EVAL-AD7719EB Analog Devices Inc, EVAL-AD7719EB Datasheet - Page 19

• Manufacturer Part Number: EVAL-AD7719EB
• Description: BOARD EVAL FOR AD7719
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7719EB

• Rohs Status: RoHS non-compliant
• Number Of Adc's: 2
• Number Of Bits: 24
• Sampling Rate (per Second): 105
• Data Interface: Serial
• Inputs Per Adc: 3 Single Ended
• Input Range: 2 Vpp
• Power (typ) @ Conditions: 4.85mW @ 105SPS
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7719

Communications Register (A3, A2, A1, A0 = 0, 0, 2, 0)
The Communications register is an 8-bit write-only register. All
communications to the part must start with a write operation to
the Communications register. The data written to the Commu-
nications register determines whether the next operation is a read
or write operation, and to which register this operation takes
place. For read or write operations, once the subsequent read or
write operation to the selected register is complete, the interface
returns to where it expects a write operation to the Communications
Bit
Location
CR7
CR6
CR5
CR4
CR3–CR0
REV. A
WEN (0)
CR7
Zero
Zero
A3–A0
R/W
Bit
Name
WEN
A3
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
R/W (0)
CR6
position indicates that the next operation will be a read from the designated register.
accessed during this serial interface communication. A3 is the MSB of the three selection bits.
Description
Write Enable Bit. A 0 must be written to this bit so the write operation to the Communications register
actually takes place. If a 1 is written to this bit, the part will not clock on to subsequent bits in the register.
It will stay at this bit location until a 0 is written to this bit. Once a 0 is written to the WEN bit, the next
seven bits will be loaded to the Communications register.
A 0 in this bit location indicates that the next operation will be a write to a specified register. A 1 in this
A 0 must be written to this bit position to ensure correct operation of the AD7719.
A 0 must be written to this bit position to ensure correct operation of the AD7719.
Register Address Bits. These address bits are used to select which of the AD7719’s registers is being
A2
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Table IX. Communications Register Bit Designations
A1
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
CR5
0 (0)
A0
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Table X. Register Selection Table
CR4
0 (0)
Register
Communications Register during a Write Operation
Status Register during a Read Operation
Mode Register
Main ADC Control Register (AD0CON)
Aux ADC Control Register (AD1CON)
Filter Register
Main ADC Data Register
Aux ADC Data Register
I/O Control Register
Main ADC Offset Calibration Register
Aux ADC Offset Calibration Register
Main ADC Gain Calibration Register
Aux ADC Gain Calibration Register
Test 1 Register
Test 2 Register
Undefined
ID Register
–19–
register. This is the default state of the interface, and on power-up
or after a RESET, the AD7719 is in this default state waiting for a
write operation to the Communications register. In situations where
the interface sequence is lost, a write operation of at least 32 serial
clock cycles with DIN high returns the AD7719 to this default
state by resetting the part. Table IX outlines the bit designations
for the Communications register. CR0 through CR7 indicate the
bit location, with CR denoting that the bits are in the Commu-
nications register. CR7 denotes the first bit of the data stream.
A3 (0)
CR3
A2 (0)
CR2
A1 (0)
CR1
A0 (0)
AD7719
CR0