Texas Instruments TLV1562 manual Software Overview

Page 81
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Software Overview

isr_save

.usect ”.variabl”,

1

; memory location to save AR7 during

 

 

 

 

; interrupts

ADSAMPLE

.usect ”.variabl”, 1

; last read sample from the ADC

* Address Decoder constants:

 

 

 

 

ADC

.set

00002h

; activate A0 when TLV1562 is choosen

 

 

 

 

 

 

RD_CALIBRATION

.set

00001h

; activate A1 when CSTART is choosen

DAC1

.set

00003h

; activate A2 when DAC1 is choosen

DEACTIVE

.set

00000h

; deactivate the address lines A0, A1 and A2

SAVE_INTO_MEMORY .set

00000h

; store the samples into DSP memory

SEND_OUT_SERIAL .set 00000h

; store the last sample allways into serial buffer memory

SEND_OUT_PARALLEL.set 00001h

; store the last sample allways into DAC1

R10BIT_RESOLUT

.set

00001h

; use maximum resolution of 10-bit

R8BIT_RESOLUT

.set

00000h

; use 8-Bit resolution

R4BIT_RESOLUT

.set

00000h

; use fastest mode (4-Bit resolution)

INTERNAL_CLOCK

.set

00001h

; use the internal clock of the ADC

EXTERNAL_CLOCK

.set

00000h

; use the external clock of the ADC

DIFF_INPUT_MODE .set 00000h

; use differential mode instead of single ended inputs

IME_CALIBRATION .set 00000h

; do an Internal Midscale Error Calibration

SME_CALIBRATION .set 00000h

; do a System Midscale Error Calibration

.sect ”.text”

 

 

 

 

 

 

_MAIN:

START:

INITIALIZATION:

* disable IRQ, sign extension mode, ini Stack

 

INTM

= 1

; disable IRQ

 

SXM

= 0

; no sign extension mode

;

SP

= #0280h

; initialize Stack pointer

* initialize waitstates:

 

 

DP

= #00000h

; point to page zero

 

@SWWSR = #01000h

; one I/O wait states

*copy interrupt routine, which are not critical for the EVM to the IRQ table location:

*this is required for the DSKplus kit but has to be changed on other platforms

DP

= #1

; point to page 1 (IRQ vector table)

AR7

= #00200h

 

 

 

 

 

repeat(#3h)

 

 

 

 

 

data(0084h) = *AR7+

; copy the NMI vector

AR7

= #00240h

 

 

 

 

 

repeat(#35)

 

 

 

 

 

data(00C0h) = *AR7+

 

 

 

 

 

; copy INT0, INT1,...

* clear all memory locations of the sampling table (table, where the samples will be stored)

DP

= #AD_DP

;

@TEMP

= #00000h

;

repeat(#num_data_A–1)

 

Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP

75

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Contents SLAA040 JulyApplication Report TParalInteMS3rflelADConvertertotheacing20C54xDSPtheTLV1562IMPORTANT NOTICE Contents 8.5.5 List of Figures List of TablesFigures viSLAA040 1 Introduction Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP2 The Board 2.1 TMS320C54x Starter Kit2.3 ADC TLV1562 Overview 2.2 TLV1562EVM2.3.1 Suggestions for the ’C54x to TLV1562 Interface 2.3.1.1 The Universal InterfaceUsing 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 3.3 Connections Between the DSP and the EVM Table 1. Signal ConnectionsTable 2. 3-Position Jumpers 3.3.1 Jumpers Used on the TLV1562EVMTable 3. 2-Position Jumpers 8SLAA040Table 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 Signals7 Conversation Between the TLV1562 and the DSP 7.2 Mono Interrupt Driven Mode Using RD7.1 Writing to the ADC Table 6. DSP Algorithm for Writing to the ADCTable 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 Table 9. DSP Algorithm for Dual Interrupt Driven Mode 7.4 Dual Interrupt Driven Mode7.5 Mono Continuous Mode Table 10. DSP Algorithm for Mono Continuous Mode16 SLAA040 Table 11. DSP Algorithm for Dual Continuous Mode 7.6 Dual Continuous Mode8 Software Overview 8.1 Software Development tools8.2 DSP Memory Map Figure 5. Memory Map 8.3 Programming Strategies for the ’C54x, Explanations 8.3.3 Timer Output8.3.1 Optimizing CPU Resources for Maximum Data Rates 8.3.2 Address and Data Bus for I/O Tasks8.3.5 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 8.3.8 Branch Optimization goto/dgoto, call/dcall 8.3.7 Interrupt LatencyGOTO MARK MARK DP = #1 ARP = #58.3.9 Enabling Software Modules .if/.elseif/.endif 8.4 Software Code Explanation8.4.1 Software Principals of the Interface 8.4.1.1 Software Polling 8.4.1.2 Timed SolutionAdvantage Disadvantage8.4.1.5 Setting the Right Switches 8.4.1.3 Interrupt Driven SolutionAdvantages DisadvantagesTable 12. Switch Settings TaskTable 13. Instruction in the Program Header Step 8.5.1 The Mono Interrupt Driven Mode Using RD to Start Conversion 8.5 Flow Charts and Comments for All Software ModesTable 14. Instruction in the Program Header Step 8.4.1.6 Common Software for all ModesOther Files Program FilesCode verification common file of all modes constants definitionFigure 6. Software Flow of the Mono Interrupt Driven Solution Calibration procedure of the DAC 8.5.2 Mono Interrupt Driven Mode Using CSTART to Start ConversionIncludes the complete software algorithm to control the monomode Common file of all modes constants definitionSAVE Initialize SPIPoll INTO Pin Until h/0 Transition Occurs Pull Down CSTARTThis only works for one TLV1562 not multiple because CS is not used 8.5.2.1 Throughput Optimization†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 Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 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 42 SLAA040 set 000C0h Operate without calibrated inputs no offset8.6.1.2 Interrupt Vectors 44 SLAA040 4C internal timer interrupt8.6.1.4 Auto.bat 8.6.1.3 linker,cmdFile Linker.lnk COMMAND FILE title ”COMMAND FILE FOR TLV1562.ASM”pointer address when using any of the following variables Mainprogram Monomode.asmjump address to init. new channel counter for one channelsent value to register CR0 of the ADC if SENDOUTSERIAL endif if INT0DRIVENPOLLINGDRV48 SLAA040 endif endif if DIFFINPUTMODE if AUTOPWDNENABLE= bit*AR5,15-0 elseif INT0DRIVENelseif NOINT0SIG 52 SLAA040 CALIBRAT.ASM 8.6.3 Calibration of the ADC54 SLAA040 if SMECALIBRATION 56 SLAA040 endif 58 SLAA040 Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 60 SLAA040 if INT0DRIVENPOLLINGDRV 62 SLAA040 = bit*AR5,15-0 64 SLAA040 endif if SAVEINTOMEMORYSoftware Overview Constants definition - see 8.6.1.1 Constants.asm 8.6.5 Dual Interrupt Driven ModeInterrupt Routine handler - see 8.6.1.2 Interrupt Vectors Mainprogram DUALIRQ1.asmInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Software Overviewif SENDOUTSERIAL Software OverviewSoftware Overview 70 SLAA040 Software Overview 72 SLAA040 endif 8.6.6 Mono Continuous Mode Mainprogram MONOCON1.asm74 SLAA040 Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 76 SLAA040 endif if EXTERNALCLOCK 78 SLAA040 endif if SAVEINTOMEMORY 8.6.7 Dual Continuous Mode Mainprogram DUALCON1.asm80 SLAA040 Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 82 SLAA040 endif if EXTERNALCLOCK 84 SLAA040 Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP Mainprogram C1562.c 8.6.8 C-CallableTLV1562Channel, Save Memory Start address, NUMBEROFSAMPLES 80h samples of channel 1 will be stored beginning on 2000hInterfacing the TLV1562 Parallel ADC to the TMS320C54x DSP 88 SLAA040 AR7+ = data@ADSAMPLE 90 SLAA040 Vectors.asmint2 returnenable 48 external interrupt int2 nop Auto.bat Linker.cmd92 SLAA040 10 References 9 Summary
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