Operational Overview, Input Data Bits | Texas Instruments TLV1562

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Texas Instruments TLV1562 manual Operational Overview, Reference Voltage Inputs, Input Data Bits

Contents

July SLAA040Application Report TParalInteMS3rflelADConvertertotheacing20C54xDSPtheTLV1562 IMPORTANT NOTICE Contents 8.5.5 List of Figures List of TablesFigures viSLAA040 Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 1 Introduction2 The Board 2.1 TMS320C54x Starter Kit 2.2 TLV1562EVM 2.3 ADC TLV1562 Overview2.3.1 Suggestions for the ’C54x to TLV1562 Interface 2.3.1.1 The Universal Interface Using RD or the CSTART Signal to Start Conversion 2.3.2 Recyclic ArchitectureFigure 2. TLV1562 to ’C54x DSP Interface of the EVM 2.3.3 Note on the Interface, Using an External ADC Clock Drive 2.4 Onboard Components2.4.1 TLC5618A - Serial DAC 2.4.2 THS5651 - Parallel Output CommsDAC Figure 3. TLC5618A to ’C542 DSP InterfaceFigure 4. THS5651 to C542 DSP Interface 3 Operational Overview 3.1 Reference Voltage Inputs3.2 Input Data Bits Table 1. Signal Connections 3.3 Connections Between the DSP and the EVM 3.3.1 Jumpers Used on the TLV1562EVM Table 2. 3-Position JumpersTable 3. 2-Position Jumpers 8SLAA040 4 The Serial DAC/DSP System Table 4. DSP/DAC Interconnection Table 5. DSP Serial Port Signals and Registers 5 The DSP Serial Port 6 Other DSP/TLV1562 Signals 6.1 DSP Internal Serial Port Operation 7.2 Mono Interrupt Driven Mode Using RD 7 Conversation Between the TLV1562 and the DSP7.1 Writing to the ADC Table 6. DSP Algorithm for Writing to the ADC Table 7. DSP Algorithm for Mono Interrupt Driven Mode Using RD tDCSL-sample+1ADCSYSCLKtENDATAOUT = 41 ns 7.3 Mono Interrupt Driven Mode Using CSTART Table 8. DSP Algorithm for Mono Interrupt Driven Mode Using CSTART14 SLAA040 7.4 Dual Interrupt Driven Mode Table 9. DSP Algorithm for Dual Interrupt Driven Mode 7.5 Mono Continuous Mode Table 10. DSP Algorithm for Mono Continuous Mode16 SLAA040 7.6 Dual Continuous Mode Table 11. DSP Algorithm for Dual Continuous Mode 8 Software Overview 8.1 Software Development tools8.2 DSP Memory Map Figure 5. Memory Map 8.3.3 Timer Output 8.3 Programming Strategies for the ’C54x, Explanations8.3.1 Optimizing CPU Resources for Maximum Data Rates 8.3.2 Address and Data Bus for I/O Tasks 8.3.5 Generating the Chip Select Signal and the CSTART Signal 8.3.4 Data Page Pointer8.3.6 Interfacing the Serial DAC 5618A to the DSP 8.3.7 Interrupt Latency 8.3.8 Branch Optimization goto/dgoto, call/dcallGOTO MARK MARK DP = #1 ARP = #5 8.3.9 Enabling Software Modules .if/.elseif/.endif 8.4 Software Code Explanation8.4.1 Software Principals of the Interface 8.4.1.2 Timed Solution 8.4.1.1 Software PollingAdvantage Disadvantage 8.4.1.3 Interrupt Driven Solution 8.4.1.5 Setting the Right SwitchesAdvantages Disadvantages Table 12. Switch Settings TaskTable 13. Instruction in the Program Header Step 8.5 Flow Charts and Comments for All Software Modes 8.5.1 The Mono Interrupt Driven Mode Using RD to Start ConversionTable 14. Instruction in the Program Header Step 8.4.1.6 Common Software for all Modes Program Files Other FilesCode verification common file of all modes constants definition Figure 6. Software Flow of the Mono Interrupt Driven Solution 8.5.2 Mono Interrupt Driven Mode Using CSTART to Start Conversion Calibration procedure of the DACIncludes the complete software algorithm to control the monomode Common file of all modes constants definition Initialize SPI SAVEPoll INTO Pin Until h/0 Transition Occurs Pull Down CSTART 8.5.2.1 Throughput Optimization† This only works for one TLV1562 not multiple because CS is not used 8.5.3 Dual Interrupt Driven Mode Figure 8. Time Optimization monocst1Maximum Performance at 1.2 MSPS with Internal Clock IMPORTANT NOTE The code has been optimized to maximize the data throughput. It was found that CSTART can be pulled low earlier than the data read instruction is performed by the DSP. This saves the 100-ns wait time in STEP 3 because the data read requires at least 100 ns. Therefore, CSTART gets pulled high directly after data read, and the interface becomes faster and gains throughput. This variation will be found in the code. The data acquisition is done in a small number of steps that explains everything inside the code Software Overview 8.5.4 Mono Continuous Mode Figure 10. Flow Chart Mono Continuous Mode 8.5.5 Dual Continuous Mode Figure 11. Flow Chart Dual Continuous Mode Program Files 8.6 Source Code 8.6.1 Common Software for all Modes except C-Callable8.6.1.1 Constants.asm set 000C0h Operate without calibrated inputs no offset 42 SLAA040 8.6.1.2 Interrupt Vectors 4C internal timer interrupt 44 SLAA040 8.6.1.3 linker,cmd 8.6.1.4 Auto.batFile Linker.lnk COMMAND FILE title ”COMMAND FILE FOR TLV1562.ASM” Mainprogram Monomode.asm pointer address when using any of the following variablesjump address to init. new channel counter for one channel sent value to register CR0 of the ADC if SENDOUTSERIAL endif if INT0DRIVENPOLLINGDRV48 SLAA040 endif if AUTOPWDNENABLE endif if DIFFINPUTMODE= bit*AR5,15-0 elseif INT0DRIVEN elseif NOINT0SIG 52 SLAA040 8.6.3 Calibration of the ADC CALIBRAT.ASM 54 SLAA040 if SMECALIBRATION 56 SLAA040 Software Overview 58 SLAA040 Software Overview 60 SLAA040 if INT0DRIVENPOLLINGDRV 62 SLAA040 = bit*AR5,15-0 endif if SAVEINTOMEMORY 64 SLAA040 Software Overview 8.6.5 Dual Interrupt Driven Mode Constants definition - see 8.6.1.1 Constants.asmInterrupt Routine handler - see 8.6.1.2 Interrupt Vectors Mainprogram DUALIRQ1.asm Software Overview Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overview if SENDOUTSERIAL Software Overview 70 SLAA040 if AUTOPWDNENABLE 72 SLAA040 Software Overview 8.6.6 Mono Continuous Mode Mainprogram MONOCON1.asm74 SLAA040 Software Overview 76 SLAA040 endif if EXTERNALCLOCK 78 SLAA040 Software Overview 8.6.7 Dual Continuous Mode Mainprogram DUALCON1.asm80 SLAA040 Software Overview 82 SLAA040 Software Overview 84 SLAA040 Software Overview 8.6.8 C-Callable Mainprogram C1562.cTLV1562Channel, Save Memory Start address, NUMBEROFSAMPLES 80h samples of channel 1 will be stored beginning on 2000h Software Overview 88 SLAA040 AR7+ = data@ADSAMPLE Vectors.asm 90 SLAA040 int2 returnenable 48 external interrupt int2 nop Auto.bat Linker.cmd92 SLAA040 9 Summary 10 References