Texas Instruments TAS3002 manual 6 I2C Serial Control Interface, Introduction, 6.2 I2C Protocol

Page 29
6 I2C Serial Control Interface

6 I2C Serial Control Interface

6.1 Introduction

Control parameters for the TAS3002 device can be loaded from an I2C serial EEPROM by using the TAS3002 master interface mode. If no EEPROM is found, the TAS3002 device becomes a slave device and loads from another I2C master interface. Information loaded into the TAS3002 registers is defined in Appendix A.

The I2C bus uses terminals 16 (SDA for data) and 15 (SCL for clock) to communicate between integrated circuits in a system. These devices can be addressed by sending a unique 7-bit slave address plus R/W bit (1 byte). All compatible devices share the same terminals via a bidirectional bus using a wired-AND connection. An external pullup resistor must be used to set the high level on the bus. The TAS3002 device operates in standard mode up to 100 kbps with as many devices on the bus as desired up to the capacitance load limit of 400 pF.

Furthermore, the TAS3002 device supports a subset of the SMBus protocol. When it is attached to the SMBus, then byte, word, and block transfers are supported. The SMBus NAK function is not supported and care must be taken with the sequence of the instructions sent to the TAS3002 device.

Additionally, the TAS3002 device operates in either master or slave mode; therefore, at least one device connected to the I2C bus must operate in master mode.

6.2 I2C Protocol

The bus standard uses transitions on SDA while the clock is high to indicate start and stop conditions. A high-to-low transition on SDA indicates a start and a low-to-high transition indicates a stop. Normal data bit transitions must occur within the low time of the clock period. Figure 6−1 shows these conditions. These start and stop conditions for the I2C bus are required by standard protocol to be generated by the master. The master must also generate the 7-bit slave address and the read/write (R/W) bit to open communication with another device and then wait for an acknowledge condition. The slave holds SDA low during acknowledge clock period to indicate an acknowledgment. When this occurs, the master transmits the next byte of the sequence.

After each 8-bit word, an acknowledgment must be transmitted by the receiving device. There is no limit on the number of bytes that can be transmitted between start and stop conditions. When the last word transfers, the master generates a stop condition to release the bus. Figure 6−1 shows a generic data transfer sequence.

SDA

SCL

 

 

 

 

7-Bit

 

 

 

 

 

R/

A

 

8-Bit Register Data

A

 

8-Bit Register Data

A

 

8-Bit Register Data

A

 

 

 

 

 

Slave Address

W

 

for Address (N)

 

 

 

for Address (N+1)

 

for Address (N+2)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

6

 

 

 

 

1

0

 

 

7

 

6

 

 

 

 

1

 

0

 

 

7

 

6

 

 

 

 

1

0

 

 

7

 

6

 

 

 

 

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Start

Stop

Figure 6−1. Typical I 2C Data Transfer Sequence

6−1

Page 28 Page 30
Image 29
Page 28 Page 30
Contents TAS3002 Data ManualDigital Audio Processor With Codec 2001IMPORTANT NOTICE 1.1 Description 1.2Features1 Introduction 1.3Functional Block Diagram Figure 1−1. TAS3002 Block Diagram 1.5 Terminal Functions 1.4 Terminal AssignmentsFigure 1−2. TAS3002 Terminal Assignments Table 1−1. TAS3002 Terminal FunctionsTable 1−1. TAS3002 Terminal Functions Continued Page Table 2−1. Serial Interface Options 2 Audio Data Formats2.1 Serial Interface Formats 2.2 Digital Output Modes … … … …… … … … … … … …Figure 2−2. I 2S Serial-InterfaceFormat 2.2.2I2S Serial-InterfaceFormat… … … … … … … …… … … … 2.2.3MSB-Left-Justified, Serial-InterfaceFormat… … … … … … … …PARAMETER 2.3 Switching CharacteristicsUNIT tcSCLK SCLK LRCLK tdSDOUT SDOUT1 SDOUT2 SDOUT0Page 3.1 Analog Input 3 Analog Input/Output3.2 Analog Output 3.2.1Direct Analog OutputFigure 3−3. Analog Output With External Amplifier 3.2.2Analog Output With GainFigure 3−2. VCOM Decoupling Network Figure 3−4. TAS3002 Reference Voltage Filter 3.2.3Reference Voltage FilterTAS3002 Page 4 Audio Control/Enhancement Functions 4.1 Soft Volume Update4.2 Software Soft Mute 4.3 Input Mixer ControlFigure 4−1. TAS3002 Mixer Function 4.4 Mono Mixer Control4.5 Treble Control Figure 4−2. De-EmphasisMode Frequency Response 4.6 Bass Control4.7 De-EmphasisMode DM Table 4−1. Analog Control Register Description 4.8 Analog Control Register 40h4.9.1Loudness Biquads 4.9 Dynamic Loudness Contour4.9.2Loudness Gain 4.9.3Loudness Contour Operation4.11 AllPass Function 4.10 Dynamic Range Compression/Expansion DRCE4.13 Main Control Register 2 43h 4.12 Main Control Register 1 01hTable 4−2. Main Control Register 1 Description Table 4−3. Main Control Register 2 DescriptionPage 5 Filter Processor Figure 5−1. Biquad Cascade Configuration5.1 Biquad Block 5.1.1Filter CoefficientsPage 6.1 Introduction 6 I2C Serial Control Interface6.2 I2C Protocol Figure 6−1. Typical I 2C Data Transfer Sequence6.3.1Write Cycle Example 6.3 OperationTable 6−1. I 2C Protocol Definitions Table 6−2. I 2C Address Byte Table6.3.3I2C Wait States 6.3.2TAS3002 I2C Readback Example6.4.1Block Write Protocol 6.4 SMBus Operation6.4.2Write Byte Protocol Table 6−3. I 2C Wait States6.4.4TAS3002 SMBus Readback 6.4.3Wait StatesPage 7.2.1Power-UpSequence 7.2 Power-Up/Power-DownReset7.2.2Reset 7 Microcontroller OperationFigure 7−1. TAS3002 Reset Circuit 7.2.3Reset Circuit7.2.4Fast Load Mode TAS30027.2.5Codec Reset 7.3 Power-DownModeFigure 7−2. Power-DownTiming Sequence 7.3.1Power-DownTiming Sequence7.4 Test Mode 7.5 Internal InterfaceTable 7−1. GPI Terminal Programming 7.6.2GPI ArchitectureRestore Volume and MCR Figure 7−3. Internal Interface Flow ChartStart Power Up Initialize Default EEPROM Slave Write GPI Power DownTable 7−2. 512-ByteEEPROM Memory Map 2.0 Channels 7.7 External EEPROM Memory MapsBYTE NUMBER ADDRESSFUNCTION TAS3002NUMBER TAS3002 ADDRESSFUNCTION CATEGORYNUMBER TAS3002 ADDRESSFUNCTION CATEGORY8.2 Recommended Operating Conditions 8 Electrical CharacteristicsStatic Digital Specifications 8.4 ADC Digital Filter Figure 8−1. ADC Digital Filter Characteristics8.5 Analog-to-DigitalConverter Figure 8−4. ADC High-PassFilter Characteristics8.7 DAC Interpolation Filter 8.6 Input Multiplexer8.9 DAC Output Performance Data 8.8 Digital-to-AnalogConverterFigure 8−7. I 2C Bus Timing 8.10 I2C Serial Port Timing CharacteristicsFigure 9−1. Stereo Application 9 System DiagramsTAS3002 ClockTAS3002 TAS3001Figure 9−2. TAS3002 Device, 2.1 Channels PLASTIC QUAD FLATPACK 10 Mechanical InformationPFB S-PQFP-G48 10−2
Top Page Image Contents