NJU26904 Digital Audio Delay ■ General Description ■Package The NJU26904 offers digital audio delay. The NJU26904 has internal delay memory. Delay function can adjust output time of a six-channel signal. This delay functions are suitable for delay time adjustment such as Audio products and time alignment such as Car Audio. ■ FEATURES NJU26904V-C2 • 6-channel Digital Audio Delay Delay Time 84msec for monaural channel, 42msec for stereo channel at Fs=96kHz Delay Time 169msec for monaural channel, 85msec for stereo channel at Fs=48kHz Delay Time 254msec for monaural channel, 127msec for stereo channel at Fs=32kHz • Delay data width is 24 bits. Digital Audio Format: I2S 24bit, Left-Justified, Right-Justified, BCK: 32/64fs • Adjustable Delay Time with 1sample units for 8,121 samples at maximum. • Selectable input sources for each channel output freely. • To make long delay time, the NJU26904 can be connected serially. • Non-Audio Format is possible. - Hardware • Maximum System Clock Frequency : 12.288MHz Max. built-in PLL Circuit • Digital Audio Interface : 3 Input ports / 3 Output ports • Digital Audio Format : I2S 24bit, Left- Justified, Right-Justified, BCK : 32/64fs • Master / Slave Mode - Master Mode, MCK : 384fs @32kHz, 256fs @48kHz • Host Interface : I2C bus (Fast-mode/400kbps) • Power Supply : 3.3V • Input terminal : 5V Input tolerant • Package : SSOP24-C2 (Pb-Free) Ver.2008-12-02 -1- NJU26904 ■ Function Block Diagram SCL SDI0-2 I2C INTERFACE SDA SDO0-2 HOST CONTROL BCK RESETb SERIAL AUDIO INTERFACE MCK CLKOUT TIMING GENERATOR / PLL CLK LR ADDRESS GENERATION UNIT SLAVEb Internal Pow er (1.8V) Built-in LDO WDC Delay RAM VREGO External Low -ESR Capacitors Required GPIO INTERFACE AD2 AD1 1.8V level terminal Fig. 1 NJU26904 Block Diagram -2- Ver.2008-12-02 NJU26904 ■ DSP Block Diagram SDI0_L SDI0_R SDI1_L SDI1_R SDI2_L SDI2_R SDO0_L SDI0_L SDI0_R SDI1_L SDI1_R SDI2_L SDI2_R SDO0_R SDI0_L SDI0_R SDI1_L SDI1_R SDI2_L SDI2_R SDI0_L SDI0_R SDI1_L SDI1_R SDI2_L SDI2_R Delay Memory SDO1_L Free dividing SDO1_R SDI0_L SDI0_R SDI1_L SDI1_R SDI2_L SDI2_R SDO2_L SDI0_L SDI0_R SDI1_L SDI1_R SDI2_L SDI2_R SDO2_R Fig. 2 NJU26904 Function Diagram Ver.2008-12-02 -3- NJU26904 ■ Pin Configuration RESETb 1 24 TEST LR 2 23 SCL BCK 3 22 SDA SDI2 4 21 SDO2 SDI1 5 20 SDO1 19 SDO0 18 WDC NJU26904 SDI0 6 MCK 7 VDD 8 17 AD2 VSS 9 16 AD1 STBYb 10 15 SLAVEb VSS 11 14 CLK VREGO 12 13 CLKOUT SSOP24-C2 Fig. 3 NJU26904 Pin Configuration ■ Pin Description Table 1 Pin Description No. Symbol I/O Description No. Symbol I/O Description 1 RESETb I RESET (active Low) 13 CLKOUT O OSC Output 2 LR I/O LR Clock 14 CLK I OSC Clock Input 3 BCK I/O Bit Clock 15 SLAVEb I Slave select 4 SDI2 I Audio Data Input 2 L/R 16 AD1 I I2C Address 1 5 SDI1 I Audio Data Input 1 L/R 17 AD2 I I2C Address 2 6 SDI0 I Audio Data Input 0 L/R 18 WDC OD Clock for Watch Dog Timer 7 MCK I/O Master Clock 19 SDO0 O Audio Data Output 0 L/R 8 VDD Power Supply +3.3V 20 SDO1 O Audio Data Output 1 L/R 9 VSS GND 21 SDO2 O Audio Data Output 2 L/R 10 STBYb I For TEST (Connected to VDD) 22 SDA OD I2C I/O 11 VSS GND 23 SCL I I2C Clock 12 VREGO PI Built-in Power Supply Bypass 24 TEST I For TEST(Connected to VSS) * I : Input, O : Output, I/O: Bi-directional, OD: Open-Drain I/O, PI: Power Supply Bypass AD1 (No.16) pin and AD2 (No.17) pin are input pins. WDC (No.18) pin is open-drain pin with pull-up resistance. However, these pins operate as bi-directional pins. No.11pin and No.12pin connect with VDD or VSS through 3.3kΩ resistance. No.18pin do not connect or connect with VDD through 3.3kΩ resistance when unused. VREGO (No.12) pin is a built-in power supply bypass pin. Connect low-ESR capacitor of 4.7uF and 0.01uF in parallel between VSS (No.11) pin. A built-in power supply is used only for NJU26904 operation. Be not short-circuited of this pin. Do not take out the current, and connect other power supplies. -4- Ver.2008-12-02 NJU26904 ■ Absolute Maximum Ratings ( VSS=0V=GND, Ta=25°°C ) Rating Units Table 2 Absolute Maximum Ratings Parameter Symbol Supply Voltage * Supply Voltage Bypass * VDD VREGO -0.3 to 4.2 -0.3 to 2.3 In Vx(IN) I/O, OD Vx(I/O) ,Vx(OD) -0.3 to 5.5 (VDD ≥ 3.0V) -0.3 to 4.2 (VDD < 3.0V) Out Vx(OUT) -0.3 to 4.2 CLK Vx(CLK) CLKOUT Vx(CLKOUT) Pin Voltage * V V V -0.3 to 4.2 Power Dissipation Operating Voltage Storage Temperature 565 mW PD -40 to 85 TOPR °C TSTR -40 to 125 °C * The LSI must be used inside of the “Absolute maximum ratings”. Otherwise, a stress may cause permanent damage to the LSI. * VDD : 8 pin * VREGO : 12 pin * Vx(IN) : 1, 4, 5, 6, 10, 15, 23, 24 pin * Vx(OD) : 22 pin * Vx(I/O) : 2, 3, 7, 16, 17, 18 pin * Vx(OUT) : 19, 20, 21 pin * Vx(CLK) : 14 pin * Vx(CLKOUT) : 13 pin ■ Terminal equivalent circuit diagram VDD VDD(1.8V) CLK CLKOUT VDD VDD(1.8V) PAD RPD VSS V SS Input, I/O (Input part) (1 to 7, 22, 23pin) (With RPU: 18pin With RPD: 15, 16, 17, 24pin) CLK/CLKOUT (13, 14pin) VDD RPU VDD PAD PAD Output Disable VSS Output, I/O (Output part) (2, 3, 7, 16, 17, 19, 20, 21pin ) ( Open Drain Output with RPU : 18pin) ( Open Drain Output: 22pin ) VSS STBYb (10pin) Fig.4 NJU26904 Terminal equivalent circuit diagram Ver.2008-12-02 -5- NJU26904 ■ Electric Characteristics ( VDD=3.3V, fOSC=12.288MHz, Ta=25°°C ) Table 3 Electric Characteristics Parameter Operating Voltage Symbol *1 Test Condition Min. Typ. Max. Units 3.0 3.3 3.6 V - 20 35 mA VDD VDD pin Operating Current IDD At no load High Level Input Voltage VIH VDD x 0.7 - VDD Low Level Input Voltage VIL 0 - VDD x 0.3 High Level Output Voltage Low Level Output Voltage *3 Clock Frequency Clock Jitter *5 Clock Duty Cycle *4 V VOH (IOH= -1mA) VDD x 0.8 - VDD VOL (IOL= 1mA) 0 - VDD x 0.2 -10 - 10 -120 - 10 IIN(PD) -10 - 120 fOSC 10 12.288 13 MHz 0 - 3.0 ns 45 50 55 % IIN Leakage Current *2 IIN(PU) fJIT(CC) rEC VIN = VSS to VDD CLK, MCK *6 µA *1 Supply voltage must be within recommended operating voltage. Furthermore supplying power voltage must be linear, quick and smooth to prevent abnormal operation. Once the power supply is set up, supply voltage must be kept within the operating voltage range. After setting up the power supply, even if the supply voltage dropped off and recovered to normal range, reset function and the all following operations can not be guaranteed. After using this DSP, power supply must be dropped to VSS level. *2 *3 *4 *5 *6 Input pin, Output pin and Open-Drain input/output pin are +5.0V tolerant except CLK input pin. Except No.18pin: WDC (Open-Drain output) and No.22: SDA (Open-Drain input/output). I IN(PU) : 18pin, I IN(PD) : 15, 16, 17, 24 pin Clock Jitter shows Cycle-to-cycle period jitter (JEDEC JESD65). Provide clock frequency for fOSC spec. NJU26904 needs clock frequency 12.288MHz when sampling rate is 48kHz. -6- Ver.2008-12-02 NJU26904 1. Power Supply, Input/Output terminal, Clock, Reset 1.1 Power Supply The NJU26904 has a power supply VDD. To setup good power supply condition, the decoupling capacitors should be implemented at the all power supply terminals. The NJU26904 include a built-in power supply (LDO) for internal logic. A built-in power supply generates 1.8V (-10% to +10%). VREGO (No.12) pin is a built-in power supply bypass pin. Connect low-ESR capacitor of 4.7uF and 0.01uF in parallel between VSS (No.11) pin. A built-in power supply is used only for NJU26904 operation. Be not short-circuited of this pin. Do not take out the current, and connect other power supplies. 1.2 Input/Output terminal It restricts, when the input terminals (AD1, AD2, RESETb, SDI0, SDI1, SDI2, STBYb, SLAVEb, SCL, TEST pins), the input/output terminals (LR, BCK, MCK pins) and the bi-directional Open-drain terminal (SDA pin) of NJU26904, and VDD are supplied on regular voltage (VDD=3.3V), and it becomes +5V Input tolerant. 1.3 Clock The NJU26904 CLK pin requires the system clock. The system clock is usually 12.288MHz into CLK pin. It is possible to be generated the system clock by connecting a crystal oscillator between CLK and CLKOUT. CLK/CLKOUT pins are not 5V tolerant, so check the voltage level of these pins. When SLAVEb pin is fixed on Low level, NJU26904 supplies the system clock from MCK pin. Fix the clock input pin not used to Low level because either the CLK pin or the MCK pin is supplied in NJU26904. The frequency divider for Master mode matched to the clock 256 times of Fs is installed in NJU26904. When clock except 256 times of Fs is used by Master mode, be careful to use because a dividing frequency of Master mode changes. Please check enough and decide parameter. Ver.2008-12-02 -7- NJU26904 1.4 Reset To initialize the NJU26904, RESETb pin should be set Low level during some period. After some period of Low level, RESETb pin should be High level. This procedure starts the initialization of the NJU26904. After the power supply and the oscillation of the NJU26904 becomes stable, RESETb pin must be kept Low-level more than tRESETb period. (Fig.5) After RESETb pin level goes to "High" (after reset release), a setup of the internal hardware of a Serial Host Interface completes NJU26904 within 10msec. Then, it will be in the state which can communicate. VDD tVREGO VREGO CLK OSC unstable OSC stable tRESETb RESETb Fig.5 Reset Timing Table 4 Reset Time Symbol Time tVREGO ≥ 10msec tRESETb ≥ 1.0msec Note : Don’t stop the supply of a clock while operating. NJU26904 installs PLL circuit internally. If the supply of a clock is stopped, PLL circuit cannot be sent a clock to the inside and NJU26904 does not operate normally. If supply of a clock is stopped or the NJU26904 is reset again, putting a normal clock into CLK terminal, the period RESETb terminal of tRESETb is kept “Low” level.(Table 4) Next, the NJU26904 is reset. Then redo from initial setting. -8- Ver.2008-12-02 NJU26904 2. Digital Audio Clock Digital audio data needs to synchronize and transmit between digital audio systems. The NJU26904 - master mode / slave mode - both of the modes are supported. - In Master mode; Use the clock of BCKO and a LRO pin output clock for digital audio data transfer. - In Slave mode; The clock output from a master device is needed for the input terminal of BCKI and LRI. A device in the system generates the transmitted clock become a standard. The other devices are set according to the transmitted clock. The device generating transmitted clock is called Master Device. The device according to the transmitted clock is called Slave Device. NJU26904 usually operates Slave Device. However, NJU26904 becomes Master Device in case of SLAVEb set the High level and NJU26904 is set Master mode by firmware command. In Slave mode, clock inputted to the BCK pin and the LR pin is used to digital audio signal transmission. In Master mode, clock outputted to the BCK pin and the LR pin is used to digital audio signal transmission. 2.1 Audio Clock Three kinds of clocks are needed for digital audio data transfer. (1) LR clock (LR) is needed by serial-data transmission. It is the same as the sampling frequency of a digital audio signal. (2) Bit clock (BCK) is needed by serial-data transmission. It becomes the multiple of LR clock. (3) Master clock (MCK) is needed by A/D, D/A converter, etc. It becomes the multiple of LR clock. It is not related to serial audio data transmission. In SLAVEb is High level, the MCK pin becomes buffer output pin for input clock to the CLK pin after NJU26904 resets. The MCK output is able to be stopped by firmware command. In SLAVEb is Low level, MCK pin becomes system clock input pin. It is not insure to change the logical switch of SLAVEb pin during operating. If it is necessary to change SLAVEb pin setting, reset NJU26904 every time. Table 5 SLAVEb, BCK, LR, MCK SLAVEb and firmware LR pin setting SLAVEb=”Low” LR clock input Firmware: each DSP slave operating SLAVEb=”High” Firmware: Slave SLAVEb=”High” Firmware: Master LR clock output DSP Master operating BCK pin Bit clock input DSP slave operating Bit clock output DSP Master operating MCK pin NJU26904 operating clock input (MCK or CLK) Master clock output (Buffer of CLK) In NJU26904 is used by 256 times of Maximum sampling frequency, NJU26904 is able to output LR clock of same sampling rate and two-third times of sampling rate, and output BCK clock of 32 times sampling rate and 64 times sampling rate in Master mode. Ver.2008-12-02 -9- NJU26904 Table 6 Input clock (In Slave mode at fosc=12.288MHz) Multiple Mode Clock Signal 32kHz 44.1kHz 48kHz 96kHz Frequency LR 1fs 32kHz 44.1kHz 48kHz 96kHz BCK (32fs) 32fs 1.024MHz 1.4112MHz 1.536MHz 3.072MHz BCK (64fs) 64fs 2.048MHz 2.822MHz 3.072MHz 6.144MHz DSP MCK Slave Input terminal: Clock is generated by MCK or CLK (SLAVEb=”L”) MCK Buffer output of 12.288MHz (SLAVEb=”H”) CLK Table 7 Output clock (In Master mode at fosc=12.288MHz) Output from BCK/LR Multiple Mode Clock Signal Frequency 32kHz 48kHz 64kHz LR 1fs 32kHz 48kHz 64kHz DSP BCK (32fs) 32fs 1.024MHz 1.536MHz 2.048MHz Master BCK (64fs) 64fs 2.048MHz 3.072MHz 4.096MHz MCK 12.288MHz - 10 - 192kHz 192kHz 6.144MHz 12.288MHz 96kHz 96kHz 3.072MHz 6.144MHz Ver.2008-12-02 NJU26904 3. Digital Audio Interface 3.1 Digital Audio Data Format The NJU26904 can use three kinds of formats hereafter as industry-standard digital audio data format. : MSB is put on the 2nd bit of LR clock change rate.(1 bit is delayed to left stuffing) (1) I2S (2) Left-Justified : LR clock -- MSB is placed for changing. (3) Right-Justified: LSB is placed just before LR clock change rate. The main differences among three kinds of formats are in the position relation between LR clock (LR) and an audio data (SDI, SDO). - In every format: : a left channel is transmitted previously. - In Right/Left-Justified : LR clock ='High' shows a left channel. - I2S : LR clock=”Low” shows a left channel. - The Bit clock BCK is used as a shift clock of transmission data. The number of clocks more than the number of sum total transmission bits of a L/R channel is needed at least. - One cycle of LR clock is one sample of a stereo audio data. The frequency of LR clock becomes equal to a sample rate (Fs). - The NJU26904 supports serial data format which includes 32(32fs) or 64(64fs) BCK clocks. This serial data format is applied to both MASTER and SLAVE mode. 3.2 Serial Audio Data Input/output The NJU26904 audio interface includes 3 data input lines: SDI0, SDI1 and SDI2 (Table 8). 3 data output lines: SDO0, SDO1 and SDO2. (Table 9). Table 8 Serial Audio Input Pin Description Pin No. Symbol Description 6 SDI0 Audio Data Input 0 L/R 5 SDI1 Audio Data Input 1 L/R 4 SDI2 Audio Data Input 2 L/R Table 9 Serial Audio Output Pin Description Pin No. Symbol Description 19 SDO0 Audio Data Output 0 L/R 20 SDO1 Audio Data Output 1 L/R 21 SDO2 Audio Data Output 2 L/R The input terminal is selectable for the output terminal freely. Refer to Figure 2 NJU26904 Function Diagram. Ver.2008-12-02 - 11 - NJU26904 The NJU26904 can use three kinds of formats hereafter as industry-standard digital audio data format; (1) I2S (2) Left-Justified (3) Right-Justified and 24 / 20 / 18 / 16bits data length. (Fig.6-1 to Fig6-12) An audio interface input and output data format become the same data format. Left Channel LRI, LRO Right Channel BCKI, BCKO MSB LSB MSB 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 SDI, SDO LSB 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks 32 Clocks Fig.6-1 I2S Data Format 64fs, 24bit Data LRI, LRO Left Channel Right Channel BCKI, BCKO MSB LSB MSB 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 SDI, SDO LSB 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks 23 32 Clocks Fig.6-2 Left-Justified Data Format 64fs, 24bit Data Left Channel LRI, LRO Right Channel BCKI, BCKO MSB SDI, SDO 2 1 0 LSB 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 MSB LSB 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks 32 Clocks Fig.6-3 Right-Justified Data Format 64fs, 24bit Data Left Channel LRI, LRO Right Channel BCKI, BCKO MSB LSB MSB 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 SDI, SDO LSB 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks 32 Clocks 2 Fig.6-4 I S Data Format 64fs, 20bit Data Left Channel LRI, LRO Right Channel BCKI, BCKO MSB SDI, SDO LSB 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 MSB LSB 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks 19 32 Clocks Fig.6-5 Left-Justified Data Format 64fs, 20bit Data Left Channel LRI, LRO Right Channel BCKI, BCKO MSB SDI, SDO 2 1 0 LSB 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks MSB LSB 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks Fig.6-6 Right-Justified Data Format 64fs, 20bit Data - 12 - Ver.2008-12-02 NJU26904 Left Channel LRI, LRO Right Channel BCKI, BCKO MSB LSB MSB 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 SDI, SDO LSB 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks 32 Clocks Fig.6-7 I2S Data Format 64fs, 18bit Data LRI, LRO Left Channel Right Channel BCKI, BCKO MSB SDI, SDO LSB MSB 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 LSB 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks 17 32 Clocks Fig.6-8 Left-Justified Data Format 64fs, 18bit Data Left Channel LRI, LRO Right Channel BCKI, BCKO MSB SDI, SDO 2 1 0 LSB MSB 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 LSB 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 32 Clocks 32 Clocks Fig.6-9 Right-Justified Data Format 64fs, 18bit Data Left Channel LRI, LRO Right Channel BCKI, BCKO MSB SDI, SDO LSB MSB LSB 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 16 Clocks 16 Clocks 2 Fig.6-10 I S Data Format 32fs, 16bit Data LRI, LRO Left Channel Right Channel BCKI, BCKO MSB SDI, SDO LSB MSB LSB 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 16 Clocks 16 Clocks Fig.6-11 Left-Justified Data Format 32fs, 16bit Data Left Channel LRI, LRO Right Channel BCKI, BCKO MSB SDI, SDO LSB MSB LSB 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 16 Clocks 16 Clocks Fig.6-12 Right-Justified Data Format 32fs, 16bit Data Ver.2008-12-02 - 13 - NJU26904 3.3 Serial Audio Input Timing Table 10 Serial Audio Input Timing Parameters Parameter Symbol Test Condition ( VDD=3.3V, fosc=12.288MHz, Ta=25°°C ) Min Typ. Max Units BCK Frequency * BCK Period * Low Pulse Width High Pulse Width BCK to LR Time ** fBCKI - - 13 MHz tSIL tSIH tSLI 35 35 15 - - ns - - ns LR to BCK Time ** tLSI 15 - - ns Data Setup Time tDS 15 - - ns Data Hold Time tDH 15 - - ns * It is the regulation of absolute maximum ratings. Maximum frequency of BCK is limited. ** It is the regulation in slave mode. LR tSIH tSIL tSLI tDS tDH tLSI BCK SDI Fig.7 Serial Audio Input Timing Table 11 Serial Audio Output Timing Parameters Parameter Symbol Test Condition BCK to LR Time * tSLO Data Output Delay tDOD CL=25pF Min ( VDD=3.3V, Ta=25°°C ) Typ. Max Units -15 - 15 ns - - 15 ns * It is the regulation in Master mode. LR tSLO BCK tDOD SDO Fig.8 Serial Audio Input Timing - 14 - Ver.2008-12-02 NJU26904 ■ Host Interface The NJU26904 can be controlled via Serial Host Interface (SHI) using I2C bus. Data transfers are in 8 bit packets (1 byte) when using either format. Refer to serial Host Interface Pin Description.(Table 12) Table 12 Serial Host Interface Pin Description Symbol Pin No. I2C bus Format (I2C bus) 16 AD1 I2C bus address Bit 1 17 AD2 I2C bus address Bit 2 Serial Data Input/Output 22 SDA (Open Drain Input/Output) 23 SCL Serial Clock Note : SDA pin (No.22) is a bi-directional open drain terminal. This pin requires a pull-up resister. AD1 (No.16) pin and AD2 (No.17) pin are input pins with pull-down. AD1 (No.16) pin and AD2 (No.17) pin are connected with VDD or VSS through 3.3kΩ resistance. When NJU26904 is stopped by power supply VDD, SDA pin and SCL pin become Hi-Z. But these pins are not 5V tolerant when VDD stops. ■ I2C bus I2C bus interface transfers data to the SDA pin and clocks data to the SCL pin. SDA pin is a bi-directional open drain and requires a pull-up resister. AD1 pin and AD2 pin are used to configure the seven-bit SLAVE address of the serial host interface. (Table 13) This offers additional flexibility to a system design by four different SLAVE addresses of the NJU26904. An address can be arbitrarily set up by the AD1 pin and AD2 pin. The I2C address of AD1 and AD2 pin are decided by connection of AD1 pin and AD2 pin. Table 13 I2C bus SLAVE Address bit7 0 0 0 0 bit6 0 0 0 0 Start bit bit5 1 1 1 1 bit4 1 1 1 1 bit3 1 1 1 1 Slave Address ( 7bit ) AD2 bit2 0 0 1 1 AD1 bit1 0 1 0 1 R/W bit R/W bit0 RW ACK * SLAVE address is 0 when AD1 and AD2 are “Low”. SLAVE address is 1 when AD1 and AD2 are “High”. * SLAVE address is 0 when R/W is “W”. SLAVE address is 1 when R/W is “R”. Ver.2008-12-02 - 15 - NJU26904 ( VDD=3.3V, fOSC=12.288MHz, Ta=25°°C ) Table 14 I2C bus Interface Timing Parameters Parameter Symbol Min Max Units fSCL tHD:STA tLOW tHIGH tSU:STA tHD:DAT tSU:DAT tR tF tSU:STO tBUF 0 0.6 1.3 0.6 0.6 0 250 0.6 1.3 400 0.9 1000 300 - kHz µs µs µs µs µs ns ns ns µs µs SCL Clock Frequency Start Condition Hold Time SCL “Low” Duration SCL “High” Duration Start Condition Setup Time Data Hole Time *1 Data Setup Time Rising Time Falling Time Stop Condition Setup Time Bus Release Time *2 SDA tR tBUF tF tHD:STA SCL tHD:STA t LOW P tHD:DAT tHIGH tSU:STA tSU:DAT tSU:STO Sr S P 2 Fig.9 I C bus Timing Note : *1 tHD:DAT: Keep data 100ns hold time to avoid indefinite state by SCL falling edge. *2 This item shows the interface specification. The interval of a continuous command is specified separately. - 16 - Ver.2008-12-02 NJU26904 ■ WatchDog Clock The NJU26904 outputs clock pulse through WDC (No.18) pin during normal operation. The NJU26904 generates a clock pulse through the WDC terminal after resetting the NJU26904. The WDC clock is useful to check the status of the NJU26904 operation. For example, a microcomputer monitors the WDC clock and checks the status of the NJU26904. When the WDC clock pulse is lost or not normal clock cycle, the NJU26904 does not operate correctly. Then reset the NJU26904 and set up the NJU26904 again. Watchdog clock output cycle is set by a command. Note: If input and output of an audio signal stop and an audio interface stops, WDC can’t output. That is because it has controlled based on the signal of an audio interface. ■ NJU26904 Command Table Table 15 NJU26904 Command No. 1 2 3 Command System State Config ( MCK, BCK, CLK, Data width etc. ) I/O Config ( SDO Source Select, Setup SDO ) Delay Setup ( 8,121 samples, 1 sample step, Setup SDO ) No. Command 8 SDO Input Select Config Read 9 SDO Delay Setup Read 10 Watchdog Setup Read 4 Watchdog Setup 11 Version Number 5 Re-Initialize Command 12 Software Reset 6 Task State Read 13 Auto Buffer Clear Disable / enable 7 System State Config Read 14 Start / Stop . Ver.2008-12-02 - 17 - NJU26904 ■ Package SSOP24-C2, Pb-Free [CAUTION] The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. - 18 - Ver.2008-12-02