LM64EVAL National Semiconductor, LM64EVAL Datasheet - Page 22

• Manufacturer Part Number: LM64EVAL
• Description: BOARD EVALUATION LM64
• Manufacturer: National Semiconductor

Specifications of LM64EVAL

• Sensor Type: Temperature, Fan Controller
• Sensing Range: 0°C ~ 85°C
• Interface: SMBus (2-Wire/I²C)
• Sensitivity: ±1°C
• Voltage - Supply: 3 V ~ 3.6 V
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: LM64
• Lead Free Status / RoHS Status: Not applicable / Not applicable

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ADDRESS
ADDRESS
00
05 (0B)
2.0 LM64 Registers
07 (0D)
08 (0E)
Local Temperature And Local High Setpoint Registers
Remote Diode Temperature, Offset And Setpoint Registers
Hex
HEX
Hex
00
05
BF
01
10
11
12
13
14
19
21
LOCAL TEMPERATURE REGISTER (8-bits)
HEX
Read/
Write
Read
Only
R/W
LOCAL HIGH SETPOINT REGISTER (8-bits)
Read/
Write
Read
Read
Only
Only
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Bits
7:0
7:0
Bits
7:0
7:5
4:0
7:5
7:5
4:0
7:0
7:5
4:0
7:0
7:5
4:0
7:0
7:0
7:3
2:1
0
Value
POR
0x46
(70˚)
N/A
(70˚C)
(85˚C)
(10˚C)
Value
00000
(0˚C)
0x0A
POR
0x46
0x55
N/A
N/A
00
00
00
00
00
00
00
00
00
00
0
Local Temperature Reading (8-bit)
(Continued)
OFFSET (MSB)
Reading (MSB)
OFFSET (LSB)
Setpoint (MSB)
Setpoint (MSB)
Reading (LSB)
Remote Diode
Setpoint (LSB)
Setpoint (LSB)
Remote Diode
Remote HIGH
Remote HIGH
Remote Diode
Remote Diode
Remote Diode
Remote LOW
Remote LOW
T_CRIT Limit
Temperature
Temperature
Temperature
Temperature
Temperature
Comparator
Hysteresis
Local HIGH Setpoint
Remote
Remote
T_CRIT
Name
Mode
Filter
Name
This is the MSB of the LM64 remote diode temperature value, 2’s
complement. Bit 7 is the sign bit, bit 6 has a weight 64˚C, and bit 0 has
a weight of 1˚C. Read this byte first. The actual remote diode
temperature is 16˚C higher than the values in registers 0x01 and 0x10.
This is the LSB of the LM64 remote diode temperature value, in 2’s
complement. Bit 7 has a weight 0.5˚C, bit 6 has a weight of 0.25˚C, and
bit 5 has a weight of 0.125˚C. The actual remote diode temperature is
16˚C higher than the values in registers 0x01 and 0x10.
Always 00.
These registers contain the offset value added to, or subtracted from, the
remote diode’s reading to compensate for the different non-ideality
factors of different processors, diodes, etc. The 2’s complement value, in
these registers is added to the output of the LM64’s ADC to form the
temperature reading contained in registers 01 and 10.
Always 00.
High setpoint temperature for remote diode. Same format as Remote
Temperature Reading (registers 01 and 10).
Always 00.
Low setpoint temperature for remote diode. Same format as Remote
Temperature Reading (registers 01 and 10).
Always 00.
This 8-bit integer storing the T_CRIT limit is initially 85˚C (101˚C actual
remote T_Crit limit). This value can be changed at any time after
power-up.
8-bit integer storing T_CRIT hysteresis. T_CRIT stays activated until the
remote diode temperature goes below [(T_CRIT Limit) — (T_CRIT
Hysteresis)].
These bits are unused and should always set to 0.
00: Filter Disabled
01: Filter Level 1 (minimal filtering, same as 10)
10: Filter Level 1 (minimal filtering, same as 01)
11: Filter Level 2 (maximum filtering)
0: the ALERT pin functions as an Interrupt or ARA mode.
1: the ALERT pin behaves as a comparator, asserting itself when an
ALERT condition exists, de-asserting itself when the ALERT condition
goes away.
22
8-bit temperature of the LM64.
High Setpoint for the internal diode.
Description
Description