Datasheet ADIS16480 (Analog Devices) - 2

ADIS16480 Silicon Anomaly Table 4. Incorrect Output Data String After Writing to the FNCTIO_CTRL Register [er004] Background
The FNCTIO_CTRL register provides user configuration control for the digital I/O pins, and the TEMP_OUT register provides the internal temperature measurement, which serves as an input to the inertial calibration outputs.
Issue
On units that have Firmware Revision 2.01 (or earlier), a write to the FNCTIO_CTRL register causes the TEMP_OUT variable to contain an incorrect value for 120 samples. Because this is an input to the calibration function for the gyroscopes and accelerometers, this issue causes the appearance of a discrete bias change between Sample 120 and Sample 121.
Workaround
When using units that have Firmware Revision 2.01 (or earlier), ignore the first 120 samples of the output registers after writing to the FNCTIO_CTRL register. Use the FIRM_REV register to determine the firmware revision of a unit. For example, FIRM_REV = 0x0201 equates to a firmware revision of 2.01.
Related Issues
None.
Table 5. Incorrect Offset and Scale Correction Order [er005] Background
Each accelerometer and gyroscope has unique user configurable offset and scale correction registers. For instance, on the x-axis gyroscope, the XG_BIAS_HIGH and XG_BIAS_LOW registers combine to provide the 32-bit, twos complement bias (offset) correction factor, and the X_GYRO_SCALE register provides the scale correction function. The proper order of applying these correction factors is bias correction first and scale correction second.
Issue
On units that have Firmware Revision 2.01 (or earlier), the order of application is reversed, and the ADIS16480 applies the scale correction value first, followed by the offset value.
Workaround
When using units that have firmware Revision 2.01 or earlier, if this function is part of the system-level calibration processes, note this difference. Use the FIRM_REV register to determine the firmware revision of a unit. For example, FIRM_REV = 0x0201 equates to a Firmware Revision 2.01.
Related Issues
None.
Table 6. Factory Restore Command in GLOB_CMD Not Working Properly [er006] Background
GLOB_CMD[6] provides a factory restore function that enables users to reset all user configurable calibration registers to 0x0000 (factory default). To activate this function, turn to Page 3 by setting DIN = 0x8003, and then set GLOB_CMD[6] = 1 by writing the following two 16-bit commands to the DIN line: 0x8240 and 0x8300.
Issue
On units that have Firmware Revision 2.03 (or earlier), setting GLOB_CMD[6] = 1 does not reset all calibration registers.
Workaround
When using units that have Firmware Revision 2.03 (or earlier), write 0x0000 to each individual calibration register. Use the FIRM_REV register to determine the firmware revision of a unit. For example, FIRM_REV = 0x0203 equates to a Firmware Revision 2.03.
Related Issues
None.
Table 7. EKF Setting Time and Accuracy Affected by Accidental Writes to Hidden Register [er007] Background
In the ADIS16480 data sheet, Address 0x0E on Page 3 is a reserved location. Although this location contains a valid user register for other products in this same family, it is not accessible through the serial peripheral interface (SPI) for users.
Issue
On units that have Firmware Revision 2.04 and earlier, this location is not write protected and can influence the extended Kalman filter (EKF) operation.
Workaround
On Page 3, write 0x04 to Address 0x0E and write 0x07 to Address 0x0F to restore proper EKF settling and operation. Note that the factory default is 0x070A for all devices that have Firmware Revision 2.04 and earlier. If this setting is providing proper service for a particular application, there is no need to change it. Ensure that this location does not experience any other write commands. The impact of moving from 0x070A to 0x0704 is that the EKF settling time is reduced from ~26 sec to ~416 ms.
Related Issues
None. Rev. 0 | Page 2 of 4 Document Outline FUNCTIONALITY ISSUES ANOMALY STATUS