ASC7512 ETC2 [List of Unclassifed Manufacturers], ASC7512 Datasheet - Page 13

• Manufacturer Part Number: ASC7512
• Description: DIGITAL TEMPERATURE SENSOR WITH INTEGRATED FAN CONTROL
• Manufacturer: ETC2 [List of Unclassifed Manufacturers]

Temperature Measurement
Temperatures are measured with a precision Delta-V
sigma-delta converter. The user may set limits on these readings to be continuously monitored and alarm bits set when they
are exceeded. Separately, the measurements are also delivered to the automatic fan control system to adjust fan speed. The
following registers contain the readings from the internal and remote sensors.
Registers 25-10h and 26-15h: Zone Temperature Reading (10-Bit, 2’s Complement Reporting)
The Zone Temperature registers reflect the current temperature of the internal and remote diodes. Processor (Zone 1)
Temp register reports the temperature measured by the thermal diode connected to the Remote - and Remote + pins.
Internal (Zone 2) Temp register reports the temperature measured by the internal (junction) temperature sensor.
Temperatures are represented as 10 bit, 2’s complement, signed numbers, in Celsius, as shown below in Table 1.
The Temperature Reading register will return a value of 8000h if the remote diode pins are not used by the board designer or
are not functioning properly. This reading will cause the zone limit bit (bit 4) in the Interrupt Status Register (41h) and the
remote diode fault status bit (bit 6) in the Interrupt Status Register 2 (42h) to be set. These registers are read-only – a write
to these registers has no effect.
Temperature Measurement Configuration and ALERT Limits
Registers 09h, 0Ah, 0Fh, 22h: Conversion Rate and ALERT Configuration
© Andigilog, Inc. 2006
Register
Address
Register
Address
0Ah
25h
10h
26h
15h
09h
Table 1 Relationship between Temperature and 2’s Complement Digital Output, -55°C to +125°C
Read/
Read/
Write
Write
R/W
R/W
R
R
R
R
Zone 1
Temperature
Zone 1
Temperature (LS
Byte)
Zone 2
Temperature
Zone 2
Temperature (LS
Byte)
Register Name
Configuration
Conversion Rate
Register Name
Temperature
+1.75°C
+0.25°C
-1.75°C
+125°C
+100°C
+50°C
+25°C
+10°C
-55°C
(MSB)
CONV7
0°C
(MSB)
Mask
Bit 7
Alert
Bit 7
9
1
9
1
CONV6
Bit 6
Run/
Stop
Bit 6
BE
8
0
8
0
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Digital Output (2’s Complement)
0111
0110
0011
0001
0000
0000
0000
0000
1111
1100
methodology converted to a digital temperature reading by a 10-bit
10-Bit Resolution
High Byte
CONV5
Alert/
Bit 5
Tach
- 13 -
Bit 5
X
X
7
7
1101
0100
0010
1001
1010
0001
0000
0000
1110
1001
CONV4
Bit 4
RES
Bit 4
X
X
6
6
00
00
00
00
00
11
01
00
01
00
Low Byte
CONV3
XX
XX
XX
XX
XX
XX
XX
XX
XX
XX
Bit 3
RES
Bit 3
Ignore
X
X
5
5
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
CONV2
Bit 2
RES
Bit 2
X
X
4
4
CONV1
Bit 1
RES
Bit 1
August 2006 - 70A05003
3
X
3
X
aSC7512
CONV0
(LSB)
(LSB)
Bit 0
Bit 0
RES
X
X
2
2
Default
Default
Value
Value
00
00
00
00
00
08