1.8 LM84 REGISTERS

1.8.1 COMMAND REGISTER

Selects which registers will be read from or written to. Data for this register should be transmitted during the Command Byte of

the SMBus write communication.

P7

P6

P5

P4

P3

P2

P1

P0

0000

Command Select

P0-P7: Command Select:

Command Se-

lect Address

Power On Default State

Register Name

Register Function

mal

00h

0000 0000

0

RLT

Read Local Temperature

01h

0000 0000

0

RRT

Read Remote Temperature

02h

0000 0000

0

RS

Read Status

03h

0000 0000

0

RC

Read Configuration

04h

0000 0000

0

RMID

Manufacturers ID

05h

0111 1111

127

RLCS

Read Local T_CRIT Setpoint

07h

0111 1111

127

RRCS

Read Remote T_CRIT

Setpoint

09h

0000 0000

0

WC

Write Configuration

0Bh

0111 1111

127

WLCS

Write Local T_CRIT Setpoint

0Dh

0111 1111

127

WRCS

Write Remote T_CRIT

Setpoint

1.8.2 LOCAL and REMOTE TEMPERATURE REGISTERS

(Read Only Address 00h and 01h):

D7

D6

D5

D4

D3

D2

D1

D0

MSB

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

LSB

D7–D0: Temperature Data. One LSB = 1˚C. Two’s complement format.

1.8.3 STATUS REGISTER

(Read Only Address 02h):

D7

D6

D5

D4

D3

D2

D1

D0

0

LTCRIT

0

RTCRIT

0

OPEN

0

0

Power up default is with all bits “0” (zero).

D2: OPEN: When set to 1 indicates a Remote Diode disconnect.

D4: RTCRIT: When set to 1 indicates an RT_CRIT alarm.

D6: LTCRIT: When set to 1 indicates an LT_CRIT alarm.

D7, D5, D3, D1–D0: These bits are always set to 0.

1.8.4 Manufacturers ID Register

(Read Address 04h) Default value 00h.

1.8.5 CONFIGURATION REGISTER

(Read Address 03h /Write Address 09h):

D7

D6

D5

D4

D3

D2

D1

D0

T_CRIT_A

mask

0000000

Power up default is with all bits “0” (zero).

D7: T_CRIT_A mask: When set to 1 T_CRIT_A interrupts are masked.

D6–D0: These bits are always set to 0. A write of 1 will return a 0 when read.

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