THMC10

REMOTE/LOCAL TEMPERATURE MONITOR

WITH SMBus INTERFACE

SLIS089 – DECEMBER 1999

9

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

SMBus registers and addresses (continued)

Table 3. Address Pointer Register Map

REGISTER

ADDRESS

POINTER

POR STATE

FUNCTION

RIT

00h

0000 0000†

Read internal temperature

RET

01h

0000 0000†

Read external temperature

RS

02h

0000 0000

Read status byte

RC

03h

0000 0000

Read configuration byte

RCR

04h

0000 0010

Read acquisition rate byte

RIHL

05h

0111 1111

Read internal high limit

RILL

06h

1100 1001

Read internal low limit

REHL

07h

0111 1111

Read external high limit

RELL

08h

1100 1001

Read external low limit

WC

09h

N/A

Write configuration byte

WCR

0Ah

N/A

Write acquisition rate byte

WIHL

0Bh

N/A

Write internal high threshold

WILL

0Ch

N/A

Write internal low threshold

WEHL

0Dh

N/A

Write external high threshold

WELL

0Eh

N/A

Write external low threshold

OSHT

0Fh

N/A

One-shot (uses send byte format)

MFG ID

FEh

0100 1001

Read manufacturer ID (0

×49 for TI)

REV ID

FFh

N/A

Read silicon revision number

† If the THMC10 is in standby

Table 4. Configuration Register Bit Assignments

BIT

NAME

POR STATE

FUNCTION

7 (MSB)

MASK

0

Masks ALERT interrupts if high.

6

Run/stop

0

Standby mode control bit, if high, standby mode is initiated. (Note: Does not disable SMBus Interface)

5 to 0

Reserved

Table 5. Status Register Bit Assignments

BIT

NAME

POR STATE

FUNCTION

7 (MSB)

BUSY

0

A/D is busy acquiring when high.

6

LHIGH†

0

Internal high-temperature alarm has tripped when high, cleared by power-on reset (POR) or readout of

entire status byte.

5

LLOW†

0

Internal low-temperature alarm has tripped when high, cleared by POR or readout of entire status byte.

4

RHIGH†

0

External high-temperature alarm has tripped when high, cleared by POR or readout of entire status byte.

3

RLOW†

0

External low-temperature alarm has tripped when high, cleared by POR or readout of entire status byte.

2

OPEN†

0

A high indicates an external diode open.

1 to 0

0

Reserved

† These flags stay high until cleared by POR or until the status byte register is read.