Data Sheet

ADIS16136

Rev. A | Page 9 of 20

OUTPUT DATA REGISTERS

Table 8. Output Data Register Formats

Register

Address

Measurement

TEMP_OUT

0x02

Internal temperature

GYRO_OUT2

0x04

Gyroscope, lower 16 bits

GYRO_OUT

0x06

Gyroscope, upper 16 bits

Rotation Rate (Gyroscope)

GYRO_OUT is the primary register for gyroscope output data

and uses 16-bit twos complement format for its data. Table 9

provides the numerical format, and Table 10 provides several

examples for converting digital data into °/sec.

Table 9. GYRO_OUT Bit Descriptions

Bits

Description

[15:0]

Gyroscope data; twos complement, 0.018275°/sec per

LSB, 0°/sec = 0x0000

Table 10. GYRO_OUT, Twos Complement Format

Rotation Rate

Decimal

Hex

Binary

+450°/sec

+24,623

0x602F

0110 0000 0010 1111

+0.03655°/sec

+2

0x0002

0000 0000 0000 0010

+0.018275°/sec

+1

0x0001

0000 0000 0000 0001

0°/sec

0

0x0000

0000 0000 0000 0000

−0.018275°/sec

−1

0xFFFF

1111 1111 1111 1111

−0.03655°/sec

−2

0xFFFE

1111 1111 1111 1110

−450°/sec

−24,623

0x9FD1

1001 1111 1101 0001

The GYRO_OUT2 register (see Table 11) captures the bit growth

associated with the decimation and FIR filters that are shown in

Figure 18 using a MSB justified format. The bit growth starts

with the MSB (GYRO_OUT2[15]), is equal to the decimation

rate setting in DEC_RATE[4:0] (see Table 18), and grows in the

LSB direction as the decimation rate increases. See Figure 14 for

more details.

Table 11. GYRO_OUT2 Bit Descriptions

Bits

Description

[15:0]

Rotation rate data; resolution enhancement bits

Figure 14. Gyroscope Output Format, DEC_RATE[4:0] > 0

Internal Temperature

The TEMP_OUT register (see Table 12) provides an internal

temperature measurement that can be useful for observing

relative temperature changes in the environment. Table 13

provides several coding examples for converting the 16-bit

twos complement number into units for temperature (°C).

Table 12. TEMP_OUT Bit Descriptions

Bits

Description

[15:0]

Temperature data; twos complement, 0.010697°C per

LSB, 0°C = 0x0000

Table 13. Temperature, Twos Complement Format

Temperature

Decimal

Hex

Binary

+85°C

+7946

0x1F0A

0001 1111 0000 1010

+0.021394°C

+2

0x0002

0000 0000 0000 0010

+0.010697°C

+1

0x0001

0000 0000 0000 0001

0°C

0

0x0000

0000 0000 0000 0000

−0.010697 °C

−1

0xFFFF

1111 1111 1111 1111

−0.021394°C

−2

0xFFFE

1111 1111 1111 1110

−40°C

−3739

0xF165

1111 0001 0110 0101

DEVICE CONFIGURATION

The control registers listed in Table 14 provide a variety of user

configuration options. The SPI provides access to these registers,

one byte at a time, using the bit assignments shown in Figure 13.

Each register has 16 bits, wherein Bits[7:0] represent the lower

address and Bits[15:8] represent the upper address.

Figure 15 provides an example of writing 0x03 to Address 0x22

(DEC_RATE[7:0]), using Pin 5, DIN = 0xA203. This example

reduces the sample rate by a factor of 8 (see Table 16).

Figure 15. SPI Sequence for Setting the Decimate Rate to 8 (DIN = 0xA203)

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, set GLOB_CMD[3] = 1 (DIN =

0xA808) to backup these settings in the nonvolatile flash memory.

The flash back up process requires a valid power supply level for

the entire 72 ms process time. Table 14 provides a user register

memory map that 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 16 provides a diagram of the

dual memory structure that is used to manage operation and store

critical user settings.

Figure 16. SRAM and Flash Memory Diagram

GYROSCOPE DATA

NOT USED

D

15

0 15

0

D = DEC_RATE[4:0]

BIT WEIGHT =

0.018275

LSB = GYRO_OUT2[16-D]

°/sec

LSB

GYRO_OUT

GYRO_OUT2

DIN = 1010 0010 0000 0011 = 0xA203, WRITES 0x03 TO ADDRESS 0x22

SCLK

DIN

CS

NONVOLATILE

FLASH MEMORY

(NO SPI ACCESS)

MANUAL

FLASH

BACKUP

START-UP

RESET

VOLATILE

SRAM

SPI ACCESS