Texas Instruments TLV1562 manual Software Overview, elseif R4BITRESOLUT, SLAA040

Page 68

62SLAA040

Software Overview

.elseif (R4BIT_RESOLUT)
@CR1_SEND ^= #RES_10_BIT	; clear bit for 10–Bit Resolution
@CR1_SEND = #RES_4_BIT	; set 8–Bit conversion mode
.endif
.if (EXTERNAL_CLOCK)
@CR0_SEND ^= #CLK_INTERNAL	; clear CLK_INTERNAL bit if one
@CR0_SEND = #CLK_EXTERNAL	; set CLK_EXTERNAL mode
.endif
.if (AUTO_PWDN_ENABLE)
@CR1_SEND ^= #NO_AUTO_PWDN	; clear NO_AUTO_PWDN bit if one
@CR1_SEND = #AUTO_PWDN	; set AUTO_PWDN mode
.endif

.if (DIFF_INPUT_MODE)

@CR0_SEND ^= #SINGLE_END ; clear single ended input bit if one @CR0_SEND = #DIFFERENTIAL ; set differential input mode

.endif

.if (IME_CALIBRATION)

call CALIBRAT_INTERNAL_MID_SCALE

.endif

.if (SME_CALIBRATION)

call CALIBRAT_SYSTEM_MID_SCALE

.endif

****************************

*ADC_INI:

*set ADC register CR0/CR1

****************************

ADC_INI:

*write CR1 (to reset old CSTART mode initialization, because otherwise, the ADC never sets

*back its int– pin to show a sample is available:

@CR_PROBLEM = #(SW_PWDNNO_AUTO_PWDNNO_2COMPLEMENTNO_DEBUGRES_10_BITRD_CONV_START);

port(ADC) = @CR_PROBLEM	; Address	decoder sets CS low,
	; WR– low	and send CR_PROBLEM value to the ADC
NOP	; wait for tW(CSH)=50ns
* write CR1:

port(ADC) = @CR1_SEND	; Address decoder sets CS low,
	; WR– low and send CR1 value to the ADC

port(DEACTIVE) = @ZERO	; deselect ADC (CS high)
NOP	; wait for tW(CSH)=50ns

62SLAA040

Image 68

Contents July SLAA040Application Report TParalInteMS3rflelADConvertertotheacing20C54xDSPtheTLV1562IMPORTANT NOTICE Contents 8.5.5 Figures List of FiguresList of Tables viSLAA040 Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 1 Introduction2 The Board 2.1 TMS320C54x Starter Kit2.2 TLV1562EVM 2.3 ADC TLV1562 Overview2.3.1 Suggestions for the ’C54x to TLV1562 Interface 2.3.1.1 The Universal 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 Table 1. Signal Connections 3.3 Connections Between the DSP and the EVM3.3.1 Jumpers Used on the TLV1562EVM Table 2. 3-Position JumpersTable 3. 2-Position Jumpers 8SLAA0404 The Serial DAC/DSP System Table 4. DSP/DAC InterconnectionTable 5. DSP Serial Port Signals and Registers 5 The DSP Serial Port6 Other DSP/TLV1562 Signals 6.1 DSP Internal Serial Port Operation7.2 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 ADCtENDATAOUT = 41 ns Table 7. DSP Algorithm for Mono Interrupt Driven Mode Using RDtDCSL-sample+1ADCSYSCLK 14 SLAA040 7.3 Mono Interrupt Driven Mode Using CSTARTTable 8. DSP Algorithm for Mono Interrupt Driven Mode Using CSTART 7.4 Dual Interrupt Driven Mode Table 9. DSP Algorithm for Dual Interrupt Driven Mode16 SLAA040 7.5 Mono Continuous ModeTable 10. DSP Algorithm for Mono Continuous Mode 7.6 Dual Continuous Mode Table 11. DSP Algorithm for Dual Continuous Mode8.2 DSP Memory Map 8 Software Overview8.1 Software Development tools 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 Tasks8.3.6 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 8.3.7 Interrupt Latency 8.3.8 Branch Optimization goto/dgoto, call/dcallGOTO MARK MARK DP = #1 ARP = #58.4.1 Software Principals of the Interface 8.3.9 Enabling Software Modules .if/.elseif/.endif8.4 Software Code Explanation 8.4.1.2 Timed Solution 8.4.1.1 Software PollingAdvantage Disadvantage8.4.1.3 Interrupt Driven Solution 8.4.1.5 Setting the Right SwitchesAdvantages DisadvantagesTable 13. Instruction in the Program Header Step Table 12. Switch SettingsTask 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 ModesProgram Files Other FilesCode verification common file of all modes constants definitionFigure 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 definitionInitialize SPI SAVEPoll INTO Pin Until h/0 Transition Occurs Pull Down CSTART8.5.2.1 Throughput Optimization† This only works for one TLV1562 not multiple because CS is not usedMaximum Performance at 1.2 MSPS with Internal Clock 8.5.3 Dual Interrupt Driven ModeFigure 8. Time Optimization monocst1 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 Code verification 8.6.1.1 Constants.asm 8.6 Source Code8.6.1 Common Software for all Modes except C-Callable set 000C0h Operate without calibrated inputs no offset 42 SLAA0408.6.1.2 Interrupt Vectors 4C internal timer interrupt 44 SLAA0408.6.1.3 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 channelsent value to register CR0 of the ADC 48 SLAA040 if SENDOUTSERIALendif if INT0DRIVENPOLLINGDRV endif if AUTOPWDNENABLE endif if DIFFINPUTMODE= bit*AR5,15-0 elseif INT0DRIVENelseif NOINT0SIG 52 SLAA040 8.6.3 Calibration of the ADC CALIBRAT.ASM54 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 SLAA040Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 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.asmSoftware Overview Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSPSoftware Overview if SENDOUTSERIALInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 70 SLAA040 if AUTOPWDNENABLE 72 SLAA040 Software Overview 74 SLAA040 8.6.6 Mono Continuous ModeMainprogram MONOCON1.asm Software Overview 76 SLAA040 endif if EXTERNALCLOCK 78 SLAA040 Software Overview 80 SLAA040 8.6.7 Dual Continuous ModeMainprogram DUALCON1.asm 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 2000hSoftware Overview 88 SLAA040 AR7+ = data@ADSAMPLE Vectors.asm 90 SLAA040int2 returnenable 48 external interrupt int2 nop 92 SLAA040 Auto.batLinker.cmd 9 Summary 10 References