1°C Triple SMBus Temperature Sensor

Datasheet

SMSC EMCT03

9

Revision 2.3 (04-19-05)

DATASHEET

During Power on Reset (POR), the default values are stored in the registers. A POR is initiated when

power is first applied to the part and the voltage on the VDD supply surpasses the POR level as

specified in the electrical characteristics. Any reads to undefined registers will return 00h. Writes to any

undefined registers will not have an effect.

The EMCT03 uses an interlock mechanism that prevents changes in register content when fresh

readings come in from the ADC during successive reads from a host. When the High Byte is read, the

last conversion value is latched into the High Byte and Low Byte. Please note that the interlock

mechanism is only effective when reading the High Byte first.

3.4

Temperature Monitor Registers

As shown in Table 3.4, each temperature monitor has two byte wide data registers. The external

monitors are equipped with both legacy and extended data format. The 11 bit data temperature is

stored aligned to the left resulting in the High Byte to contain temperature in 1

°C steps and the Low

Byte to contain fractions of

°C as outlined below:

FAh

N/A

Extended Format Remote Temperature 1 High Byte

00h

FBh

N/A

Extended Format Remote Temperature 1 Low Byte

00h

FCh

N/A

Extended Format Remote Temperature 2 High Byte

00h

FDh

N/A

Extended Format Remote Temperature 2 Low Byte

00h

02h

N/A

Status register

00h

03h

09h

Configuration register

47h

N/A

0Fh

One Shot Command

--

FEh

N/A

Manufacturer Identifier

5Dh

FFh

N/A

Silicon Revision Identifier

01h

11h, 16h, 4Ah,

60h, 61h, 62h,

79h, 7Ah

11h, 16h, 4Ah,

60h, 61h, 62h,

79h, 7Ah

Reserved Registers for production test

Table 3.5 High Byte Temperature Register

REGISTER

BIT 7

BIT 6BIT 5BIT 4BIT 3BIT 2BIT 1

BIT 0

Temperature High Byte Registers

00h, 01h, F8h, FAh, FCh

SIGN

64

32

16

8421

Table 3.6 Low Byte Temperature Register

REGISTER

BIT 7

BIT 6

BIT 5

BIT 4

BIT 3

BIT 2

BIT 1

BIT 0

Temperature Low Byte Registers 23h,

10h, F9h, FBh, FDh

0.500

0.250

0.125

00000

Table 3.4 Register Table (continued)

REGISTER

READ

ADDRESS

REGISTER

WRITE

ADDRESS

REGISTER NAME

DEFAULT

VALUE