ADIS16135

Rev. 0 | Page 15 of 20

Example I/O Configuration

For example, set GPIO_CTRL[7:0] = 0x02 (DIN = 0x9A02) to

set DIO1 as an input and DIO2 as an output. Then, set

GPIO_CTRL[15:8] = 0x02 (DIN = 0x9B02) to set DIO2 in a

high output state. Monitor DIO1 by reading GPIO_CTRL[8]

(DIN = 0x1B00).

Table 31. MSC_CTRL Bit Descriptions

Bits

Description (Default = 0x0006)

[15:12]

Not used

[11]

Memory test (cleared upon completion)

(1 = enabled, 0 = disabled)

[10]

Automatic self-test (cleared upon completion)

(1 = enabled, 0 = disabled)

[9]

Manual self-test

(1 = enabled, 0 = disabled)

[8]

Not used

[7]

Disable sensor compensation

(1 = disable compensation, 0 = enable compensation)

[6:3]

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 = DIO2, 0 = DIO1)

Table 32. GPIO_CTRL Bit Descriptions

Bits

Description (Default = 0x0000)

[15:10]

Don’t care

[9]

General-Purpose I/O Line 2 (DIO2) data level

[8]

General-Purpose I/O Line 1 (DIO1) data level

[7:2]

Don’t care

[1]

General-Purpose I/O Line 2 (DIO2) direction control

(1 = output, 0 = input)

[0]

General-Purpose I/O Line 1 (DIO1) direction control

(1 = output, 0 = input)

SELF-TEST

The MSC_CTRL bits (see Table 31) provide a self-test function,

which helps verify the mechanical integrity of the MEMS and

signal processing circuit. When enabled, the self-test applies an

electrostatic force to the internal sensor element, which causes it

to move in a manner that simulates its response to actual

rotation. There are two self-test options in the MSC_CTRL

register: automatic and manual. Set MSC_CTRL[10] = 1 (DIN

= 0x9D04) to run the automatic self-test routine, which reports

a pass/fail result in DIAG_STAT[5]. MSC_CTRL[10] resets

itself to 0 after completing this routine. This process takes

approximately 46 ms. Set MSC_CTRL[9] = 1 (DIN = 9D01) to

manually activate the self-test function, and set MSC_CTRL[9]

= 0 (DIN = 9D00) to manually deactivate the self-test function.

Measure the output bias for each condition, take the difference

between them, and compare it to the expected self-test response

shown in Table 1.

POWER MANAGEMENT

The SLP_CTRL register (see Table 33) provides two different

sleep modes for system-level management: normal and timed.

Set SLP_CTRL[7:0] = 0xFF (DIN = 0xA4FF) to start normal

sleep mode. To awaken the device from sleep mode, use one of

the following options to restore normal operation: assert CS

from high to low, pulse RST low, then high again, or cycle the

power. Use SLP_CTRL[7:0] to put the device into sleep mode

for a specified period. For example, SLP_CTRL[7:0] = 0x64

(DIN = 0xA464) puts the ADIS16135 to sleep for 50 sec.

Table 33. SLP_CTRL Bit Descriptions

Bits

Description

[15:8]

Not used

[7:0]

0xFF: normal sleep mode

0x00 to 0xFE: programmable sleep time bits; 0.5 sec/LSB

STATUS

The DIAG_STAT register (see Table 34) provides error flags for

a number of functions. Each flag uses a 1 to indicate an error

condition and a 0 to indicate a normal condition. Reading this

register provides access to each flag’s status and resets all of the

bits to 0 for monitoring future operation. If the error condition

remains, the error flag returns to 1 at the conclusion of the next

sample cycle. DIAG_STAT[0] does not require a read of this

register to return to 0. If the power supply voltage goes back

into range, this flag clears automatically. The SPI communication

error flag in DIAG_STAT[3] indicates that the number of

SCLKs in a SPI sequence did not equal a multiple of 16 SCLKs.

Table 34. DIAG_STAT Bit Descriptions

Bits

Description (Default = 0x0000)

[15:10]

Not used

[9]

Alarm 2 status (1 = active, 0 = inactive)

[8]

Alarm 1 status (1 = active, 0 = inactive)

[7]

Not used

[6]

Flash test, checksum flag (1 = fail, 0 = pass)

[5]

Self-test diagnostic error flag (1 = fail, 0 = pass)

[4]

Sensor over range (1 = over range, 0 = normal)

[3]

SPI communication failure (1 = fail, 0 = pass)

[2]

Flash update failure (1 = fail, 0 = pass)

[1]

Not used

[0]

Power supply low, (1 = VCC <4.75 V, 0 = VCC >4.75 V)