ADIS16260/ADIS16265

Rev. PrB | Page 16 of 19

STATUS AND DIAGNOSTICS

The ADIS16260/ADIS16265 provide a number of status and

diagnostic functions. Table 25 provides a summary of these

functions, along with their appropriate control registers.

Table 25. Status and Diagnostic Functions

Function

Register

Data-ready I/O indicator

MSC_CTRL

Self-test, mechanical check for MEMS sensor

MSC_CTRL

Status, check for predefined error conditions

STATUS

Flash memory endurance

ENDURANCE

Alarms, configure and check for user-specific

conditions

ALM_MAG1/2

ALM_SMPL1/2

ALM_CTRL

Data-Ready I/O Indicator

The data-ready function provides an indication of updated

output data. The MSC_CTRL register provides the opportunity

to configure either of the general-purpose I/O pins (DIO0 and

DIO1) as a data-ready indicator signal. After each output register

update, the digital I/O changes states, then returns to its original

state, creating a pulsed waveform. The duty cycle of that waveform

is in between 15% and 35%.

Table 26. MSC_CTRL Register Definition

Address

Default

Format

Access

0x35, 0x34

0x0000

N/A

R/W

Table 27. MSC_CTRL Bit Descriptions

Bit

Description

15:11

Not used

10

Internal self-test enable

1 = enabled

0 = disabled

9

External negative rotation self-test enable

1 = enabled

0 = disabled

8

External positive rotation self-test enable

1 = enabled

0 = disabled

7:3

Not used

2

Data-ready enable

1 = enabled

0 = disabled

1

Data-ready polarity

1 = active high

0 = active low

0

Data-ready line select

1 = DIO1

0 = DIO0

Self-Test

The MSC_CTRL register also provides a self-test function, which

verifies the MEMS sensor’s mechanical integrity. There are two

different self-test options: (1) internal self-test and (2) external

self-test. The internal test provides a simple, two-step process

for checking the MEMS sensor: (1) start the process by writing

a 1 to Bit 10 in the MSC_CTRL register and (2) check the result

by reading Bit 5 of the STATUS register, after 35 ms.

The external self-test is a static condition that can be enabled

and disabled. In this test, both positive and negative MEMS

sensor movements are available. After writing to the appropriate

control bit, the GYRO_OUT register reflects the changes after a

delay that reflects the sensor signal chain response time.

For example, the standard 52 Hz bandwidth reflects an

exponential response with a time constant of 3.2 ms. If the

bandwidth is reduced externally (capacitor across RATE and FILT)

or internally (increasing the number of filter taps, SENS/AVG),

this time constant increases. For the internal self-test option,

increasing the delay can produce false alarms, since the internal

timing for this function is optimized for maximum bandwidth.

The appropriate bit definitions for self-test are listed in Table 26

and Table 27.

Status Conditions

The STATUS register contains the following error-condition

flags: Alarm conditions, self-test status, angular rate over range,

SPI communication failure, control register update failure, and

power supply out of range. See Table 28 and Table 29 for the

appropriate register access and bit assignment for each flag.

The bits assigned for checking power supply range and angular

rate over range automatically reset to 0 when the error

condition no longer exists. The remaining error-flag bits in the

STATUS register require a read in order to return them to 0.

Note that a STATUS register read clears all of the bits to 0.

Table 28. STATUS Register Definition

Address

Default

Format

Access

0x3D, 0x3C

0x0000

N/A

Read-only

Table 29. STATUS Bit Descriptions

Bit

Description

15:10

Not used

9

Alarm 2 status

1 = active, 0 = inactive

8

Alarm 1 status

1 = active, 0 = inactive

7:6

Not used

5

Self-test diagnostic error flag

1 = error condition, 0 = normal operation

4

Angular rate over range

1 = error condition, 0 = normal operation

3

SPI communications failure

1 = error condition, 0 = normal operation

2

Control register update failed

1 = error condition, 0 = normal operation

1

Power supply above 5.25 V

1 = above 5.25 V, 0 = below 5.25 V (normal)

0

Power supply below 4.75 V

1 = below 4.75 V, 0 = above 4.75 V (normal)