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Texas Instruments TLV1562 2.4.2 THS5651 - Parallel Output CommsDAC, THS5651 to C542 DSP Interface

Models: TLV1562

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Figure 3. TLC5618A to ’C542 DSP Interface

The Board

Serial DAC

SCLK

TLC5618A

DIN

DSP

BCLKX

BCLKR

BFSX TMS320C542

BFSR

BDX

BDR

TLV1562 EVM Pin Connector

Figure 3. TLC5618A to ’C542 DSP Interface

2.4.2THS5651 – Parallel Output CommsDAC

This 10-bit data converter has a parallel interface and is able to update its output with 100 MSPS. The two outputs on the 28-pin package can each drive a current between 2 mA and 20 mA with an output resistance >100 kΩ (ideal current source: output impedance → ∞ ). The data bus and the address decoder provide the interface to the DSP.

Parallel DAC	DSP
CLK	CLKOUT
THS5651	TMS320C542
	A(0–1) = 11b
D(0–9)	D(0–9)
	Buffer

Figure 4. THS5651 to C542 DSP Interface

Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP

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Texas Instruments TLV1562 manual 2.4.2 THS5651 - Parallel Output CommsDAC, TLC5618A to ’C542 DSP Interface

Contents

TParalInteMS3rflelADConvertertotheacing20C54xDSPtheTLV1562 JulySLAA040 Application ReportIMPORTANT NOTICE Contents 8.5.5 Interfacing the TLV1562 Parallel AD-Converter to the TMS320C54x DSP List of FiguresList of Tables FiguresviSLAA040 2.1 TMS320C54x Starter Kit Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP1 Introduction 2 The Board2.3.1.1 The Universal Interface 2.2 TLV1562EVM2.3 ADC TLV1562 Overview 2.3.1 Suggestions for the ’C54x to TLV1562 InterfaceFigure 2. TLV1562 to ’C54x DSP Interface of the EVM Using RD or the CSTART Signal to Start Conversion2.3.2 Recyclic Architecture 2.4.1 TLC5618A - Serial DAC 2.3.3 Note on the Interface, Using an External ADC Clock Drive2.4 Onboard Components Figure 4. THS5651 to C542 DSP Interface 2.4.2 THS5651 - Parallel Output CommsDACFigure 3. TLC5618A to ’C542 DSP Interface 3.2 Input Data Bits 3 Operational Overview3.1 Reference Voltage Inputs 3.3 Connections Between the DSP and the EVM Table 1. Signal ConnectionsOperational Overview 3.3.1 Jumpers Used on the TLV1562EVMTable 2. 3-Position Jumpers Table 3. 2-Position JumpersTable 4. DSP/DAC Interconnection 4 The Serial DAC/DSP System5 The DSP Serial Port Table 5. DSP Serial Port Signals and Registers6.1 DSP Internal Serial Port Operation 6 Other DSP/TLV1562 SignalsTable 6. DSP Algorithm for Writing to the ADC 7.2 Mono Interrupt Driven Mode Using RD7 Conversation Between the TLV1562 and the DSP 7.1 Writing to the ADCtDCSL-sample+1ADCSYSCLK Table 7. DSP Algorithm for Mono Interrupt Driven Mode Using RDConversation Between the TLV1562 and the DSP Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP14 SLAA040 7.3 Mono Interrupt Driven Mode Using CSTARTTable 8. DSP Algorithm for Mono Interrupt Driven Mode Using CSTART Conversation Between the TLV1562 and the DSPInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 7.4 Dual Interrupt Driven ModeTable 9. DSP Algorithm for Dual Interrupt Driven Mode Conversation Between the TLV1562 and the DSP16 SLAA040 7.5 Mono Continuous ModeTable 10. DSP Algorithm for Mono Continuous Mode Conversation Between the TLV1562 and the DSPInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 7.6 Dual Continuous ModeTable 11. DSP Algorithm for Dual Continuous Mode Conversation Between the TLV1562 and the DSP8.2 DSP Memory Map 8 Software Overview8.1 Software Development tools Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Figure 5. Memory MapSoftware Overview 8.3.2 Address and Data Bus for I/O Tasks 8.3.3 Timer Output8.3 Programming Strategies for the ’C54x, Explanations 8.3.1 Optimizing CPU Resources for Maximum Data Rates8.3.6 Interfacing the Serial DAC 5618A to the DSP 8.3.5 Generating the Chip Select Signal and the CSTART Signal8.3.4 Data Page Pointer MARK DP = #1 ARP = #5 8.3.7 Interrupt Latency8.3.8 Branch Optimization goto/dgoto, call/dcall GOTO MARK8.4.1 Software Principals of the Interface 8.3.9 Enabling Software Modules .if/.elseif/.endif8.4 Software Code Explanation Disadvantage 8.4.1.2 Timed Solution8.4.1.1 Software Polling AdvantageAdvantages 8.4.1.3 Interrupt Driven Solution8.4.1.4 Enabling One Software Mode 8.4.1.5 Setting the Right SwitchesTable 13. Instruction in the Program Header Step Table 12. Switch SettingsTask 8.4.1.6 Common Software for all Modes 8.5 Flow Charts and Comments for All Software Modes8.5.1 The Mono Interrupt Driven Mode Using RD to Start Conversion Table 14. Instruction in the Program Header Stepcommon file of all modes constants definition Program FilesOther Files Code verificationInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Figure 6. Software Flow of the Mono Interrupt Driven SolutionSoftware Overview Other Files 8.5.2 Mono Interrupt Driven Mode Using CSTART to Start ConversionCalibration procedure of the DAC Program FilesSAVE Software OverviewInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Initialize SPIThis only works for one TLV1562 not multiple because CS is not used 8.5.2.1 Throughput Optimization†Program Files 8.5.3 Dual Interrupt Driven ModeFigure 8. Time Optimization monocst1 Maximum Performance at 1.2 MSPS with Internal ClockCode verification 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 codeInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software OverviewCode verification 8.5.4 Mono Continuous ModeProgram Files Other FilesInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Figure 10. Flow Chart Mono Continuous ModeSoftware Overview Code verification 8.5.5 Dual Continuous ModeProgram Files Other FilesInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Figure 11. Flow Chart Dual Continuous ModeSoftware Overview Code verification Program FilesOther Files Software Overview 8.6 Source Code8.6.1 Common Software for all Modes except C-Callable 8.6.1.1 Constants.asm42 SLAA040 Software Overviewset 000C0h Operate without calibrated inputs no offset Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 8.6.1.2 Interrupt VectorsSoftware Overview 44 SLAA040 4C internal timer interruptSoftware Overview title ”COMMAND FILE FOR TLV1562.ASM” 8.6.1.3 linker,cmd8.6.1.4 Auto.bat File Linker.lnk COMMAND FILEjump address to init. new channel Mainprogram Monomode.asmpointer address when using any of the following variables Software OverviewInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewsent value to register CR0 of the ADC 48 SLAA040 Software Overviewif SENDOUTSERIAL endif if INT0DRIVENPOLLINGDRVInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewendif endif if AUTOPWDNENABLESoftware Overview endif if DIFFINPUTMODEInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewelseif NOINT0SIG 52 SLAA040 endifInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 8.6.3 Calibration of the ADCCALIBRAT.ASM Software Overview54 SLAA040 Software OverviewInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewendif if SMECALIBRATION56 SLAA040 Software OverviewInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewendif endif58 SLAA040 Mainprogram Monomode.asmSoftware Overview Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overview60 SLAA040 Software Overviewif SENDOUTSERIAL endif Software Overviewendif if INT0DRIVENPOLLINGDRV62 SLAA040 Software Overviewelseif R4BITRESOLUT elseif INT0DRIVEN Software Overviewif POLLINGDRV = bit*AR5,15-0if SENDOUTPARALLEL Software Overviewif INT0DRIVEN endifInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewendif Mainprogram DUALIRQ1.asm 8.6.5 Dual Interrupt Driven ModeConstants definition - see 8.6.1.1 Constants.asm Interrupt Routine handler - see 8.6.1.2 Interrupt VectorsInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewif SENDOUTSERIAL Software OverviewInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewendif endif if AUTOPWDNENABLESoftware Overview if EXTERNALCLOCKif POLLINGDRV if AUTOPWDNENABLESoftware Overview endifif INT0DRIVEN if AUTOPWDNENABLESoftware Overview endifendif Software Overviewendif if SAVEINTOMEMORYInterrupt Routine handler - see 8.6.1.2 Interrupt Vectors 8.6.6 Mono Continuous ModeMainprogram MONOCON1.asm Constants definition - see 8.6.1.1 Constants.asmInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewif R8BITRESOLUT Software Overviewif SENDOUTSERIAL endifendif Software Overviewendif if EXTERNALCLOCK endif if DIFFINPUTMODEendif if SENDOUTSERIAL Software Overviewif SENDOUTPARALLEL endif if SAVEINTOMEMORYInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewendif if SAVEINTOMEMORY endifInterrupt Routine handler - see 8.6.1.2 Interrupt Vectors 8.6.7 Dual Continuous ModeMainprogram DUALCON1.asm Constants definition - see 8.6.1.1 Constants.asmInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewif R8BITRESOLUT Software Overviewif SENDOUTSERIAL endifendif Software Overviewendif if EXTERNALCLOCK endif if DIFFINPUTMODEendif if SENDOUTSERIAL Software Overviewif SENDOUTPARALLEL endif if SAVEINTOMEMORYInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software OverviewInterrupt Routine handler - see 8.6.1.2 Interrupt Vectors 8.6.8 C-CallableMainprogram C1562.c Constants definition - see 8.6.1.1 Constants.asmInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overview88 SLAA040 Software OverviewInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overview= bit*AR5,15-0 AR7+ = data@ADSAMPLE90 SLAA040 Vectors.asmSoftware Overview Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP int2 returnenable 48 external interrupt int2 nopSoftware Overview title ”COMMAND FILE FOR TLV1562.ASM” Auto.batLinker.cmd File Linker.lnk COMMAND FILE10 References 9 Summary