Calibration Byte (55h)

S

P

0

0

A0

A1

A2

A3

A4

S

P

0

G/nI R/nW C/nA

Command and Address Phase

S

P

Data Byte 2

D8

D9

D10

D11 D12 D13 D14 D15

S

P

Data Byte 1

D0

D1

D2

D3

D4

D5

D6

D7

Register Pointer Phase

0

1

0

1

P0

P1

P2

P3

P

S

P

1

0

1

0

1

0

1

0

S

P

1

0

1

1

0

1

0

1

G/nI R/nW C/nA AC0 AC1 AC2 AC3 AC4

1

0

1

0

1

0

1

0

S

P

S

P

1

1

0

1

0

1

0

1

G/nI R/nW C/nA AC0 AC1 AC2 AC3 AC4

S

P

Address Response Byte from Sensor N

1

0

1

A0

A1

A2

A3

A4

S

P

1

0

0

1

0

1

0

1

TMP107

SBOS716B – MAY 2015 – REVISED SEPTEMBER 2015

www.ti.com

7.3.3.2.1.2

Last Device Poll

When the host issues a last-device-poll command, the last sensor on the initialized daisy chain responds back

with the last device address, as shown in Figure 24. The last-device-poll command is also used to check if the

daisy-chain address set is intact. If the daisy chain is not intact, the host does not receive a response to the last-

device-poll command. This command only works if the last device in the chain was the last device during

initialization. For example, if there are ten devices in the chain during address initialization and two devices are

removed, running this command does not provide the host with the address of device eight. Device eight was not

the last device during chain initialization, so it cannot report that device eight is the last device in the chain. In

this example, the command is not answered.

Figure 24. Last-Device-Poll Command

7.3.3.2.1.3

Global Software Reset

Use the global-software-reset command to issue a software reset to the chain in order for the devices to load the

power-on reset values from EEPROM and clear the temperature result register. This command performs the

same function as writing a 1 to RST (bit 1 in the configuration register). The sequence of this command is shown

in Figure 25.

Figure 25. Global Software Reset Command

7.3.3.2.2

Address Operations

7.3.3.2.2.1

Individual Write

Use the individual write operation to write data to a specific register in a specific device in the daisy chain, as

shown in Figure 26.

Figure 26. Individual Write Operation

18

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