1.5°C SMBus Temperature Sensor in Miniature SOT-23
Datasheet
Note 4.3 Revision number may change. Please obtain the latest version of this document from the
SMSC web site.
At device power-up, the default values are stored in all registers. A power-on-reset is initiated when
power is first applied to the part and the VDD supply exceeds the POR threshold. Reads of undefined
registers will return 00h and writes to undefined registers will be ignored.
The EMC1001 uses an interlock mechanism that locks the low byte value when the high byte register
is read. This prevents updates to the low byte register between high byte and low byte reads. This
interlock mechanism requires that the high byte register always be read prior to reading the low byte
register.
4.7
Status Register
The status register is a read only register that stores the operational status of the part. When either
TLOW or THIGH are set (TA ≤ low limit or TA > high limit) and the ALERT/THERM2 pin is not masked,
the ALERT/THERM2 pin will assert. See Section 4.3 on page 11 for more details on the ALERT
function.
Table 4.4 Status Register
STATUS REGISTER
BIT
NAME
Busy
FUNCTION
7
6
5
4
3
2
1
0
1 when ADC is converting
THIGH
TLOW
1 when Temperature High Limit is exceeded
1 when Temperature Low Limit is exceeded
Reserved
Reserved
Reserved
Reserved
THRM
1 when THERM limit is exceeded
Bit 7 indicates that the ADC is busy converting a value. Bits 6 and 5 indicate that the temperature
measurement is above or below the limits respectively. Bit 0 indicates that the measured temperature
has exceeded the THERM limit. When bit 0 goes high the ADDR/THERM output will be asserted.
Each bit is cleared individually when the status register is read, provided that the error condition for
that bit no longer exists. The ALERT/THERM2 output is latched and will not be reset until the host has
responded with an alert response address (ARA=0001 100). The ALERT/THERM2 output will not reset
if the status register has not been cleared.
4.8
Configuration Register
The configuration register controls the functionality of the temperature measurements.
SMSC EMC1001
Revision 1.6 (01-29-07)
DATA1S3HEET
SMSC [ SMSC CORPORATION ]
