Texas Instruments manual 6.4.3Wait States, 6.4.4TAS3002 SMBus Readback

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6.4.3Wait States

If separate I2C/SMBus commands are sent too frequently, the TAS3002 device can generate a bus wait state. This happens when the device is busy while performing smoothing operations and changing volume, bass, and treble. The wait occurs after the bus acknowledge on the first data byte and can exceed the maximum allowable time allowed according to the SMBus specification (worst case 200 ms).

The following is a possible bus wait state scenario:

CODE	Start	68	84	06	01	00	00	01	00	00	Stop

ACTUAL	Start	68	84	06	01	Wait†	00	00	01	00	00	Stop

†If the master does not recognize bus waiting or if the master times out on a long wait, the master must not send consecutive I2C/SMBus commands without a time interval of 200 ms between transactions.

6.4.4TAS3002 SMBus Readback

The TAS3002 device supports a subset of SMBus readback. When an SMBus read command is sent to the device (LSB = high), it answers with the subaddress and the last six bytes written.

			SMBus	Byte
			Command	Count
			Byte

SENT	Start	69h	xxh	07h		Stop

RECEIVED	Start	07h	aah	ddh		ddh	ddh	ddh	ddh	ddh	Stop

		Byte
		Count
Where:
xxh	= Command byte. It is a don’t care because the response contains only the subaddress and the
	last six bytes of data written to the TAS3002 device.
aah	= The last subaddress accessed in the device
ddh	= Data bytes from the TAS3002 device

NOTE: Use read sequence defined in 6.3.2

6−5

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Contents TAS3002 Data ManualDigital Audio Processor With Codec 2001IMPORTANT NOTICE 1.2Features 1 Introduction1.1 Description 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 2 Audio Data Formats 2.1 Serial Interface FormatsTable 2−1. Serial Interface Options 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 Output3.2.2Analog Output With Gain Figure 3−2. VCOM Decoupling NetworkFigure 3−3. Analog Output With External Amplifier 3.2.3Reference Voltage Filter TAS3002Figure 3−4. TAS3002 Reference Voltage Filter Page 4 Audio Control/Enhancement Functions 4.1 Soft Volume Update4.2 Software Soft Mute 4.3 Input Mixer Control4.4 Mono Mixer Control 4.5 Treble ControlFigure 4−1. TAS3002 Mixer Function 4.6 Bass Control 4.7 De-EmphasisMode DMFigure 4−2. De-EmphasisMode Frequency Response 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 Electrical Characteristics Static Digital Specifications8.2 Recommended Operating Conditions 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 ClockTAS3001 Figure 9−2. TAS3002 Device, 2.1 ChannelsTAS3002 10 Mechanical Information PFB S-PQFP-G48PLASTIC QUAD FLATPACK 10−2