1°C Triple Temperature Sensor with Resistance Error Correction & Hotter of Two Zones

Datasheet

Revision 1.37 (02-05-07)

18

SMSC EMC1053

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

undefined registers will not have an effect.

The EMC1053 uses an interlock mechanism that will update the Low byte of a particular monitor when

the High Byte is read. This prevents changes in register content when the ADC updates between

successive reads.

4.1

Legacy Temperature Data Registers (00h, 23h, 01h, 10h, F8h,

F9h)

As shown in Table 4.1, each temperature monitor has two data registers. The 11 bit temperature data

is stored aligned to the left resulting in the High Byte containing temperature in 1°C steps and the Low

Byte containing fractions of a degree.

4.2

Extended Format Temperature Registers (FAh-FDh)

The Extended Format Temperature Registers store only the external diode temperatures in the

extended data format. This is because, due to the operating range limitations of the EMC1053, the

internal temperature could not benefit from the extended temperature range. Like the Legacy data

formatting, the data is stored in two registers per temperature channel.

4.3

Status Register - 02h

The Status Register is a read only register and returns the operational status of the part. External diode

faults are indicated by bits 1 and 0. If either bit is set to ‘1’, then a diode fault has occurred. When a

diode fault occurs, the D1 or D2 status bit is set, but otherwise the data remains unchanged.

Bit 7 - Busy - indicates that the ADC is currently converting a temperature.

Bit 4 - HOTTER - during Hotter of Two mode, this bit indicates which of the external diode channels

is hotter. If this bit is ‘0’, then External Diode 1 is hotter or equal to External Diode 2. If this bit is ‘1’,

then External Diode 2 is hotter than External Diode 1. During normal operation, this bit will always read

a ‘0’.

Bit 1 - D2 - indicates that a diode fault has occurred on External Diode 2.

Bit 0 - D1 - indicates that a diode fault has occurred on External Diode 1.

4.4

Configuration Register (03h Read, 09h Write)

Table 4.2 Status Register

ADDR

REGISTER

B7

B6

B5

B4

B3

B2

B1

B0

DEFAULT

02h

Status

Busy

-

-

HOTTER -

-

D2

D1

00h

Table 4.3 Configuration Register

ADDR

REGISTER

B7

B6

B5

B4

B3

B2

B1

B0

DEFAULT

03h Read,

09h Write

Config

-

STANDBY

-

-

-

CR<2:0>

45h