analog interfacing chapter 6.5 (optional) c6000 integration workshop copyright © 2005 texas...

Analog Interfacing

Chapter 6.5 (Optional)

C6000 Integration Workshop

Copyright © 2005 Texas Instruments. All rights reserved. Technical Training

Organization

T TO

Learning Objectives

List various families of TI Analog that connect to DSP systems

Demonstrate how to find information on TI Analog components

List key and additional selection criteria for an A2D converter

Identify challenges in adding peripherals to a DSP design

Identify TI support to meet above design challenges

Describe the types of Analog EVMs available from TI

Select and configure a desired analog system from available EVMs

Create driver code with the Data Converter Plug-In

Apply Plug-in generated code to a given system

Technical TrainingOrganization

T TO2

Interfacing TI DSP to TI Analog

TI Analog

Finding Information

Data Converters

Selecting An Example ADC

Development Challenges

Analog EVMs

Data Converter Plug-In

Completing the Code

Build, Run, Evaluate

Lessons Learned

Additional Information…

A/D11100010011


T TO3

TI Analog

ADC

Da

ta T

r an

s

POWERSOLUTION

DAC

OP-AMPs/Comparators/Support- High Speed Amplifiers- Low Power, RRIO Signal Amps- Instrumentation Amps- Audio Power Amps- Power Amps- Commodity Amps- Comparators- Temp Sensors- References- Special Functions

Data Converter-Standard A/D and D/A- High Resolution/Precision converters- High Speed converters- Touchscreen controllers- -Law/A-Law Telecom “SLAC”s- Communication, Video, & Ultrasound optimized converters/codecs- Audio & Voice band converters/Codecs- Industrial converters

Data Transmission- Many standards- SERDES

STANDARDSRS232RS422RS485LVDS1394/FirewireUSBPCICANSONETGigabit EthernetGTL, BTL, etc.

Power- Power Modules- Linear Regulators/ LDOs- DC-DC controllers- PFC- Load Share- Battery Management- Charge Pumps & Boost Converters- Supervisory Circuits- Power Distribution/Hotswap- References

(Codec)

RF

RF (or Wireless)

DATATRANSMISSION

DigitalMSP430TI DSP

etc

ClockingSolution

Anothersystem/

subsystem/etc.

Da ta T

rans

Clocks• Clock Buffer & fanouts• PLL based buffers & fanouts• Multipliers & Dividers• Jitter cleaners & synchronizers• Memory specific solutions• Synthesizers• Real Time Clocks

4

TI’s High-Performance Analog Portfolio


T TO5

$ 3.45 B

$ 3.41 B

$ 1.62 B

$ 1.49 B

$ 1.39 B

11.0 %

10.8 %

5.1 %

4.7 %

4.4 %

Industry Ranking

Data Converters Amplifiers Power Management Interface

ADI ADI TI TI

TI TI NSC Maxim

Maxim NSC LTC NSC

NSC LTC FSC Toshiba

ISL Maxim ON ADI

Data Converters Amplifiers Power Management Interface

ADI ADI TI TI

TI TI NSC Maxim

Maxim NSC LTC NSC

NSC LTC FSC Toshiba

ISL Maxim ON ADI

1. TI

2. STM

3. Infineon

4. ADI

5. Philips


T TO6


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO7

http://analog.ti.com

Booklet :

SSDV004N

DSP Selection Guide

Booklet :

SSDV004N

DSP Selection Guide8

On-Line Data Converter App Notes

Most contain downloadable software examples for use with CCS or Embedded Workbench!

Most contain downloadable software examples for use with CCS or Embedded Workbench!

Click on “Application Notes” from the Product Folder for links to specific devices

Click on “Application Notes” from the Product Folder for links to specific devices

9

Amplifier Design Utilities

10

FilterPro Design Tool

11

SWIFT Design Tool

12

The I-to-V Pro Tool

13


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO14

Application Areas for TI Data Converters

Embedded High Perf. DSP Portable / Low Power Micro Systems

High PrecisionMeasurement

Over Sampling ∆Σ ADCs Precision ADCs Micro Systems High Speed ADCs Current Input ADC’s

Touch-Screen Controller

Stand-Alone Intelligent Integrated Audio

Audio Voiceband Codecs Consumer Professional Audio

High Speed Comm /Ultrasound

Pipeline ADCs Current Steering DACs

Industrial Control /Instrumentation

SAR ADCs High Speed Low Power Simultaneous Sampling Bipolar Data Acquisition Systems

String / R2R DACs Single Supply Monitor & Control Dual Supply


T TO15

1K10010 10K 100K 1M 10M 100M

24

20

16

12

8

Pipeline

SAR Successive

Approximation

Oversampling

ADS1625 18 bit Delta Sigma 1.25 MSPS - Fastest on the market (averages and filters out noise)

ADS1605 16 bit Delta Sigma 5 MSPS ADS8411

16 bit 2 MSPS Market Leader ADS5500

14 bit 125 MSPS Market Leader

TI ADC Technologies

Current Technology

Con

vert

er R

esol

utio

n

Conversion RateTechnical Training

Organization

T TO16

TI DAC Technologies

Settling Time- s

20

16

12

8

Current

Steering

Resistor String

& R-2R

Con

vert

er R

esol

utio

n

6810 4 2 1 .05 .0011001000

Current Technology

High Speed Video and CommunicationUpdate rate (MSPS)Typically 1 Output but a few 2 OutputCurrent out

IndustrialSettling Time (µs)Number of Out put DACsResistor String – InexpensiveR-2R – More accurate -Trimmed at final test Typically Voltage outMDAC’s coming (dig control gain/atten, Waveform gen.)

Instrumentation & MeasurementTypically for Calibration

Current Technology


T TO17

DACs – Delta SigmaDACs – Delta Sigma

High Resolution/AccuracyDAC122X

Touch Screen ControllersTouch Screen Controllers

Stand Alone Controllers Integrated Audio Controllers

TI Data Converters

High Precision Low bandwidthHigh Bandwidth

Intelligent / high resolution8051 core

ADCs – Delta SigmaADCs – Delta Sigma

High PrecisionMedical, Industrial Control,

Data Acquisition Simultaneous sampling

Motor control

ADCs – SARADCs – SAR

Versatile, High Speed Communication, Imaging,

Ultrasound

ADCs – PipelineADCs – Pipeline

Low power, Single and bipolar Suppy, Precision

DACs – String / R2RDACs – String / R2R

Consumer Codecs, ADC/DACVoice A/C Codecs

Pro audio DACs, ADCs PGAs, SRCs, DITs

AudioAudio


T TO18


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO19

Go to “ti.com” with your browser

In the Products box, hover over Analog and Mixed Signal & select Data Converters

In the Data Converters Home box in the upper left, hover over Find a Device and select Parametric Search

Pick a bit resolution and sample rate, and a list of suitable devices are displayed, comparing numerous additional parameters, including:

Device name Status Resolution Sample Rate

Architecture # Channels SE vs Diff’l Pwr Consumpt’n

SINAD SNR SFDR ENOB

Voltage ranges Bandwidth # supplies Pins/Pkg

Selecting a Device


T TO20

ADS8361from : http://focus.ti.com/docs/prod/folders/print/ads8361.html

Resolution (Bits) 16 Sample Rate (max) 500 KSPS Search Sample Rate (Max) (SPS) 500000

# Input Channels (Diff) 4 Power Consumption (Typ) (mW) 150

SNR (dB) 83 SFDR (dB) 94 DNL (Max) (+/-LSB) 1.5 INL (Max) (+/-LSB) 4 INL (+/- %) (Max) 0.00375 No Missing Codes (Bits) 14 Analog Voltage AV/DD (Min/Max) (V) 4.75 / 5.25

Logic Voltage DV/DD (Min / Max) (V) 2.7 / 5.5 Input Type Voltage Input Configuration Range +/-2.5 V at 2.5 No. of Supplies 2


T TO21


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO22

Design Flow… Product Selection

Key specifications (speed, resolution, …) Secondary parameters (power, size, price, channels, …) Research data base of candidate devices Additional factors: ease of use, cost/value

Hardware Design ADC / DAC pins, requirements DSP pin matchup Layout considerations (noise, supply requirements, etc

Software Authoring Configuring the (serial) port Configuring the peripheral Getting/sending data from/to the peripheral How? Write it yourself or with the help of an authoring tool…


T TO23

I/O Device Development Challenges

Hardware Design

Pinouts, etc

Layout – noise minimization, etc

Software Design

Select modes for serial port

Select modes for ADC / DAC

Write modes to port / peripheral

Debug

Observe / verify performance

Modify design as required

Analog Evaluation Modules

(EVMs) : ADC, DAC, Power, ...

Chip Support Library (CSL) + Data Converter Plug-In (DCP)

CCS


T TO24


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO25

Signal Chain Prototyping System

Dig

ital

An

alo

g

Power

Interface BoardPower Supply EVMA/D EVM (THS1206)DAC EVM (ADS8345)


T TO26

Analog EVMs 5-6K Interface Board

Compatible with TMS320 C5000 and C6000 series DSP starter kits Supports parallel EVM’s up to 24 bits Allows multiple clock sources for parallel/Serial converters Supports two independent McBSP channels Provides complete signal chain prototyping opportunities

Data Converter EVMs 3 standardized daughter card format (2 serial, 1 parallel)

Serial – support for SPI, McBSP, I2C; 1-16 I/O channels Connects to (nearly) any control system Stackable

Third Party Interface Boards Avnet, SoftBaugh, Spectrum Digital, Insight - Memec Design …

Analog Interface Boards Bipolar and single supply In development – differential amps, instrumentation amps, active filters

$50 each!


T TO27


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO28


Allows rapid application development

Automatically generates required DSP source code

Removes the necessity to learn the converter “bit by bit”

Includes help for device features

Fully integrated into Code Composer Studio (2, 5, and 6K)

29

Launching the Data Converter Plug-In

30

Adding an Instance of the Desired Converter

31

Specify the ConfigurationDefine the DSP properties

Set desired ADC modes

Write files…

32

DCP Files Added to CCS Project

“API” file prototypes the 6 functions generated by the DCPin tool

Object file implements all device coding and creates structures that manage the behavior of the device

33

Files Generated by Data Converter Plug-In

tidc_api.c

Set of API that all Data Converter Plug-In authored code supports

tidc_api.h

Header file common to all Data Converter Plug-In generated code

dc_conf.h

Configuration data that holds the selections made in the Plug-In

tads8361_ob.c

Implementation of the API for the given device instance

tads8361.h

Header file to define the exposed object specific elements

All are fully coded by the Plug-In

All are fully exposed to the user for study/modification as desired


T TO34

Data Converter Plug-In Uniform API

DCPAPI TTIDCSTATUS dc_configure(void *pDC);

DCPAPI long dc_read(void *pDC);

DCPAPI void dc_rblock(void *pDC, void *pData, unsigned long ulCount, void (*callback) (void *));

DCPAPI void dc_write(void *pDC, long lData);

DCPAPI void dc_wblock(void *pDC, void *pData, unsigned long ulCount, void (*callback) (void *));

DCPAPI void dc_power(void *pDC, int bDown);

All objects created with the Data Converter Plug-In share these six API


T TO35

Data Converter Plug-In StructuresTADS8361

*configure // DC API *power *read *write *rblock *wblock 0, 0, 0, 0, // unused *CallBack serial iMode Buffer // data bk ptr ulBuffSize // data bk size iXferInProgress

DCP_SERIAL

port intnum hMcBsp sConfig

MCBSP_Obj

allocated

xmtEventId

rcvEventId

*baseAddr

drrAddr

dxrAddr

hADC

CSL Config

Structure

Interacting with the structures...

TADS8361 * hADC; // make a handle to the DC structurehADC = &Ads8361_1; // initialize handle to point to our instanceMCBSP_getRcvAddr(hADC->serial->hMcbsp); // obtain info from instance object->substruc


T TO36

Data Converter Plug-In Review

Greatly reduces development time For the DSP software developer: No need to learn

the details of the converter For the analog designer: No need to learn DSP

programming to test a give data converter Supports 117 devices on 5 DSP platforms Where to get the Data Converter Plug-In plug-in :

Included in Code Composer Studio Download (free of charge) from :

http://www.ti.com/sc/dcplug-in


T TO37


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO38

Adapting Lab 6 Codemain.c#include "dc_conf.h"#include "t8361_fn.h“...initMcBSP();

dc_configure(&Ads8361_1)

mcbsp.c

...

MCBSP_close(hMcbspControl);

*((unsigned char*)0x90080006) |= 0x01;

edma.c

hEdmaRcv = EDMA_open(EDMA_CHA_REVT1, EDMA_OPEN_RESET);

gEdmaConfigRcv.src = MCBSP_getRcvAddr(hMcbspData);gEdmaConfigRcv.src = MCBSP_getRcvAddr(hADC->serial->hMcbsp);

hEdmaRcv = EDMA_open(EDMA_CHA_REVT0, EDMA_OPEN_RESET);

if (dc_configure(&Ads8361_1) != TIDC_NO_ERR)return;

TADS8361 * hADC;

hADC = &Ads8361_1;

39


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO40

Observations of ResultsAudio sounded ‘scratchy’ - Why?

8361 puts channel number in 2 MSBs

We can adapt the CSL structure to change this

We could mask off those bits before passing data to the algo

In “real life”, we’d probably want these bits to verify channel #

Mismatched data rates between input and output

In real-life situation, one wouldn’t still be using half a codec, so this problem would not have been encountered normally

If such a case did arise, we could have:

Rewired the ADC to run off the clocks provided by the codec

Adjusted rates to match in software

Sample-rate converted in the DSPTechnical Training

Organization

T TO41


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO42

Conclusions on TI DSP + TI Analog …

TI offers a large number of low cost analog EVMs to allow developers to ‘snap together’ a signal chain for ultra-fast test and debug of proposed components

TI provides CSL and Data Converter Plug-In to vastly reduce the effort in getting a DSP to talk to ports and peripherals

Getting to ‘signs of life’ result is now a matter of minutes instead of days/weeks

Final tuning will sometimes be required, but amounts to a manageable effort with a device already easily observed, rather than ‘groping in the dark’ as often was the case otherwise


T TO43


A/D11100010011

TI Analog

Finding Information

Data Converters



Analog EVMs


Completing the Code


Lessons Learned



T TO44

Driver Object Details

long ads8361_read(void *pDC) prototype of the DC API { TADS8361 *pADS = pDC; get handle to object

if (!pADS) return; parameter check if (pADS->iXferInProgress) return; verify no bk op in progresswhile (!MCBSP_rrdy(pADS->serial->hMcbsp)); actual SP ops use CSL APIreturn MCBSP_read(pADS->serial->hMcbsp); when SP ready, return data rcvd

} spin loop – oops ! !

t8361_ob.c code to implement the DC API, eg: read fn

TADS8361 Ads8361_1 = {&ads8361_configure,&ads8361_power,&ads8361_read,&ads8361_write,&ads8361_rblock,&ads8361_wblock,0, 0, 0, 0, 0, &serial0, ADC1_MODE,0, 0, 0

};

t8361_ob.c make & fill instance obj

typedef struct {TTIDC f; // std DC APIvoid (*CallBack)(void *);DCP_SERIAL *serial;int iMode;int* Buffer;unsigned long ulBuffSize;volatile int iXferInProgress;

} TADS8361;

t8361_ob.c define instance object type


T TO45

Structure Definitionstypedef struct { unsigned int port; Number of serial port used unsigned short intnum; Which interrupt driver uses MCBSP_HANDLE hMcbsp; Serial port handle (CSL) MCBSP_CONFIG sConfig; Ptr to CSL ser pt config struc} DCP_SERIAL;

typedef struct { Uint32 allocated; Is port available? Uint32 xmtEventId; Which ints port will use Uint32 rcvEventId; volatile Uint32 *baseAddr; Address of port registers Uint32 drrAddr; *Data receive register Uint32 dxrAddr; *Data transmit register} MCBSP_Obj, *MCBSP_Handle;

from TIDC_API.h

from csl_mcbsp.h

typedef struct { TTIDCSTATUS (*configure) (void *pDc);void (*power) (void *pDc, int bDown);long (*read) (void *pDc);void (*write) (void *pDc, long lData); void (*rblock) (void *pDC, void *pData, unsigned long ulCount, void (*callback) (void *));void (*wblock) (void *pDC, void *pData, unsigned long ulCount, void (*callback) (void *));void* reserved[4];

} TTIDC;

typedef struct { TTIDCSTATUS (*configure) (void *pDc);void (*power) (void *pDc, int bDown);long (*read) (void *pDc);void (*write) (void *pDc, long lData); void (*rblock) (void *pDC, void *pData, unsigned long ulCount, void (*callback) (void *));void (*wblock) (void *pDC, void *pData, unsigned long ulCount, void (*callback) (void *));void* reserved[4];

} TTIDC;

from TIDC_API.h


T TO46

Analog Design Tools in Development

OpAmpPro - Input data selects IC Input data contains transfer function Input data selects the appropriate circuit Program enables adjustment resistor & worst case calculations Op Amp Pro selects IC by analyzing applications and input data Calculates error due to external component & IC tolerances

Tina-TI Spice Simulation Program To be offered free on www.ti.com Uses TI’s SPICE macromodels Allows general spice circuit simulation Analysis Circuit optimization


T TO47

Example Analysis Circuit

Vcommon-mode

Vsample

Vinput

+ Vsample

+ Vinput

C4

10

0p

C3 100p

Vout

Vreference 5

R5 40k

+Vcommon-mode

C2 25p

C1

1n

R6 100

R4

40

k

V1 5

R3 100k

R2 100k R1 20k

-

+ +U1 OPA364

ADS8325 16-bit1/2 lsb = 38uVtaq < 1.875uSCin = 20pf

ADS7829 12-bit1/2 lsb = 610uVtaq < 750nSCin = 25pF

ADS Reference

+/- 10V Signal Conditioning for 5V ADC's

"Flywheel"

Conditioning Network analog input


T TO48

ti


49

Lab Setup - DSK

DSK

pwr

usb


T TO50

Lab Setup - I/F Bd

DSK

pwr

usb

5-6K Interface Board

Parallel Bus

I/FSerial “A”

Serial “B”

Analog I/O 1

Analog I/O 2

Serial I/FA

nalog I/F

pwr


T TO51

Lab Setup - EVMs

DSK

pwr

usb

5-6K Interface Board

Parallel Bus

I/FSerial “A”

Serial “B”

Analog I/O 1

Analog I/O 2

ADC8361 EVMAmplifier EVM

Serial I/FA

nalog I/F

pwr


T TO52

Signal Chain Prototyping System

53

analog interfacing chapter 6.5 (optional) c6000 integration workshop copyright © 2005 texas...

Documents

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