Datasheet

AD7414/AD7415
Rev. F | Page 9 of 20
INTERNAL REGISTER STRUCTURE
The AD7414 has five internal registers, as shown in Figure 8.
Four are data registers, and one is an address pointer register.
SDA
SCL
TEMPERATURE
VALUE
REGISTER
CONFIGURATION
REGISTER
T
HIGH
REGISTER
T
LOW
REGISTER
D
A
T
A
ADDRESS
POINTER
REGISTER
SERIAL BUS INTERFACE
02463-008
Figure 8. AD7414 Register Structure
The AD7415 has three internal registers, as shown in Figure 9.
Two are data registers, and one is an address pointer register.
SDA
SCL
D
A
T
A
TEMPERATURE
VALUE
REGISTER
CONFIGURATION
REGISTER
ADDRESS
POINTER
REGISTER
02463-009
Figure 9. AD7415 Register Structure
Each data register has an address pointed to by the address
pointer register when communicating with it. The temperature
value register is the only data register that is read-only.
ADDRESS POINTER REGISTER
The address pointer register is an 8-bit register that stores an
address that points to one of the four data registers of the
AD7414 and one of the two data registers of the AD7415. The
first byte of every serial write operation to the AD7414/AD7415
is the address of one of the data registers, which is stored in the
address pointer register and selects the data register to which
subsequent data bytes are written. Only the 2 LSBs of this
register are used to select a data register.
Table 6. Address Pointer Register
P7 P6 P5 P4 P3 P2 P1 P0
0 0 0 0 0 0 Register Select
Table 7. AD7414 Register Address
P1 P0 Register
0 0 Temperature value register (read-only)
0 1 Configuration register (read/write)
1 0 T
HIGH
register (read/write)
1 1 T
LOW
register (read/write)
Table 8. AD7415 Register Address
P1 P0 Registers
0 0 Temperature value register (read-only)
0 1 Configuration register (read/write)
Table 9. AD7414 Configuration Register
D7 D6 D5 D4 D3 D2 D1 D0
PD FLTR
ALERT
EN
ALERT
POLARITY
ALERT
RESET
ONE
SHOT
TEST
MODE
0
1
1
1
0
1
0
1
0
1
0
1
0s
1
1
Default settings at power-up.
CONFIGURATION REGISTER (ADDRESS 0X01)
The configuration register is an 8-bit read/write register that is
used to set the operating modes of the AD7414/AD7415. In the
AD7414, six of the MSBs are used (D7 to D2) to set the
operating modes (see Table 10). D0 and D1 are used for factory
settings and must have zeros written to them during normal
operation.
Table 10. AD7414 Configuration Register Settings
D7 Full power-down if = 1.
D6 Bypass SDA and SCL filtering if = 0.
D5 Disable ALERT if = 1.
D4 ALERT is active low if D4 = 0, ALERT is active high if D4 = 1.
D3
Reset the ALERT pin if set to 1. The next temperature
conversion has the ability to activate the ALERT function.
The bit status is not stored; thus this bit is 0 if read.
D2
Initiate a one shot temperature conversion if set to a 1.
The bit status is not stored; thus this bit is 0 if read.
Table 11. AD7415 Configuration Register
D7 D6 D5 D4 D3 D2 D1 D0
PD FLTR TEST MODE
0s
1
ONE SHOT TEST MODE
0
1
1
1
0s
1
0s
1
1
Default settings at power-up.