Datasheet

REV. A
AD7719
–25–
Table XVI. IOCON (I/O and Current Source Control Register) Bit Designations
Bit Bit
Location Name Description
IOCON15 PSW2 Power Switch 2 Control Bit.
Set by user to enable power switch P2 to PWRGND.
Cleared by user to enable use as a standard I/O pin.
When the ADC is in standby mode, the power switches are open.
IOCON14 PSW1 Power Switch 1 Control Bit.
Set by user to enable power switch P1 to PWRGND.
Cleared by user to enable use as a standard I/O pin.
When ADC is in standby mode, the power switches are open.
IOCON13 0 This bit must be zero for correct operation.
IOCON12 BO Burnout Current Enable Bit.
Set by user to enable the 100 nA current sources in the main ADC signal path. A 100 nA current source is
applied to the positive input leg while a 100 nA sink is applied to the negative input.
Cleared by user to disable both transducer burnout current sources.
IOCON11 I2PIN IEXE2, 200 µA Current Source Direction Bit.
Set by user to enable IEXC2 current source to IOUT1.
Cleared by user to enable IEXC2 current source to IOUT2.
IOCON10 I1PIN IEXE1, 200 µA Current Source Direction Bit.
Set by user to enable IEXC1 current source to IOUT2.
Cleared by user to enable IEXC1 current source to IOUT1.
IOCON9 I2EN IEXC2 Current Source Enable Bit.
Set by user to turn on the IEXC2 excitation current source.
Cleared by user to turn off the IEXC2 excitation current source.
IOCON8 I1EN IEXC1 Current Source Enable Bit.
Set by user to turn on the IEXC1 excitation current source.
Cleared by user to turn off the IEXC1 excitation current source.
IOCON7 P4DIR P4, I/O Direction Control Bit.
Set by user to enable P4 as an output.
Cleared by user to enable P4 as an input. There are weak active pull-ups internally when enabled as an input.
IOCON6 P3DIR P3, I/O Direction Control Bit.
Set by user to enable P3 as an output.
Cleared by user to enable P3 as an input. There are weak active pull-ups internally when enabled as an input.
IOCON5 P2EN P2 Digital Output Enable Bit.
Set by user to enable P2 as a regular digital output pin.
Cleared by user to three-state P2 output.
PSW2 takes precedence over P2EN.
IOCON4 P1EN P1 Digital Output Enable Bit.
Set by user to enable P1 as a regular digital output pin.
Cleared by user to three-state P1 output.
PSW1 takes precedence over P1EN.
IOCON3 P4DAT Digital I/O Port Data Bits.
IOCON2 P3DAT The readback values of these bits indicate the status of their respective pin when the I/O port is active as
IOCON1 P2DAT an input.
IOCON0 P1DAT The values written to these data bits appear at the output port when the I/O bits are enabled as outputs.
P2 and P1 are outputs only, so reading P2DAT and P1DAT will return what was last written to these bits.