AD7856KR-REEL Analog Devices Inc, AD7856KR-REEL Datasheet - Page 12

• Manufacturer Part Number: AD7856KR-REEL
• Description: IC ADC 14BIT 8CH 5V 24-SOIC
• Manufacturer: Analog Devices Inc

Specifications of AD7856KR-REEL

• Rohs Status: RoHS non-compliant
• Number Of Bits: 14
• Sampling Rate (per Second): 285k
• Data Interface: 8051, QSPI™, Serial, SPI™ µP
• Number Of Converters: 2
• Power Dissipation (max): 89.25mW
• Voltage Supply Source: Analog and Digital
• Operating Temperature: 0°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (0.300", 7.50mm Width)

AD7856
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 first 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.
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
LSB
MSB
RDSLT1
ZERO
ZERO
BUSY
PMGT1
PMGT0
RDSLT1
RDSLT0
2/3 MODE
X
CALMD
CALSLT1
CALSLT0
STCAL
SGL/DIFF
CH2
CH1
CH0
Mnemonic
RDSLT0
BUSY
This bit is always 0.
Conversion/Calibration Busy Bit. When this bit is 1 it indicates that there is a conversion or
calibration in progress. When this bit is 0, there is no conversion or calibration in progress.
These four bits indicate the channel which is selected for conversion (see Table III).
Power management bits. These bits, along with the SLEEP pin, will indicate if the part is in a
power-down mode or not. See Table VI for description.
Both of these bits are always 1, indicating it is the status register which is being read (see Table II).
Interface Mode Select Bit. With this bit at 0, the device is in Interface Mode 2. With this bit at 1,
the device is in Interface Mode 1. This bit is reset to 0 after every read cycle.
Don’t care bit.
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 IV).
Calibration Selection Bits and Start Calibration Bit. The STCAL bit is read as a 1 if a
calibration is in progress and as a 0 if there is no calibration in progress. The CALSLT1 and
CALSLT0 bits indicate which of the calibration registers are addressed for reading and writing
(see section on the Calibration Registers for more details).
Comment
SGL/DIFF
2/3 MODE
STATUS REGISTER BIT FUNCTION DESCRIPTION
Figure 6. Flowchart for Reading the Status Register
WRITE TO CONTROL REGISTER
SETTING RDSLT0 = RDSLT1 = 1
CH2
X
READ STATUS REGISTER
–12–
START
CALMD
CH1
CALSLT1
CH0
CALSLT0
PMGT1
PMGT0
STCAL
REV. A