

+5v Supply for S/W and mode control

No Supply for S/W and mode control

Table 8 Switches

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WM8776 OPERATION

SOFTWARE CONTROL

There are two possible serial software control modes that may be selected to operate the WM8776. The standard SPI user interface is a 3-wire solution with the second option being a 2-wire solution.

3-WIRE MODE

To operate the WM8776 in SPI (3-wire) mode, jumper switch J11 must be set to the OFF position, selection of 3 wire mode will be indicated by D1 being OFF. The 3-wire serial interface then becomes active on pins 17(CE), 18(DI) and 19(CL). The serial interface on the board can be connected to a PC via the printer port or any other standard parallel port. The port used can be selected through the software provided. The software supplied with this kit gives the user access to all the possible features provided by the WM8776. The 3-wire latch, data and clock lines may also be connected to the board via the test points TP6 (CE), TP18 (DI) and TP4 (CL).

Please refer to the WM8776 datasheet for full details of the serial interface timing and all register features.

B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0DI

CL

CE

control register address control register data bits

latch

Figure 2 3-Wire Serial Interface

2-WIRE MODE

To operate the WM8776 in 2-wire mode, jumper switch J11 must be set to the ON position, selection of 2 wire mode will be indicated by D1 being ON. The 2-wire serial interface becomes active on pins 18(DI) and 19(CL). The serial interface on the board can be connected to a PC via the printer port or any other standard parallel port. Note: a bi-directional parallel port is required for 2-wire operation1. The 2-wire data and clock lines may also be connected to the board via the test points TP18 (DI) and TP4 (CL).

When used in 2-wire mode, the WM8776 has two possible addresses (0011010 [0x34h] or 0011011 [0x36h]) that are selectable by pulling CSB low or high. If connecting a probe to the Test Points it must be noted that the CSB line is pulled high on the WM8776 evaluation board selecting address 0011011. CSB must be pulled low or driven low through the software writes if address 0011010 is used (as is done in the WM8776-EV1S software provided).

Figure 3 2-Wire Serial Interface

Note: 1If the 2-wire mode is not reporting as expected then the most likely cause is that the parallel port being used is not

bi-directional. In most PC’s, the parallel port can be configured in the BIOS settings during initial power up.

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REGISTER ADDRESS (Bit 15 – 9) Bit[8] Bit[7] Bit[6] Bit[5] Bit[4] Bit[3] Bit[2] Bit[1] Bit[0]

R0 (00h) 0 UPDATE LINMUTE HPLA[6:0]

R1 (01h) 1 UPDATE RINMUTE HPRA[6:0]

R2 (02h) 10 UPDATEA LO1ZC HPMASTA[6:0]

R3 (03h) 11 UPDATED LDA[7:0]

R4 (04h) 100 UPDATED RDA[7:0]

R5 (05h) 101 UPDATED MASTDA[7:0]

R6 (06h) 110 0 0 0 0 0 0 0 PHASE[1:0]

R7 (07h) 111 0 PL[3:0] TOD IZD ATC DZCEN

R8 (08h) 1000 0 0 0 0 0 0 0 0 DMUTE

R9 (09h) 1001 0 0 0 0 0 0 DZFM[1:0] DEEMPH

R10 (0Ah) 1010 0 0 0 DACWL[1:0] DACBCP DACLRP DACFMT[1:0]

R11 (0Bh) 1011 ADCHPD 0 0 ADCWL[1:0] ADCBCP ADCLRP ADCFMT[1:0]

R12 (0Ch) 1100 ADCMS DACMS DACRATE[2:0] ADCOSR ADCRATE[2:0]

R13 (0Dh) 1101 0 0 AINPD 0 0 HPPD DACPD ADCPD PDWN

R14 (0Eh) 1110 ZCLA LAG[7:0]

R15 (0Fh) 1111 ZCRA RAG[7:0]

R16 (10h) 10000 LCSEL[1:0] MAXGAIN[2:0] LCT[3:0]

R17 (11h) 10001 LCEN ALCZC 0 0 0 HLD[3:0]

R18 (12h) 10010 FDECAY DCY[3:0] ATK[3:0]

R19 (13h) 10011 0 0 0 0 NGTH[2:0] NGG NGAT

R20 (14h) 10100 CHGPERZC[1:0] TRANWIN[2:0] MAXATTEN[3:0]

R21 (15h) 10101 LRBOTH MUTELA MUTERA 0 AMX[4:0]

R22 (16h) 10110 0 0 0 MX[2:0]

R23 (17h) 10111 writing 000000000 to this register resets all registers to their default state

Table 9 Mapping of Program Registers

Please refer to the WM8776 datasheet for full details of the serial interface timing and all register features.

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SERIAL INTERFACE SOFTWARE DESCRIPTION

The following section will detail the downloading and installation of evaluation software and also the operation of the software and the functionality of each control button. Details the main panel, hidden panels and details on the hardware setup required to use the main functional buttons “DAC Setup”, “ADC Setup” AND “Line Setup” will be provided.

SOFTWARE DOWNLOAD

The current evaluation board software should be downloaded from the Wolfson website [www.wolfsonmicro.com].

From the homepage it is recommended that you do a search for ‘WM8776’ and select the ‘more’ button located under the ‘EVALUATION BOARDS’ heading. Select ‘DOWNLOAD’ from the right hand side of the screen under the ‘SOFTWARE’ heading. Once you have accepted the licence agreement you can select the WM8776_EV1S_REVx.x.ZIP link and download to your hard drive.

SOFTWARE INSTALLATION

Once the .zip file has been downloaded, to install the software:

• Open the .zip file

• Double click on the setup.exe file.

• Follow the on-screen installation instructions and save to the desired location.

The software can then be opened by either running the extracted WM8776_EV1_REV1.exe file from the saved location. Alternatively select: Start > Programs > WM8776-EV1S Revx.x > WM8776-EV1S.

SOFTWARE OPERATION

Due to the many features offered by the WM8776 the software has been split into 4 different panels. This eases the complexity of the software making each panel less busy, the panels have also been grouped so that it makes it simple to control each section of the device.

The main menu panel shown in Figure 4 is used to call up the other panels as well as offering a number of pull-down menus.

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Figure 4 Software Menu Panel

SUBMIT ALL

The ‘Submit All’ button will submit the current panel settings, within each of the four main panels to every register of the WM8776. This means changes within a number of different panels can be made and then submitted together.

WM8776 RESET

The ‘Reset’ button writes to the reset register (R23) but does not reset the control panel values. If the previous values are to be resubmitted then the ‘Submit All’ button should be pressed.

RESET SOFTWARE PANEL SETTINGS

If the user would like to start afresh then the ‘Reset Software Panel Settings’ button should also be pressed. Pressing this button does not write to the device, it only resets the panel settings to their default state.

WOLFSON LOGO

Left clicking on the Wolfson logo will open the PCs default web browser and go top the Wolfson Microelectronics website (‘www.wolfsonmicro.com’).

On the main panel there are three buttons, “DAC Setup”, “ADC Setup” and “Line Setup” which have been provided as a quick start approach. Pressing either of these buttons will power up the DAC, ADC or Line signal paths in a known state as described in the following pages.

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Important: It must be noted that the CS8427 SPDIF decoder IC will only work at a rate of 256fs. This will limit the sample rates that may be set using the WM8776 unless an external source is used supplying signals directly to the relevant pins of header H1 or taking the signals from the relevant pins of header H2.

DAC SUBMIT SETUP

By pressing the ‘DAC Setup’ button, the software writes to the device setting the SPDIF_In through DAC to the VOUTL/R and Headphone outputs; active in 24-bit, I2S input data format. Table 6 lists the required board settings to allow this signal path to become active. This is to ease the initial use of the WM8776 hardware and software until the user becomes familiar with both device and software operation.

PA

RA

LLE

L P

OR

T

123456

OPEN

AGND

AVDD+2.7V

to+5.5VDGND

DVDD+2.7V

to+3.6V

VO

UT

L

VO

UT

R

OPT_IN

SPDIF_IN

SPDIF_OUT

H1

J2

SW2

SW6

J10J1 J70

H3

J7

J16

1

J15

1

LNK4

1

J32

1

LNK1

1

J22

1

1

LNK6J11

J8

J54J3

H2

J12

1

J25

1

J9

1

J33

1

J17

1J30

1

J29

1

H5

H4

H6

1

+5v

+12v -12v

Headphone Out

0

1

AIN_L/R_1

AIN_L/R_2

AIN_L/R_3

AIN_L/R_4

AIN_L/R_5

AUX_L/R

Figure 5 Recommended DAC Setup

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LINKS AND JUMPERS

LINK/JUMPER STATUS

DESCRIPTION

H1 Fit jumpers (1,2) (5,6) (9,10) (13,14)

DAC clocks and data input

H2 No jumpers in place ADC clocks and data output

J12 OPEN DAC Slave mode

J15 (BCLK) OPEN Separate BCLK (To DAC only)

J16 (LRC) OPEN Separate LRC (To DAC only)

J25 OPEN ADC Slave mode

J9 (MCLK) OPEN Separate MCLK (To DAC only)

SW2 1 2 3 4 5 6 DATA FORMAT

1 0 0 1 0 0 I2S Compatible

LNK6 Pins 1 and 2 SHORT

DVDD Supply for S/W and mode control

J11 OFF 3-wire (SPI) Control Mode

J32, J33, J22, J17 OPEN OUT Signals are AC coupled

J29 OPEN AINR input gain set to 1

J30 OPEN AINL input gain set to 1

Table 10 DAC Setup Jumper Settings (Slave Mode)

ADC SUBMIT SETUP

By pressing the ‘ADC Setup’ button, the software writes to the device setting the AIN_L/R_1 through ADC to SPDIF_Out path active. As with the DAC setup described previously, this is to ease the initial use of the WM8776 until the user becomes familiar with both device and software operation. It should be noted that the SPDIF_In connection is still required to provide the necessary clocks to the WM8776 in this mode.

PA

RA

LLE

L P

OR

T

123456

OPEN

AGND

AVDD+2.7V

to+5.5VDGND

DVDD+2.7V

to+3.6V

VO

UT

L

VO

UT

R

OPT_IN

SPDIF_IN

SPDIF_OUT

H1

J2

SW2

SW6

J10J1 J70

H3

J7

J16

1

J15

1

LNK4

1

J32

1

LNK1

1

J22

1

1

LNK6J11

J8

J54J3

H2

J12

1

J25

1

J9

1

J33

1

J17

1

J30

1

J29

1

H5

H4

H6

1

+5v

Headphone Out

0

1

The SPDIF input isrequired to provideclocks for theWM8750 audiointerface.

AIN_L/R_1

AIN_L/R_2

AIN_L/R_3

AIN_L/R_4

AIN_L/R_5

AUX_L/R

Figure 6 Recommended ADC Setup

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LINKS AND JUMPERS

LINK/JUMPER STATUS

DESCRIPTION

H1 Fit jumpers (5,6) (9,10) (13,14)

DAC clocks

H2 Fit jumpers (1,2) (5,6) (9,10) (13,14)

ADC clocks and data output from WM8776


J15 (BCLK) SHORT Link BCLK (DAC BCLK to ADC)

J16 (LRC) SHORT Link LRC (DAC LRC to ADC)


J9 (MCLK) SHORT Link MCLK ((DAC MCLK to ADC)







J29 SHORT AINR input gain set to 0.5

J30 SHORT AINL input gain set to 0.5

Table 11 ADC Setup Jumper Setup (Slave Mode)

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LINE SUBMIT SETUP

By pressing the ‘Line Setup’ button, the software writes to the device setting the AIN_L/R_1 through the analogue path to the VOUTL/R and Headphone outputs. As with the previous configurations, this is to ease the initial use of the WM8776 until the user becomes familiar with both device and software operation.

Note: The WM8776 does not require an MCLK to operate in this mode. If the ADC or DAC are used then the MCLK would be required.

PA

RA

LLE

L P

OR

T

123456

OPEN

AGND

AVDD+2.7V

to+5.5VDGND

DVDD+2.7V

to+3.6V

VO

UT

L

VO

UT

R

OPT_IN

SPDIF_IN

SPDIF_OUT

H1

J2

SW2

SW6

J10J1 J70

H3

J7

J16

1

J151

LNK4

1

J32

1

LNK1

1

J22

1

1

LNK6J11

J8

J54J3

H2

J12

1

J25

1

J9

1

J33

1

J17

1

J30

1

J29

1

H5

H4

H6

1

+5v

+12v -12v

Headphone Out

0

1

AIN_L/R_1

AIN_L/R_2

AIN_L/R_3

AIN_L/R_4

AIN_L/R_5

AUX_L/R

Figure 7 Recommended Line Setup

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LINKS AND JUMPERS

LINK/JUMPER STATUS

DESCRIPTION

H1 No jumpers in place DAC clocks

H2 No jumpers in place ADC clocks


J15 (BCLK) OPEN Separate BCLK

J16 (LRC) OPEN Separate LRC


J9 (MCLK) OPEN Separate MCLK









Table 12 Line Setup Jumper Setup (Slave Mode)

POWER DOWN AND INTERFACE CONTROL

Figure 8 Power and Interface Control

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The Power Down and Interface Control panel is used to enable/disable the various sections of the WM8776. It is also used to individually set the audio interface to the required data format for both the ADC and DAC. Pressing the ‘Power Submit’ button will cause the settings shown on this panel to be written to the WM8776. A full device register write is not sent using the ‘Power Submit’ button.

ADC, DAC AND OUTPUT CONTROL

Figure 9 DAC and ADC Control

The ADC, DAC and Output Control panel is used to control the ADC, DAC and Output Mixer related features of the WM8776. Pressing the ‘ADC, DAC and Output Submit’ button will cause the settings shown on this panel to be written to the WM8776. A full device register write is not sent using the ‘ADC, DAC and Output Submit’ button.

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VOLUME CONTROL

Figure 10 Volume Control

The Volume Control panel is used to control both analogue (input and Headphone output) and digital volume settings of the WM8776. The volume sliders update in ‘real’ time (i.e. the ‘Volume Submit’ button does not have to be pressed to update the output volume level) but will only have an effect on the output if the Volume Update bits are set. Once changes are made to the Volume Update bits or any other settings excluding the volume sliders, the ‘Volume Submit’ button must be left clicked for the change to take effect. Pressing the ‘Volume Submit’ button will cause the settings shown on this panel to be written to the WM8776. A full device register write is not sent using the ‘Volume Submit’ button.

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LIMITER/ALC CONTROL

Figure 11 Mixer Control

The Limiter/ALC Control panel is used to control the many options offered by the WM8776 for either ALC (Automatic Level Control) or Limiter operation. The default of the WM8776 is for the operation to be disabled, this must firstly be enabled and then the correct limiter or ALC function selected. Controls specific to ALC or limiter are dimmed and not controllable depending on the operation selected. The following control sliders update in ‘real’ time’: Maximum Gain of PGA, Noise Gate Threshold and Limiter Threshold/ALC Target Level (i.e. the ‘Limiter/ALC Submit’ button does not have to be pressed to update these settings). Pressing the ‘Limiter/ALC Submit’ button will cause the settings shown on this panel to be written to the WM8776. A full device register write is not sent using the ‘Limiter/ALC Submit’ button.

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SCHEMATIC LAYOUT

Figure 12 Functional Diagram

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Figure 13 Digital Input

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Figure 14 Software Control

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Figure 15 Level Shift

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Figure 16 Analogue Input and Output Mute

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Figure 17 WM8776

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Figure 18 Analogue Output

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Figure 19 Power

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WM8776-EV2B PCB LAYOUT

Figure 20 Top Layer Silkscreen

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Figure 21 Top Layer

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Figure 22 Bottom Layer

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Figure 23 Bottom Layer Silkscreen

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WM8776-EV2B BILL OF MATERIAL

Description Reference Designator Qty 0.1uF 0805 SMD Ceramic Capacitor 50V X7R C1, C3, C4, C5, C10, C11, C14, C15, C16,

C18, C20, C21, C22, C25, C26, C31, C34, C35, C37, C42, C44, C45, C46, C53, C60, C64, C69, C73, C74, C75, C79, C109

32

220pF 0805 SMD Ceramic Capacitor 50V X7R C12, C13, C17, C51, C67, C68, C71, C72, C76, C80, C81, C82, C83, C84

14

0.01uF 0805 SMD Ceramic Capacitor 50V X7R C2 1

10uF 6.3 Dia 2.5 pitch Oscon Through Hole Cap. 16V 20% C24, C30, C32, C33, C36, C38, C55, C56, C57, C58, C59, C62,C63, C70

14

680pF 0805 SMD Ceramic Capacitor 50V NPO C27, C39 2

1nF 0805 SMD Ceramic Capacitor 50V NPO C28, C40 2

220pF 0805 SMD Ceramic Capacitor 50V NPO C29, C41 2

Unpop 0805 SMD Ceramic Capacitor site C47, C48, C50, C124, C125, C126, C127, C128

8

330uF M Series 10 Dia 5 pitch Through Hole Cap. 35V 20% C49 1

10uF 6.3 Dia 2.5 pitch Oscon Through Hole Cap. 25V 20% C6, C9, C19, C23, C43, C52, C54, C77, C78, C86, C87, C115

12

4.7nF 1206 SMD Ceramic Capacitor 50V X7R C61 1

100uF 8 Dia 3.5 pitch Oscon Through Hole Cap. 10V 20% C65 1

220uF 10 Dia 5 pitch Oscon Through Hole Cap. 10V 20% C7, C66 2

10uF 10V SMD Tantalum Capacitor case A C8 1

HSMY-C670 0805 SMD Chip LED YELLOW D1 1

2x8 2.54mm pitch PCB Pin Header VERTICAL H1, H2 2

2x6 2.54mm pitch PCB Pin Header VERTICAL H3, H4, H5, H6 4

4mm Non-Insulated Panel Socket 16A J1, J2, J3, J7, J8, J10, J54, J70 8

1x2 Jumper Switch 0.1" on-off VERTICAL J11 1

Phono Socket PCB mount BLACK J18 1

Phono Socket PCB mount WHITE J19 1

Phono Socket PCB mount RED J23 1

Phono Socket PCB mount Pair Red/White J4, J13, J14, J20, J21, J24 6

3.5mm Jack Socket 6.5mm Centre Height J46 1

Phono Socket PCB mount YELLOW J5 1

36-way Centronics/IEE488 PCB mountable Connector J6 1

1x2 PCB Pin Header 0.1" VERTICAL J9, J12, J15, J16, J17, J22, J25, J29, J30, J32, J33, LNK1, LNK4

13

47uH 1210 Surface Mount Inductor 'PA series' L1 1

0R 1206 Resistor on 1210 Inductor site L2, L4, L6, L7, L8, L9, L10 7

Unpop 1210 Surface Mount Inductor site L3 1

3.3uH 1210 Surface Mount Inductor '1210A series' L5 1

JSK9-16-G0 PCB 1x3 Jumper Switch 0.1" Center-off VERTICAL

LNK6 1

PCB Mounting Hole 3.2mm Dia. MTH1, MTH2, MTH3, MTH4, MTH5 5

TN0200T N- Channel MOSFET SOT23 Q1, Q2, Q3 3

MMBT3906 PNP Bipolar Transistor SOT23 Q10, Q11 2

FMMT617 NPN Switching Transistor SOT23 Q4, Q5 2

0R 0805 SMD chip resistor 1% 0.1W R1, R27, R34, R38, R54, R60, R67, R73, R74, R76, R77, R125, R126, R127

14

33R 0805 SMD chip resistor 1% 0.1W R10, R11, R12, R13, R14, R15, R16, R17, R37, R48

10

10K 0805 SMD chip resistor 1% 0.1W R18, R28, R29, R39, R41, R49, R50, R51, R52, R56, R57, R58, R59, R61, R62, R63, R64, R65, R68, R70, R72, R86, R87, R88,

24

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34

100K 0805 SMD chip resistor 1% 0.1W R19 1

75R 0805 SMD chip resistor 1% 0.125W R2 1


4K7 0805 SMD chip resistor 1% 0.1W R21, R22, R23, R32, R36, R40, R44 7

1K2 0805 SMD chip resistor 1% 0.1W R24, R25, R26, R47 4

Unpopulated 0805 resistor site R3, R6, R35, R46, R66, R123, R124, R128, R129, R130, R131, R132

12

1K8 0805 SMD chip resistor 1% 0.1W R30, R42 2

7K5 0805 SMD chip resistor 1% 0.125W R31, R43 2

49R9 0805 SMD chip resistor 1% 0.125W R33, R45 2

5k1 0805 SMD chip resistor 1% 0.125W R4,R75, R78, R85 4




47k 1206 SMD chip 4 resistor array 5% 0.063W R7, R8, R9 3

Slotted Panhead Screw - M3 thread; 12mm long SC1, SC2, SC3, SC4, SC6 5

Hexagonal brass M3 size spacer 20mm length SPR1, SPR2, SPR3, SPR4, SPR6 5

B3F1000 SPNO PCB mount switch SW1 1

DIL Switch 6-Way Rocker SW2 1

1.32mm PCB Test Terminal BLACK TP1, TP2, TP3, TP5, TP7, TP10, TP14, TP15, TP22, TP27, TP28

11

1.32mm PCB Test Terminal RED TP4, TP6, TP8, TP9, TP12, TP13, TP16, TP18, TP19, TP20, TP21, TP23, TP24, TP25, TP26

15

TORX176 Digital Audio Optical Receiver U1 1

2:1 Ratio 96KHz SPDIF Digital Audio transformer SOIC (1) U2 1

DS1813 5V active Low Power-On-Reset chip SOT U3 1

CS8427 96KHz Audio Transceiver U4 1

74ALVC164245 16 Bit Dual Supply Bus Transceiver SSO U5, U8 2

WM8776 24-bit; Stereo CODEC with 5 Channel I/P Mux U9 1

Plain M3 size washer WSH1, WSH2, WSH3, WSH4, WSH6 5

Table 13 WM8776-EV1M Bill of Materials

Note: 1 The audio transformer used on this board is manufactured by Scientific Conversion Inc. (www.scientificonversion.com).

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APPENDIX

DAC AND ADC ALTERNATIVE AUDIO INTERFACE CONFIGURATION

The DAC and ADC have separate left/right clocks, bit clocks, master clocks and data I/O’s. The audio interface for each may be configured independently to operate as master or slave. In slave mode ADCLRC, DACLRC, ADCBCLK and DACBCLK are all inputs. In master mode ADCLRC, DACLRC, ADCBCLK and DACBCLK are outputs.

Previous configuration details (ADC, DAC and Line setup) have configured the WM8776 for slave mode. Also the clocks for the audio interface have been generated from the SPDIF crystal and for operation of the ADC common MCLK (fit J9), LRC (fit J16) and BCLK (fit J15) clocks were used. The following information details the configuration of the DAC and ADC for master mode and also the configuration for independent DAC and ADC audio interface.

MASTER/SLAVE MODE

The WM8776-EV1B has the ability to configure the WM8776 for independent DAC and ADC in either master or slave mode. This means that there are four configurable options, the following details the recommended jumper settings for these options.

1. DAC and ADC = Slave. This configuration has been detailed during the software operation explanation.

2. DAC and ADC = Master. The following switch and jumper settings should be made.

LINKS AND JUMPERS

LIINK/JUMPER STATUS

DESCRIPTION

H1 Fit all jumpers DAC clocks to SPDIF crystal

H2 Fit all jumpers ADC clocks to SPDIF crystal

J12 SHORT DAC Master mode (Level shift direction)

J15 (BCLK) OPEN BCLK not linked (DAC BCLK to ADC)

J16 (LRC) OPEN LRC not linked (DAC LRC to ADC)

J25 SHORT ADC Master mode (Level shift direction)

J9 (MCLK) SHORT Link MCLK (DAC MCLK to ADC) Note 1



LNK6 Pins 1 and 2 SHORT DVDD Supply for S/W and mode control





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3. DAC = Master ADC = Slave. The following switch and jumper settings should be made.

LINKS AND JUMPERS

LIINK/JUMPER STATUS

DESCRIPTION



J12 SHORT DAC Master mode (Level shift direction)

J15 (BCLK) SHORT BCLK linked (DAC BCLK to ADC)

J16 (LRC) SHORT LRC linked (DAC LRC to ADC)

J25 OPEN ADC Slave mode (Level shift direction)









4. DAC = Slave ADC = Master. The following switch and jumper settings should be made.

LINKS AND JUMPERS

LIINK/JUMPER STATUS

DESCRIPTION



J12 OPEN DAC Slave mode (Level shift direction)

J15 (BCLK) OPEN BCLK not linked (DAC BCLK to ADC)

J16 (LRC) OPEN LRC not linked (DAC LRC to ADC)

J25 SHORT ADC Master mode (Level shift direction)









Notes:

1. The WM8776-EV1B does not have the functionality to create a separate ADCMCLK. There are two options for the ADCMCLK. One is to use the common DACMCLK by fitting J9, as suggested in table above. The other is to apply an external MCLK to H2/13 and the ground to pin H2/15.

Software configuration of the WM8776 for master and slave mode can be found within the “Power Down and General Audio” panel. It should be noted that the SPDIF crystal (U4) has an MCLK output which is fixed at 256x the sample rate (Fs).

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EXTERNAL DSP CONNECTION TO THE WM8776-EV1B

The WM8776-EV2B evaluation board has been designed to allow it to be easily connected to an external DSP platform with error free operation.

The following information is provided to ease the connection process and ensure that all signals sent and received by the WM8776-EV2B are reliable and at the correct voltage levels.

AUDIO INTERFACE CONNECTIONS

It is recommended that twisted pair (signal twisted with GND) or shielded wires are used to make the audio interface connections between the DSP and WM8776-EV1B platforms. This is to ensure that no interference or noise is picked up by the clocks or data lines, thus reducing performance and reliability.

When the WM8776 is set in Slave Mode (both DAC and ADC), the jumpers on header H1 should be removed, disconnecting the digital input section of the evaluation board. The audio interface timing and data signals from the DSP platform should then be connected as shown in Figure 24. The signals should be connected to H1 and not on the header strip H3 running up each side of the device. Connecting the signals on the output side of the level-shift IC (U5) will cause drive contention between U5 and the DSP and could result in damage to either or both devices. In most cases, the DSP supplies will be set around 3V for low power portable applications. The inputs to the level-shift IC (74ALVC164245) have a TTL threshold (i.e. Logic High = +2V(min); Logic Low = +0.8V(max)) and low input current requirements (i.e. 15uA max) allowing most DSP's to connect directly.

Figure 24 Connections from DSP Platform

The digital inputs to the WM8776 have a CMOS threshold (i.e. Logic High (min) = DBVDDx0.7; Logic Low (max) = DBVDDx0.3). These are met directly by the level shift IC outputs.

The jumpers on H2 should also be removed, disconnecting the digital output section of the WM8776 evaluation board. The DOUT data from the WM8776 should then be connected to the DSP via pin 12 of header strip H3 and the GND connection should be taken from pin 2 of header strip H4.

The ADCDAT signal should be taken direct from the WM8776 digital output (H3) as the output side of the level-shift IC (U5) from the WM8776 is pulled up to +5V which may overdrive and cause damage to the DSP inputs. The digital output levels of the WM8776 are Logic High (min) = DBVDDx0.9; Logic Low (max) = DBVDDx0.1 which should meet the input level requirements of most DSPs running at +3V supplies. If the DSP is running with +5V supplies then the connections to it should be made from the output side of the level-shift IC (U5), connecting the signals as shown in Figure 25.

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Figure 25 Data Connection to the DSP Platform (+5V tolerant input levels)

The connection in Figure 25 is applicable when links J9, J15 and J16 are fitted for common DAC and ADC MCLK, BCLK and LRC clocks. If separate ADC clocks are required then remove links J9, J15 and J16 and connect the separate clocks as shown in Figure 26. The ADC data can then be connected to the point relevant for the DSP power supply, either H2 (5v tolerant) or H3 (direct to device).

H2

GNDADCMCLK

ADCLRC

ADCBCLK

GND

GND

Figure 26 Connections to DSP Platform

When the WM8776 is set to Master mode (DAC and ADC), the jumpers on header H1 should be removed, disconnecting the digital input section of the evaluation board. If an external MCLK signal is being used (i.e. supplied by the DSP) then the DSP platform should be connected as shown in Figure 27 for MCLK and DOUT. The signals should be connected to H1 and not on the header strip H3 running up the side of the device. Connecting the signals on the output side of the level-shift IC (U5) will cause drive contention between U5 and the DSP and could result in damage to either or both devices. In most cases, the DSP supplies will be set around +3V for low power portable applications. The inputs to the level-shift IC (74ALVC164245) have a TTL threshold (i.e. Logic High = +2V(min); Logic Low = +0.8V(max)) and low input current requirements (i.e. 15uA max) allowing most DSPs to connect directly.

Figure 27 Timing Connections from DSP Platform

The digital inputs to the WM8776 have a CMOS threshold (i.e. Logic High (min) = DBVDDx0.7; Logic Low (max) = DBVDDx0.3). These are met directly by the level shift IC outputs.

The DACBCLK AND DACLRC signals can then be connected directly to the device on header H3 pin 4 and pin 7 respectively.

The jumpers on H2 should also be removed, disconnecting the digital output section of the WM8776 evaluation board.

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The DOUT, ADCBCLK and ADCLRC signals should be taken direct from the WM8776 digital output as the output side of the level-shift IC (U4) from the WM8776 is pulled up to +5V which may overdrive and cause damage to the DSP inputs. The digital output levels of the WM8776 are Logic High (min) = DBVDDx0.9; Logic Low (max) = DBVDDx0.1 which should meet the input level requirements of most DSPs running at +3V supplies. If the DSP is running with +5V supplies (and +5V tolerant inputs) then the connections from the WM8776 evaluation board to the DSP should be made from H2 on the output side of the level-shift IC from the WM8776 as shown in Figure 26. The ADCMCLK is only required as an input if a separate MCLK is required. For a common MCLK then by fitting link J9 the DACMCLK will be used.

If the DAC and ADC wish to be configured as separate master and slave then the details for separate operation for either master or slave previous should be followed. Care should be taken when connecting an external DSP to ensure that signal levels and device drive direction (DSP, WM8776 or level shift) are configured correctly to save component damage.

This will ensure that the DSP input level specifications are met.

SOFTWARE INTERFACE

When using the WM8776-EV1B evaluation board with a DSP platform, the registers may be set using the supplied software with a PC and parallel port cable as shown in Figure 28. The example shown is for ADC and DAC in slave mode, interface connections to the board depends on independent configuration for master or slave.

If the DSP is being used to write to the WM8776 registers as well as supplying/receiving the audio interface timing and data signals, then it is recommended that twisted pair or shielded wires are used to connect the DSP platform to the WM8776-EV1B. A direct connection can be made to pin 5 (CE), pin 6 (DI) and pin 7 (CL) of header strip H4 for 3-wire software mode as shown in Figure 29. This is applicable to a DSP with either 3v or 5v tolerant thresholds as the software pins have 5v thresholds.

The same connections apply for controlling the WM8776 via 2-wire software mode (i.e. only pin 6 (DI) and pin 7 (CL) of header strip H4 are used). Pin 5 (CE) can be pulled low on the board if device address 0011010 [0x34h] is required or pulled high address 0011011 [0x36h] is required.

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CONNECTION DIAGRAMS

WM8776-EV1B

H1

SoftwareControl

AudioInterface

DSPPlatform

m

H5

H6

H4

H3

Figure 28 DSP Connection with PC Control using Wolfson Software

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H1

DSPSoftwareControl

AudioInterface

DSPPlatform

WM8776-EV1B

H5

H6

H4

H3

Figure 29 Full DSP Control

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ADDITIONAL WM8776-EV1B SETUP RECOMMENDATIONS

ADC TO DAC LOOPBACK

Setting the WM8776-EV1 into loopback mode allows an analogue signal to be applied to L/RLINE_IN1, passed through the ADC, looped into the DAC and output on the L/ROUT outputs.

PA

RA

LLE

L P

OR

T

123456

OPEN

AGND

AVDD+2.7V

to+5.5VDGND

DVDD+2.7V

to+3.6V

VO

UT

L

VO

UTR

OPT_IN

SPDIF_IN

SPDIF_OUT

H1

J2

SW2

SW6

J10J1 J70

H3

J7

J16

1

J151

LNK4

1

J32

1

LNK1

1

J221

1

LNK6J11

J8

J54J3

H2

J12

1

J25

1

J9

1

J33

1

J171

J30

1

J29

1

H5

H4

H6

1

+5v

+12v -12v

Headphone Out

0

1

AIN_L/R_1

AIN_L/R_2

AIN_L/R_3

AIN_L/R_4

AIN_L/R_5

AUX_L/R

ADCDAT &DACDAT need to

be linked

The SPDIF input isrequired to provideclocks for theWM8750 audiointerface.

Figure 30 Recommended ADC to DAC Loopback Setup

Note: Pin 2 of H1 (DIN) MUST be linked to pin 9 of H2 (DOUT). A digital input must also be applied to U1 or J5 so that the correct clocks are supplied to the WM8776.

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LINKS AND JUMPERS

LINK/JUMPER STATUS

DESCRIPTION

H1 Fit jumpers (5,6) (9,10) (13,14)

DAC clocks

H2 Fit jumpers (1,2) (5,6) (13,14)

ADC clocks


J15 (BCLK) SHORT Link BCLK (DAC BCLK to ADC)

J16 (LRC) SHORT Link LRC (DAC LRC to ADC)


J9 (MCLK) SHORT Link MCLK ((DAC MCLK to ADC)









H1 and H2 Short H1/2 to H2/9 Link DOUT to DIN

Table 14 Loopback Setup Jumper Settings (Slave Mode)

SOFTWARE SETUP

Press the ‘WM8776 Reset’ button. This ensures device is default.

Press the ‘Reset Software Panel Settings’ button. This ensures panel buttons are set to default.

Open the Power Down and General Audio Interface Control panel and set the HPPD bit ‘unchecked’.

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EVALUATION SUPPORT

The aim of this evaluation kit is to help you to become familiar with the functionality and performance of the WM8776 CODEC.

If you require more information or require technical support please contact Wolfson Microelectronics Applications group through the following channels:

Email: [email protected]

Telephone Apps: (+44) 131 272 7070

Fax: (+44) 131 272 7001

Mail: Applications Department at address on last page.

or contact your local Wolfson representative.

Additional information may be made available from time to time on our web site at http://www.wolfsonmicro.com

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IMPORTANT NOTICE

Wolfson Microelectronics plc (WM) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current. All products are sold subject to the WM terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability.

WM warrants performance of its products to the specifications applicable at the time of sale in accordance with WM’s standard warranty. Testing and other quality control techniques are utilised to the extent WM deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements.

In order to minimise risks associated with customer applications, adequate design and operating safeguards must be used by the customer to minimise inherent or procedural hazards. Wolfson products are not authorised for use as critical components in life support devices or systems without the express written approval of an officer of the company. Life support devices or systems are devices or systems that are intended for surgical implant into the body, or support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided, can be reasonably expected to result in a significant injury to the user. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.

WM assumes no liability for applications assistance or customer product design. WM does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of WM covering or relating to any combination, machine, or process in which such products or services might be or are used. WM’s publication of information regarding any third party’s products or services does not constitute WM’s approval, license, warranty or endorsement thereof.

Reproduction of information from the WM web site or datasheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations and notices. Representation or reproduction of this information with alteration voids all warranties provided for an associated WM product or service, is an unfair and deceptive business practice, and WM is not responsible nor liable for any such use.

Resale of WM’s products or services with statements different from or beyond the parameters stated by WM for that product or service voids all express and any implied warranties for the associated WM product or service, is an unfair and deceptive business practice, and WM is not responsible nor liable for any such use.

ADDRESS:

Wolfson Microelectronics plc

Westfield House

26 Westfield Road

Edinburgh

EH11 2QB

United Kingdom

Tel :: +44 (0)131 272 7000

Fax :: +44 (0)131 272 7001

Email :: [email protected]

Documents

WM8776-EV2M...WM8776-EV2M w Rev 1.3, March 2005 4 EVALUATION BOARD OPERATION POWER SUPPLIES Using appropriate power leads with 4mm connectors, power supplies should be connected as