Datasheet AD7854, AD7854L (Analog Devices) - 10

AD7854/AD7854L STATUS REGISTER
The arrangement of the status register is shown below. The status register is a read-only register and contains 16 bits of data. The status register is selected by writing to the control register and putting two 1s in RDSLT1 and RDSLT0. The function of the bits in the status register are described below. The power-up status of all bits is 0.
START WRITE TO CONTROL REGISTER SETTING RDSLT0 = RDSLT1 = 1 READ STATUS REGISTER
Figure 4. Flowchart for Reading the Status Register
MSB
ZERO ZERO ZERO ZERO ZERO ZERO PMGT1 PMGT0 ONE ONE AMODE BUSY CALMD CALSLT1 CALSLT0 STCAL
LSB Status Register Bit Function Description Bit Mnemonic Comment
15 ZERO These six bits are always 0. 14 ZERO 13 ZERO 12 ZERO 11 ZERO 10 ZERO 9 PMGT1 Power Management Bits. These bits will indicate if the part is in a power-down mode or not. See Table VI 8 PMGT0 in Power-Down Section for description. 7 ONE Both these bits are always 1. 6 ONE 5 AMODE Analog Mode Bit. When this bit is a 0, the device is set up for the unipolar analog input range. When this bit is a 1, the device is set up for the bipolar analog input range. 4 BUSY Conversion/Calibration Busy Bit. When this bit is 1, this indicates that there is a conversion or calibration in progress. When this bit is 0, there is no conversion or calibration in progress. 3 CALMD Calibration Mode Bit. A 0 in this bit indicates a self-calibration is selected, and a 1 in this bit indicates a system calibration is selected (see Table III). 2 CALSLT1 Calibration Selection Bits and Start Calibration Bit. The STCAL bit is read as a 1 if a calibration is in 1 CALSLT0 progress and as a 0 if there is no calibration in progress. The CALSLT1 and CALSLT0 bits indicate 0 STCAL which of the calibration registers are addressed for reading and writing (see section on the Calibration Registers for more details). –10– REV. B