Rainbow Electronics LM95010 - Manual (Page 15)

2.0 Register Set
(Continued)
Bit Type Description
1 R/W Shutdown (Shutdown Mode). When set to "1" this bit stops the operation of all functions and places the
device in the lowest power consumption mode.
0: Device in Active Mode. (default)
1: Device in Shutdown Mode.
2 R/W LowPwr (Low-Power Mode). When set to "1" this bit slows the operation of all functions and places the
device in a low power consumption mode. In Low-Power Mode, the conversion rate of the LM95010 is
effected see Section 2.10 for further details.
0: Device in Active Mode. (default)
1: Device in Low-Power Mode.
3 RO Not supported. Will always read "0".
4 R/W EnF1 (Enable Function 1). When bit is set to "1" this bit Function 1 is enabled for operation. A function may
require setup before this bit is set. The function registers can be accessed even when the function is
disabled.
0: Function 1 is disabled. (default)
1: Function is enabled.
15-5 RO Not supported. Will always read "0".
2.9 TEMPERATURE MEASUREMENT FUNCTION (TYPE - 0001)
This section defines the register structure and operation of a Temperature Measurement function as it applies to the LM95010.
The FuncDescriptor value of this function is ‘0001’.
2.9.1 Operation
The Temperature Measurement function as implemented in the LM95010 supports one temperature zone, the LM95010’s internal
temperature (LM95010’s junction temperature). Since the LM95010 only supports one temperature measurement the Sensor
Scan function as defined in the SensorPath specification only applies to one temperature sensor. A temperature scan is enabled
by the SensorEnable bit (EN0). The minimum scan rate is recommended to be 4Hz (i.e. the measurement data is updated at least
once in 250 ms), see Section 2.10 for further details. In Low-Power Mode, the scan rate is four time lower than the scan rate in
Active Mode. The scan rate effects the bus bandwidth required to read the results. The sampling rate of the temperature
measurements can also be controlled via the Conversion Rate register, see Section 2.10 for further details.
Data Readout When a new result is stored in the Readout register a Function Event is generated. Reading the Readout
register clears the Status Function 1 flag (SF1). The result is available in the Readout register waiting for the master to read it
during the master sensor read sequence. If a new result is ready before the previous result has been read, the new result
overwrites the previous result and the Error Function 1 flag (ERF1) is set (indicating an overrun event). Reading the Readout
register clears also the Error Function 1 flag (ERF1). The Readout register contains the temperature data, and the sensor number.
Since the LM95010 only supports one temperature zone the sensor number field will always report zero. Other fields in the
Readout register as defined by the SensorPath specification are not supported.
Readout Resolution The resolution of the readout is defined in the Temperature Capabilities register. The resolution of the
LM95010 is fixed and cannot be modified by software.
Function Event The Temperature Measurement function generates a Function Event whenever a temperature conversion
cycle is completed and new data is stored in the Readout Register. When the new data is stored into the Readout register the SF1
bit in the device Status register is set to "1" and remains set, until it is cleared by reading the Readout register. An Attention
Request is generated on the bus, only if it is enabled by the Attention Enable bit (ATE) in the Temperature Control register.
Setup Before Enabling No setup is required for the Temperature Measurement function before the function is enabled.
2.9.2 Temperature Capabilities (Addr 10o)
Reg
Add
Register
Name
R/
W
P
O
R
Val
Bit
15
MSb
Bit
14
Bit
13
Bit
12
Bit
11
Bit
10
Bit
9
Bit
8
Bit
7
Bit
6
Bit
5
Bit
4
Bit
3
Bit
2
Bit
1
Bit
0
LSb
001 000
Temperature
Capabilities
R 014Ah
Reserved
Int
Sens
Rout
Size
Sign 10Bits
0.25˚C
Resolution
0 0 0 0 0 0 0 1 0 1 0 0 1 0 1 0
This register defines the format of the temperature data in the readout register. The LM95010 only supports one format as defined
by the values of this register.
LM95010
www.national.com 15