ANALOG DEVICES ADIS16488 Service Manual

Ten Degrees of Freedom Inertial Sensor

ADIS16488

Rev. B

Trademarks and registered trademarks are the prop erty of their respective owner s.

CONTROLLLER

CLOCK

TRIAXIAL

GYRO

TRIAXIAL

ACCEL

POWER

MANAGEMENT

SCLK

DIN

DOUT

GND

VDD

TEMP

VDD

DIO1 DIO2 DIO3 DIO4

VDDRTC

RST

SPI

TRIAXIAL

MAGN

PRESSURE

SELF-TEST I/O ALARMS

OUTPUT

DATA

REGISTERS

USER

CONTROL

REGISTERS

CALIBRATION

AND

FILTERS

ADIS16488

10277-001

Data Sheet

FEATURES

Triaxial, digital gyroscope, ±450°/sec dynamic range

<±0.05° orthogonal alignment 6°/hr in-run bias stability

0.3°/√hr angular random walk

0.01% nonlinearity Triaxial, digital accelerometer, ±18 g Triaxial, delta angle and delta velocity outputs Triaxial, digital magnetometer, ±2.5 gauss Digital pressure sensor, 300 mbar to 1100 mbar Fast start-up time, ~500 ms Factory-calibrated sensitivity, bias, and axial alignment

Calibration temperature range: −40°C to +70°C SPI-compatible serial interface Embedded temperature sensor Programmable operation and control

Automatic and manual bias correction controls

4 FIR filter banks, 120 configurable taps

Digital I/O: data-ready alarm indicator, external clock

Alarms for condition monitoring

Power-down/sleep mode for power management

Optional external sample clock input: up to 2.4 kHz

Single-command self-test Single-supply operation: 3.0 V to 3.6 V 2000 g shock survivability Operating temperature range: −40°C to +85°C

Tactical Grade

GENERAL DESCRIPTION

The ADIS16488 iSensor® device is a complete inertial system that includes a triaxis gyroscope, a triaxis accelerometer, triaxis magnetometer, and pressure sensor. Each inertial sensor in the

ADIS16488 combines industry-leading iMEMS® technology

with signal conditioning that optimizes dynamic performance. The factory calibration characterizes each sensor for sensitivity, bias, alignment, and linear acceleration (gyroscope bias). As a result, each sensor has its own dynamic compensation formulas that provide accurate sensor measurements.

The ADIS16488 provides a simple, cost-effective method for integrating accurate, multiaxis inertial sensing into industrial systems, especially when compared with the complexity and investment associated with discrete designs. All necessary motion testing and calibration are part of the production process at the factory, greatly reducing system integration time. Tight orthogonal alignment simplifies inertial frame alignment in navigation systems. The SPI and register structure provide a simple interface for data collection and configuration control.

The ADIS16488 uses the same footprint and connector system as the ADIS16375, which greatly simplifies the upgrade process. It comes in a module that is approximately 47 mm × 44 mm × 14 mm and has a standard connector interface.

APPLICATIONS

Platform stabilization and control Navigation Personnel tracking Instrument Robotics

FUNCTIONAL BLOCK DIAGRAM

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Figure 1.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com

ADIS16488 Data Sheet

Features .............................................................................................. 1

Applications ....................................................................................... 1

General Description ......................................................................... 1

Functional Block Diagram .............................................................. 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

Timing Specifications .................................................................. 5

Absolute Maximum Ratings ............................................................ 6

ESD Caution .................................................................................. 6

Pin Configuration and Function Descriptions ............................. 7

Typical Performance Characteristics ............................................. 8

Basic Operation ................................................................................. 9

SPI Communication ................................................................... 10

Device Configuration ................................................................ 10

Reading Sensor Data .................................................................. 10

User Registers .................................................................................. 11

Output Data Registers .................................................................... 14

Inertial Sensor Data Format ...................................................... 14

Rotation Rate (Gyroscope) ........................................................ 14

Acceleration ................................................................................. 15

Delta Angles ................................................................................ 15

Delta Velocity .............................................................................. 16

Magnetometers ........................................................................... 17

Barometer .................................................................................... 17

Internal Temperature ................................................................. 17

Status/Alarm Indicators ............................................................. 18

Firmware Revision ..................................................................... 19

Product Identification ................................................................ 19

Digital Signal Processing ............................................................... 20

Gyroscopes/Accelerometers ..................................................... 20

Averaging/Decimation Filter .................................................... 20

Magnetometer/Barometer ......................................................... 20

FIR Filter Banks .......................................................................... 21

Calibration ....................................................................................... 23

Gyroscopes .................................................................................. 23

Accelerometers ........................................................................... 24

Magnetometers ........................................................................... 24

Barometers .................................................................................. 26

Restoring Factory Calibration .................................................. 26

Point of Percussion Alignment ................................................. 26

Alarms .............................................................................................. 27

Static Alarm Use ......................................................................... 27

Dynamic Alarm Use .................................................................. 27

System Controls .............................................................................. 29

Global Commands ..................................................................... 29

Memory Management ............................................................... 29

General-Purpose I/O ................................................................. 29

Power Management ................................................................... 30

Applications Information .............................................................. 32

Prototype Interface Board ......................................................... 32

Installation Tips .......................................................................... 32

Outline Dimensions ....................................................................... 33

Ordering Guide .......................................................................... 33

REVISION HISTORY

2/12—Rev. A to Rev. B

Change to Features Section ............................................................. 1

Changes to Table 3 ............................................................................ 6

Changes to Figure 7 and Figure 8 ................................................... 8

Changes to Delta Angles Section .................................................. 15

Changes to Delta Velocity Section, Table 31, Table 32, Table 33,

and Table 34 ..................................................................................... 16

Change to Status/Alarm Indicators Section ................................ 18

Changes to Gyroscopes/Accelerometers Section, Averaging/Decimation Filter Section, Magnetometer/Barometer

Section, and Figure 20 .................................................................... 20

Changes to Input Sync/Clock Control Section ........................... 30

Rev. B | Page 2 of 36

Changes to Prototype Interface Board Section and

Figure 26 .......................................................................................... 30

12/11—Rev. 0 to Rev. A

Changes to Specifications Section ................................................... 3

Changes to System/Alarm Indicators Section ............................ 18

Changes to Averaging/Decimation Filter Section ...................... 20

Changes to General-Purpose I/O Section ................................... 29

Changes to Input Sync/Clock Control Section...........................

10/11—Revision 0: Initial Version

Data Sheet ADIS16488

Axis-to-frame (package)

±1.0 Degrees

Linear Acceleration Effect on Bias

Any axis, 1 σ (CONFIG[7] = 1)

0.009

°/sec/g

Initial Sensitivity Tolerance

±0.5

Initial Bias Error

1 σ ±16 mg

MAGNETOMETER

SPECIFICATIONS

TA = 25°C, VDD = 3.3 V, angular rate = 0°/sec, dynamic range = ±450°/sec ± 1 g, 300 mbar to 1100 mbar, unless otherwise noted.

Table 1.

Parameter Test Conditions/Comments Min Typ Max Unit

GYROSCOPES

Dynamic Range ±450 ±480 °/sec

Sensitivity x_GYRO_OUT and x_GYRO_LOW (32-bit) 3.052 × 10−7 °/sec/LSB

Initial Sensitivity Tolerance ±1 %

Sensitivity Temperature Coefficient −40°C ≤ TA ≤ +70°C, 1 σ ±35 ppm/°C

Misalignment Axis-to-axis ±0.05 Degrees

Nonlinearity Best-fit straight line, FS = 450°/sec 0.01 % of FS

Initial Bias Error 1 σ ±0.2 °/sec

In-Run Bias Stability 1 σ 6.25 °/hr

Angular Random Walk 1 σ 0.3 °/√hr

Bias Temperature Coefficient −40°C ≤ TA ≤ +70°C, 1 σ ±0.0025 °/sec/°C

Output Noise No filtering 0.16 °/sec rms

Rate Noise Density f = 25 Hz, no filtering 0.0066 °/sec/√Hz rms

3 dB Bandwidth 330 Hz

Sensor Resonant Frequency 18 kHz

ACCELEROMETERS Each axis

Dynamic Range ±18

Sensitivity x_ACCL_OUT and x_ACCL_LOW (32-bit) 1.221 × 10−8 g/LSB

Sensitivity Temperature Coefficient −40°C ≤ TA ≤ +85°C, 1 σ ±25 ppm/°C

Misalignment Axis-to-axis ±0.035 Degrees

Axis-to-frame (package) ±1.0 Degrees

Nonlinearity Best-fit straight line, ±10 g 0.1 % of FS

Best-fit straight line, ±18 g 0.5 % of FS

In-Run Bias Stability 1 σ 0.1 mg

Velocity Random Walk 1 σ 0.029 m/sec/√hr

Bias Temperature Coefficient −40°C ≤ TA ≤ +85°C ±0.1 mg/°C

Output Noise No filtering 1.5 mg rms

Noise Density f = 25 Hz, no filtering 0.067 mg/√Hz rms

3 dB Bandwidth 330 Hz

Sensor Resonant Frequency 5.5 kHz

Dynamic Range

Sensitivity

Initial Sensitivity Tolerance

Sensitivity Temperature Coefficient

Misalignment Axis to axis 0.25 Degrees

Axis to frame (package) 0.5 Degrees

Nonlinearity Best fit straight line 0.5 % of FS

Initial Bias Error 0 gauss stimulus ±15 mgauss

Bias Temperature Coefficient −40°C ≤ TA ≤ +85°C, 1 σ 0.3 mgauss/°C

Output Noise

Noise Density

3 dB Bandwidth 330 Hz

±2.5 gauss

0.1 mgauss/LSB ±2 % 1 σ 275 ppm/°C

No filtering f = 25 Hz, no filtering

0.45 mgauss

0.054 mgauss/√Hz

Rev. B | Page 3 of 36

ADIS16488 Data Sheet

Error with Supply

0.04 %/V

Noise

0.025

mbar rms

Input Capacitance, CIN

10 pF

Output Low Voltage, VOL

= 2.0 mA

0.4

Power-down mode, VDD = 3.3 V

45 µA

Parameter Test Conditions/Comments Min Typ Max Unit

BAROMETER

Pressure Range 300 1100 mbar

Extended 10 1200 mbar

Sensitivity BAROM_OUT and BAROM_LOW (32-bit) 6.1 × 10−7 mbar/LSB

Total Error 4.5 mbar Relative Error1 −40°C to +85°C 2.5 mbar Linearity2 Best fit straight line, FS = 1100 mbar 0.1 % of FS

−40°C to +85°C 0.2 % of FS

Linear-g Sensitivity ±1 g, 1 σ 0.005 mbar/g

TEMPERATURE SENSOR

Scale Factor Output = 0x0000 at 25°C (±5°C) 0.00565 °C/LSB

LOGIC INPUTS3

Input High Voltage, VIH 2.0 V Input Low Voltage, VIL 0.8 V CS Wake-Up Pulse Width Logic 1 Input Current, IIH VIH = 3.3 V 10 µA Logic 0 Input Current, IIL VIL = 0 V

All Pins Except RST RST Pin

20 µs

10 µA

0.33 mA

DIGITAL OUTPUTS

Output High Voltage, VOH I

= 0.5 mA 2.4 V

SOURCE

SINK

FLASH MEMORY Endurance4 100,000 Cycles

Data Retention5 TJ = 85°C 20 Ye ars

FUNCTIONAL TIMES6 Time until data is available

Power-On Start-up Time 500 ms Reset Recovery Time 500 ms Sleep Mode Recovery Time 500 µs Flash Memory Update Time 375 ms Flash Memory Test Time 50 ms Automatic Self-Test Time Using internal clock, 100 SPS 12 ms

CONVERSION RATE 2.46 kSPS

Initial Clock Accuracy 0.02 % Temperature Coefficient 40 ppm/°C Sync Input Clock 0.77 2.4 kHz

POWER SUPPLY, VDD Operating voltage range 3.0 3.6 V

Power Supply Current8 Normal mode, VDD = 3.3 V, µ ± σ 254 mA Sleep mode, VDD = 3.3 V 12.2 mA

POWER SUPPLY, VDDRTC Operating voltage range 3.0 3.6 V

Real-Time Clock Supply Current Normal mode, VDDRTC = 3.3 V 13 µA

The relative error assumes that the initial error, at 25°C, is corrected in the end application.

Linearity errors assume a full scale (FS) of 1000 mbar.

The digital I/O signals are driven by an internal 3.3 V supply, and the inputs are 5 V tolerant.

Endurance is qualified as per JEDEC Standard 22, Method A117, and measured at −40°C, +25°C, +85°C, and +125°C.

The data retention specification assumes a junction temperature (TJ) of 85°C as per JEDEC Standard 22, Method A117. Data retention lifetime decreases with TJ.

These times do not include thermal settling and internal filter response times, which may affect overall accuracy.

Device functions at clock rates below 0.7 kHz, but at reduced performance levels.

Supply current transients can reach 450 mA for 400 µs during start-up and reset recovery.

Rev. B | Page 4 of 36

Data Sheet ADIS16488

Serial clock high period

DIN setup time before SCLK rising edge

SCLK

DOUT

DIN

1 2 3 4 5 6 15 16

R/W A5A6 A4 A3 A2

MSB

DB14

D1 LSB

DB13 DB12 DB10DB11 DB2 LSBDB1

DSHI

DAV

CHS

CLS

DSOE

DHD

DSU

10277-002

SCLK

STALL

10277-003

SYNC

CLOCK (CLKIN)

DATA

READY

OUTPUT

REGISTERS

10277-004

DATA VALID DATA VALID

TIMING SPECIFICATIONS

TA = 25°C, VDD = 3.3 V, unless otherwise noted.

Table 2.

Normal Mode Parameter Description Min1 Typ Max1 Unit

Serial clock 0.01 15 MHz

SCLK

Stall period between data 2 µs

STA LL

Serial clock low period 31 ns

CLS

CHS

tCS Chip select to clock edge 32 ns t

DOUT valid after SCLK edge 10 ns

DAV

DSU

DIN hold time after SCLK rising edge 2 ns

DHD

tDR, tDF DOUT rise/fall times, ≤100 pF loading 3 8 ns t

DSOE

CS assertion to data out active tHD SCLK edge to data out invalid 0 ns t

DSHI

Guaranteed by design and characterization, but not tested in production.

CS deassertion to data out high impedance

Input sync pulse width 5 µs

Input sync to data-ready output 490 µs

Input sync period 417 µs

0 11 ns

0 9 ns

Timing Diagrams

Figure 2. SPI Timing and Sequence

Figure 3. Stall Time and Data Rate

Figure 4. Input Clock Timing Diagram

Rev. B | Page 5 of 36

ADIS16488 Data Sheet

Any Axis, Unpowered

2000 g

Storage Temperature Range

−65°C to +150°C

24-Lead Module (ML-24-6)

22.8°C/W

10.1°C/W

48 g

ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Acceleration

Any Axis, Powered 2000 g VDD to GND −0.3 V to +3.6 V Digital Input Voltage to GND −0.3 V to VDD + 0.2 V Digital Output Voltage to GND −0.3 V to VDD + 0.2 V Operating Temperature Range −40°C to +85°C

Barometric Pressure 6 bar

Extended exposure to temperatures that are lower than −40°C or higher

than +105°C can adversely affect the accuracy of the factory calibration.

Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Table 4. Package Characteristics

Device

Package Type θJA θJC

Weight

ESD CAUTION

Rev. B | Page 6 of 36

Data Sheet ADIS16488

DIO3

SCLK

DIN

DIO1

DIO2

VDD

GND

DNC

VDDRTC

DIO4

DOUT

RST

VDD

GND

DNC

3456789

ADIS16488

TOP VIEW

(Not to S cale)

NOTES

1. THIS REPRESENTATION DISPLAYS T HE TOP VIEW PINOUT FOR THE MATING SO CKE T CONNECTOR.

2. THE ACTUAL CONNEC TO R P INS ARE NOT VISIBLE FROM THE TOP VIEW.

3. MATING CONNECTOR: SAMTEC CLM-112-02 OR EQUIVALENT.

4. DNC = DO NOT CONNECT TO THESE PINS.

10277-005

10277-006

PIN 1

PIN 23

DIO4

Input/output

Configurable Digital Input/Output.

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

Figure 5. Mating Connector Pin Assignments

Figure 6. Axial Orientation (Top Side Facing Up)

Table 5. Pin Function Descriptions

Pin No. Mnemonic Type Description

1 DIO3 Input/output Configurable Digital Input/Output.

3 SCLK Input SPI Serial Clock. 4 DOUT Output SPI Data Output. Clocks output on SCLK falling edge. 5 DIN Input SPI Data Input. Clocks input on SCLK rising edge. 6

Input SPI Chip Select.

7 DIO1 Input/output Configurable Digital Input/Output. 8

RST

Input Reset. 9 DIO2 Input/output Configurable Digital Input/Output. 10, 11, 12 VDD Supply Power Supply. 13, 14, 15 GND Supply Power Ground. 16 to 22, 24 DNC Not applicable Do Not Connect to These Pins. 23 VDDRTC Supply Real-Time Clock Power Supply.

Rev. B | Page 7 of 36

ADIS16488 Data Sheet

1000

100

0.01 0.1 1 10 100 1000 10000

ROOT AL LAN VARIANCE (° /Hour)

INTEGRATION PERIOD (Seconds)

10277-007

+1σ

–1σ

AVERAGE

0.001

0.00001

0.0001

0.01 0.1 1 10 100 1000 10000

ROOT AL LAN VARIANCE (g)

INTEGRATION PERIOD (Seconds)

10277-008

+1σ

–1σ

AVERAGE

0.8

–0.8

–0.6

–0.4

–0.2

0.2

0.4

0.6

–40 –30 –20 –10 0 10 20 30 40 50 60 70 80

GYRO SCAL E E RROR (% FS)

TEMPERATURE (°C)

10277-109

INITI AL ERROR = ±0.5% TEMPCO = 35ppm/°C

0.6

–0.6

–0.5

–0.4

–0.3

–0.2

–0.1

0.1

0.2

0.3

0.4

0.5

–40 –30 –20 –10 0 10 20 30 40 50

60 70 80

GYRO BIAS E RROR (°/sec)

TEMPERATURE (°C)

10277-110

INITI AL ERROR = ±0.2°/sec TEMPCO = 0.0025°/sec/°C

TYPICAL PERFORMANCE CHARACTERISTICS

Figure 7. Gyroscope Allan Variance, 25°C

Figure 8. Accelerometer Allan Variance, 25°C

Figure 9. Gyroscope Scale (Sensitivity) Error and Hysteresis vs. Temperature

Figure 10. Gyroscope Bias Error and Hysteresis vs. Temperature

Rev. B | Page 8 of 36

Data Sheet ADIS16488

BASIC OPERATION

The ADIS16488 is an autonomous sensor system that starts up on its own when it has a valid power supply. After running through its initialization process, it begins sampling, processing, and loading calibrated sensor data into the output registers, which are accessible using the SPI port. The SPI port typically connects to a compatible port on an embedded processor, using the connection diagram in Figure 11. The four SPI signals facilitate synchronous, serial data communication. Connect

RST

(see Table 5) to VDD or leave it open for normal operation. The factory default configuration provides users with a data-ready signal on the DIO2 pin, which pulses high when new data is available in the output data registers.

VDD

SYSTEM PROCESSOR SPI MASTER

I/O LINES ARE COMPATIBLE WITH

3.3V LOGIC LEVELS

SCLK

MOSI MISO

IRQ DIO2

Figure 11. Electrical Connection Diagram

CS SCLK DIN DOUT

13 14 15

+3.3V

11 12 23

ADIS16488

10277-009

Table 6. Generic Master Processor Pin Names and Functions

Mnemonic Function

Slave select IRQ Interrupt request MOSI Master output, slave input MISO Master input, slave output SCLK Serial clock

Embedded processors typically use control registers to configure their serial ports for communicating with SPI slave devices such as the ADIS16488. Table 7 provides a list of settings, which describe the SPI protocol of the ADIS16488. The initialization routine of the master processor typically establishes these settings using firmware commands to write them into its serial control registers.

Table 7. Generic Master Processor SPI Settings

Processor Setting Description

Master The ADIS16488 operates as a slave. SCLK ≤ 15 MHz Maximum serial clock rate. SPI Mode 3 CPOL = 1 (polarity), and CPHA = 1 (phase). MSB-First Mode Bit sequence. 16-Bit Mode Shift register/data length.

REGISTER STRUCTURE

The register structure and SPI port provide a bridge between the sensor processing system and an external, master processor. It contains both output data and control registers. The output data registers include the latest sensor data, a real-time clock, error flags, alarm flags, and identification data. The control registers include sample rate, filtering, input/output, alarms, calibration, and diagnostic configuration options. All communication between the ADIS16488 and an external processor involves either reading or writing to one of the user registers.

TRIAXIS

GYRO

TRIAXIS

ACCEL

TRIAXIS

MAGN BARO

TEMP

SENSOR

CONTROLLER

Figure 12. Basic Operation

DSP

The register structure uses a paged addressing scheme that is composed of 13 pages, with each one containing 64 register locations. Each register is 16 bits wide, with each byte having its own unique address within that page’s memory map. The SPI port has access to one page at a time, using the bit sequence in Figure 17. Select the page to activate for SPI access by writing its code to the PAGE_ID register. Read the PAGE_ID register to determine which page is currently active. Table 8 displays the PAGE_ID contents for each page, along with their basic functions. The PAGE_ID register is located at Address 0x00 on every page.

Table 8. User Register Page Assignments

Page PAGE_ID Function

0 0x00 Output data, clock, identification 1 0x01 Reserved 2 0x02 Calibration 3 0x03 Control: sample rate, filtering, I/O, alarms 4 0x04 Serial number 5 0x05 FIR Filter Bank A Coefficient 0 to Coefficient 59 6 0x06 FIR Filter Bank A, Coefficient 60 to Coefficient 119 7 0x07 FIR Filter Bank B, Coefficient 0 to Coefficient 59 8 0x08 FIR Filter Bank B, Coefficient 60 to Coefficient 119 9 0x09 FIR Filter Bank C, Coefficient 0 to Coefficient 59 10 0x0A FIR Filter Bank C, Coefficient 60 to Coefficient 119 11 0x0B FIR Filter Bank D, Coefficient 0 to Coefficient 59 12 0x0C FIR Filter Bank D, Coefficient 60 to Coefficient 119

OUTPUT

REGISTERS

CONTROL

REGISTERS

SPI

10277-010

Rev. B | Page 9 of 36

ADIS16488 Data Sheet

10277-011

SCLK

DIN

DIN = 1000 0000 0000 0011 = 0x8003, WRITES 0x03 TO ADDRESS 0x00

NONVOLATILE

FLASH MEMORY

(NO SPI ACCESS)

MANUAL

FLASH

BACKUP

START-UP

RESET

VOLATILE

SRAM

SPI ACCESS

10277-012

DIN

DOUT

0x1A00 0x1800

ADDRESS

Z_GYRO_OUT Z_GYRO_LOW

10277-013

SCLK

DIN

DOUT

DOUT = 0100 0000 0110 1000 = 0x4068 = 16, 488 ( P ROD_ID)

DIN = 0111 1110 0000 0000 = 0x7E00

10277-014

10277-015

R/W

A6 A5 A4 A3 A2 A1 A0 DC7 DC6 DC5 DC4 DC3 DC2 DC1 DC0

D0D1D2D3D4D5D6D7D8D9D10D11D12D13D14D15

SCLK

DIN

DOUT

A6 A5

D13D14D15

NOTES

1. DOUT BITS ARE PRO DUCE D ONLY WHEN THE PREVIOUS 16-BIT DI N S E QUENCE START S WITH R/W = 0.

2. WHEN CS IS HIGH, DOUT IS IN A THREE-STATE, HIGH IMPEDANCE MODE, WHICH ALLOWS MULTIFUNCTIONAL USE OF THE LINE FOR OT HE R DE V ICES.

SPI COMMUNICATION

The SPI port supports full duplex communication, as shown in Figure 17, which enables external processors to write to DIN while reading DOUT, if the previous command was a read request. Figure 17 provides a guideline for the bit coding on both DIN and DOUT.

DEVICE CONFIGURATION

The SPI provides write access to the control registers, one byte at a time, using the bit assignments shown in Figure 17. Each register has 16 bits, where Bits[7:0] represent the lower address (listed in Tabl e 9) and Bits[15:8] represent the upper address. Write to the lower byte of a register first, followed by a write to its upper byte second. The only register that changes with a single write to its lower byte is the PAGE_ID register. For a write command, the first bit in the DIN sequence is set to 1. Address Bits[A6:A0] represent the target address, and Data Command Bits[DC7:DC0] represent the data being written to the location. Figure 13 provides an example of writing 0x03 to Address 0x00 (PAG E_ I D [7:0]), using DIN = 0x8003. This write command activates the control page for SPI access.

Figure 13. SPI Sequence for Activating the Control Page (DIN = 0x8003)

Dual Memory Structure

Writing configuration data to a control register updates its SRAM contents, which are volatile. After optimizing each relevant control register setting in a system, use the manual flash update command, which is located in GLOB_CMD[3] on Page 3 of the register map. Activate the manual flash update command by turning to Page 3 (DIN = 0x8003) and setting GLOB_CMD[3] = 1 (DIN = 0x8208, then DIN = 0x8300). Make sure that the power supply is within specification for the entire 375 ms processing time for a flash memory update. Ta b le 9 provides a memory map for all of the user registers, which includes a column of flash backup information. A yes in this column indicates that a register has a mirror location in flash and, when backed up properly, automatically restores itself during startup or after a reset. Figure 14 provides a diagram of the dual memory structure used to manage operation and store critical user settings.

Figure 14. SRAM and Flash Memory Diagram

READING SENSOR DATA

The ADIS16488 automatically starts up and activates Page 0 for data register access. Write 0x00 to the PAGE_ID register (DIN = 0x8000) to activate Page 0 for data access after accessing any other page. A single register read requires two 16-bit SPI cycles. The first cycle requests the contents of a register using the bit assignments in Figure 17, and then the register contents follow DOUT during the second sequence. The first bit in a DIN command is zero, followed by either the upper or lower address for the register. The last eight bits are don’t care, but the SPI requires the full set of 16 SCLKs to receive the request. Figure 15 includes two register reads in succession, which starts with DIN = 0x1A00 to request the contents of the Z_GYRO_OUT register and follows with 0x1800 to request the contents of the Z_GYRO_LOW register.

Figure 15. SPI Read Example

Figure 16 provides an example of the four SPI signals when reading PROD_ID in a repeating pattern. This is a good pattern to use for troubleshooting the SPI interface setup and communications because the contents of PROD_ID are predefined and stable.

Figure 16. SPI Read Example, Second 16-Bit Sequence

Figure 17. SPI Communication Bit Sequence

Rev. B | Page 10 of 36

Data Sheet ADIS16488

Name

R/W

Flash

PAGE_ID

Address

Default

Format

Reserved

N/A

0x00

0x02 to 0x04

N/A

Reserved

N/A

X_GYRO_LOW

0x00

0x10

N/A

Output, x-axis gyroscope, low word

Table 14

X_ACCL_LOW

0x00

0x1C

N/A

Output, x-axis accelerometer, low word

Table 21

Z_ACCL_OUT

0x00

0x26

N/A

Output, z-axis accelerometer, high word

Table 19

Reserved

N/A

0x00

0x32 to 0x3E

N/A

Reserved

N/A

Z_DELTVEL_LOW

0x00

0x54

N/A

Output, z-axis delta velocity, low word

Table 37

Y_GYRO_SCALE

R/W

Yes

0x02

0x06

0x0000

Calibration, scale, y-axis gyroscope

Table 72

USER REGISTERS

Table 9. User Register Memory Map (N/A = Not Applicable)

PAGE_ID R/W No 0x00 0x00 0x00 Page identifier N/A

SEQ_CNT R No 0x00 0x06 N/A Sequence counter Table 56 SYS_E_FLAG R No 0x00 0x08 0x0000 Output, system error flags Table 47 DIAG_STS R No 0x00 0x0A 0x0000 Output, self-test error flags Table 48 ALM_STS R No 0x00 0x0C 0x0000 Output, alarm error flags Table 49 TEMP_OUT R No 0x00 0x0E N/A Output, temperature Table 45

X_GYRO_OUT R No 0x00 0x12 N/A Output, x-axis gyroscope, high word Table 10 Y_GYRO_LOW R No 0x00 0x14 N/A Output, y-axis gyroscope, low word Table 15 Y_GYRO_OUT R No 0x00 0x16 N/A Output, y-axis gyroscope, high word Table 11 Z_GYRO_LOW R No 0x00 0x18 N/A Output, z-axis gyroscope, low word Table 16 Z_GYRO_OUT R No 0x00 0x1A N/A Output, z-axis gyroscope, high word Table 12

X_ACCL_OUT R No 0x00 0x1E N/A Output, x-axis accelerometer, high word Table 17 Y_ACCL_LOW R No 0x00 0x20 N/A Output, y-axis accelerometer, low word Table 22 Y_ACCL_OUT R No 0x00 0x22 N/A Output, y-axis accelerometer, high word Table 18 Z_ACCL_LOW R No 0x00 0x24 N/A Output, z-axis accelerometer, low word Table 23

X_MAGN_OUT R No 0x00 0x28 N/A Output, x-axis magnetometer, high word Table 38 Y_MAGN_OUT R No 0x00 0x2A N/A Output, y-axis magnetometer, high word Table 39 Z_MAGN_OUT R No 0x00 0x2C N/A Output, z-axis magnetometer, high word Table 40 BAROM_LOW R No 0x00 0x2E N/A Output, barometer, low word Table 44 BAROM_OUT R No 0x00 0x30 N/A Output, barometer, high word Table 42

X_DELTANG_LOW R No 0x00 0x40 N/A Output, x-axis delta angle, low word Table 28 X_DELTANG_OUT R No 0x00 0x42 N/A Output, x-axis delta angle, high word Table 24 Y_DELTANG_LOW R No 0x00 0x44 N/A Output, y-axis delta angle, low word Table 29 Y_DELTANG_OUT R No 0x00 0x46 N/A Output, y-axis delta angle, high word Table 25 Z_DELTANG_LOW R No 0x00 0x48 N/A Output, z-axis delta angle, low word Table 30 Z_DELTANG_OUT R No 0x00 0x4A N/A Output, z-axis delta angle, high word Table 26 X_DELTVEL_LOW R No 0x00 0x4C N/A Output, x-axis delta velocity, low word Table 35 X_DELTVEL_OUT R No 0x00 0x4E N/A Output, x-axis delta velocity, high word Table 31 Y_DELTVEL_LOW R No 0x00 0x50 N/A Output, y-axis delta velocity, low word Table 36 Y_DELTVEL_OUT R No 0x00 0x52 N/A Output, y-axis delta velocity, high word Table 32

Z_DELTVEL_OUT R No 0x00 0x56 N/A Output, z-axis delta velocity, high word Table 33 Reserved N/A N/A 0x00 0x58 to 0x76 N/A Reserved N/A TIME_MS_OUT R Yes 0x00 0x78 N/A Factory configuration time: minutes/seconds Table 124 TIME_DH_OUT R Yes 0x00 0x7A N/A Factory configuration date/time: day/hour Table 125 TIME_YM_OUT R Yes 0x00 0x7C N/A Factory configuration date: year/month Table 126 PROD_ID R Yes 0x00 0x7E 0x4068 Output, product identification (16,488) Table 53 Reserved N/A N/A 0x01 0x00 to 0x7E N/A Reserved N/A PAGE_ID R/W No 0x02 0x00 0x00 Page identifier N/A Reserved N/A N/A 0x02 0x02 N/A Reserved N/A X_GYRO_SCALE R/W Yes 0x02 0x04 0x0000 Calibration, scale, x-axis gyroscope Table 71

Z_GYRO_SCALE R/W Yes 0x02 0x08 0x0000 Calibration, scale, z-axis gyroscope Table 73 X_ACCL_SCALE R/W Yes 0x02 0x0A 0x0000 Calibration, scale, x-axis accelerometer Table 81 Y_ACCL_SCALE R/W Yes 0x02 0x0C 0x0000 Calibration, scale, y-axis accelerometer Table 82 Z_ACCL_SCALE R/W Yes 0x02 0x0E 0x0000 Calibration, scale, z-axis accelerometer Table 83

Rev. B | Page 11 of 36

+ 25 hidden pages

ANALOG DEVICES ADIS16488 Service Manual

FEATURES

GENERAL DESCRIPTION

APPLICATIONS

FUNCTIONAL BLOCK DIAGRAM

TABLE OF CONTENTS

REVISION HISTORY

SPECIFICATIONS

TIMING SPECIFICATIONS

Timing Diagrams

ABSOLUTE MAXIMUM RATINGS

ESD CAUTION

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

TYPICAL PERFORMANCE CHARACTERISTICS

BASIC OPERATION

REGISTER STRUCTURE

SPI COMMUNICATION

DEVICE CONFIGURATION

Dual Memory Structure

READING SENSOR DATA

USER REGISTERS