lm96163cisdx-1 National Semiconductor Corporation, lm96163cisdx-1 Datasheet - Page 11

• Manufacturer Part Number: lm96163cisdx-1
• Description: Remote Diode Digital Temperature Sensor With Integrated Fan Control And Trutherm Bjt Transistor Beta Compensation Technology
• Manufacturer: National Semiconductor Corporation

4.
5.
6.
7.
8.
The ARA, 000 1100, is a general call address. No device
should ever be assigned to this address.
The ALERT Configuration bit in the Remote Diode Tempera-
ture Filter and Comparator Mode Register must be set low in
order for the LM96163 to respond to the ARA command.
The ALERT output can be disabled by setting the ALERT
Mask bit in the Configuration Register. The power-on default
is to have the ALERT Mask bit and the ALERT Configuration
bit low.
1.2.4 TCRIT Function
The TCRIT output will be activated whenever the RCRIT bit
in the ALERT Status register is set. This occurs whenever the
remote temperature exceeds the value set by the Remote
T_CRIT Setpoint register. There is a hysteresis associated
with the T_CRIT Setpoint that is set by the value in the Re-
mote T_CRIT Hysteresis register. The RCRIT bit will be reset
when the remote temperature equals or is less than the value
defined by Remote T_CRIT Setpoint minus T_CRIT Hystere-
sis. The resolution of the comparison is 1 °C. For example if
T_CRIT = 110 °C and THYST = 5 °C the TCRIT output will
activate when the temperature reading is 111 °C and deacti-
vate when the temperature reading is 105 °C.
When the LM96163 powers up the T_CRIT limit is locked to
the default value. It may be changed after the T_CRIT Limit
Override bit (TCRITOV) bit, found in the Configuration Reg-
ister, is set.
The format of the Remote T_CRIT setpoint register is con-
trolled by the USF bit found in the Enhanced configuration
register. The temperature reading format used for the T_CRIT
comparisons is +255 °C to -256°C.
Alerting Device(s) send their address. While transmitting
their address, alerting devices sense whether their
address has been transmitted correctly. (The LM96163
will reset its ALERT output and set the ALERT Mask bit
once its complete address has been transmitted
successfully.)
Master/slave NoACK
Master sends STOP
Master attends to conditions that caused the ALERT to
be triggered. The ALERT Status Register is read and fan
started, setpoints adjusted, etc.
Master resets the ALERT Mask bit in the Configuration
Register.
FIGURE 3. ALERT Output as an SMBus ALERT
Temperature Response Diagram
30041009
11
1.3 SMBus INTERFACE
Since the LM96163 operates as a slave on the SMBus the
SMBCLK line is an input and the SMBDAT line is bidirectional.
The LM96163 never drives the SMBCLK line and it does not
support clock stretching. According to SMBus specifications,
the LM96163 has a 7-bit slave address. All bits, A6 through
A0, are internally programmed and cannot be changed by
software or hardware.
The complete slave address is:
1.4 POWER-ON RESET (POR) DEFAULT STATES
For information on the POR default states see Section 2.2
LM96163 Register Map in Functional Order.
1.5 TEMPERATURE DATA FORMAT
Temperature data can only be read from the Local and Re-
mote Temperature value registers. The data format for all
temperature values is left justified 16-bit word available in two
8-bit registers. Unused bits will always report "0". All temper-
ature data is clamped and will not roll over when a tempera-
ture exceeds full-scale value.
Remote temperature and remote high setpoint temperature
data can be represented by an 11-bit, two's complement word
or unsigned binary word with an LSb (Least Significant Bit)
equal to 0.125°C.
When the digital filter is enabled on the remote channel, tem-
perature data is represented by a 13-bit unsigned binary or
12-bit plus sign (two's complement) word with an LSb equal
to 0.03125°C.
Temperature
Temperature
A6
+255.875°C
1
+0.125°C
−0.125°C
+0.125°C
+125°C
+255°C
+201°C
+125°C
+25°C
−25°C
−55°C
+25°C
+1°C
−1°C
+1°C
0°C
0°C
11-bit, 2's complement (10-bit plus sign)
A5
0
11-bit, unsigned binary
A4
0
0111 1101 0000 0000
0001 1001 0000 0000
0000 0001 0000 0000
0000 0000 0010 0000
0000 0000 0000 0000
1111 1111 1110 0000
1111 1111 0000 0000
1110 0111 0000 0000
1100 1001 0000 0000
1111 1111 1110 0000
1111 1111 0000 0000
1100 1001 0000 0000
0111 1101 0000 0000
0001 1001 0000 0000
0000 0001 0000 0000
0000 0000 0010 0000
0000 0000 0000 0000
Binary
Binary
A3
1
Digital Data
Digital Data
A2
1
A1
0
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7D00h
FFE0h
C900h
FFE0h
C900h
7D00h
1900h
0100h
0020h
0000h
FF00h
E700h
FF00h
1900h
0100h
0020h
0000h
Hex
Hex
A0
0