SCH3112I-NE SMSC [SMSC Corporation], SCH3112I-NE Datasheet - Page 247

• Manufacturer Part Number: SCH3112I-NE
• Description: LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
• Manufacturer: SMSC [SMSC Corporation]

LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
Datasheet
SMSC SCH311X
24.2.4
(Note
Register
Address
INPUT
25h
26h
27h
Vccp
Vbat
5.0V
VCC
2.5V
VTR
12V
24.10)
Read/
Write
register will read C0h, except for the Vbat input. Vbat is nominally a 3.0V input that is implemented
on a +3.3V (nominal) analog input. Therefore, the nominal reading for Vbat is AEh.
Note: Vbat will only be monitored when the Vbat Monitoring Enable bit is set to ‘1’. Updating the
Note 24.10 Vbat is a nominal 3.0V input source that has been implemented on a 3.3V analog voltage
The Voltage Reading registers will be updated automatically by the device with a minimum frequency
of 4Hz if the average bits located in the Special Function register at offset 7Ch are set to 001. These
registers are read only – a write to these registers has no effect.
Registers 25-27h: Temperature Reading
The Temperature Reading registers reflect the current temperatures of the internal and remote diodes.
Remote Diode 1 Temp Reading register reports the temperature measured by the Remote1- and
Remote1+ pins, Remote Diode 2 Temp Reading register reports the temperature measured by the
Remote2- and Remote2+ pins, and the Internal Diode Temp Reading register reports the temperature
measured by the internal (ambient) temperature sensor. Current temperatures are represented as 12
bit, 2’s complement, signed numbers in Celsius. The 8MSbs are accessible in the temperature reading
registers.
extended precision bits for these readings are accessible in the A/D Converter LSBs Register (85h-
86h). The Temperature Reading register will return a value of 80h if the remote diode pins are not
implemented by the board designer or are not functioning properly (this corresponds to the diode fault
interrupt status bits). The Temperature Reading registers will be updated automatically by the
SCH311X Chip with a minimum frequency of 4Hz.
Note: These registers are read only – a write to these registers has no effect.
Each of the temperature reading registers are mapped to a zone. Each PWM may be programmed to
operate in the auto fan control operating mode by associating a PWM with one or more zones. The
following is a list of the zone associations.
R
R
R
NOMINAL
VOLTAGE
12.0V
3.3V
3.0V
5.0V
1.5V
3.3V
2.5V
Vbat register automatically clears the Vbat Monitoring Enable bit.
Remote Diode 1 (Zone 1) Temp
Remote Diode 2 (Zone 3) Temp
Internal Diode (Zone 2) Temp
Table 24.3
monitoring input.
Register Name
READING AT
REGISTER
VOLTAGE
NOMINAL
Reading
Reading
Reading
C0h
AEh
C0h
C0h
C0h
C0h
C0h
shows the conversion for the 8-bit reading value shown in these registers. The
Table 24.2 Voltage vs. Register Reading
MAXIMUM
VOLTAGE
DATASHEET
16.00V
4.38V
4.38V
6.64V
2.00V
4.38V
6.64V
(MSb)
Bit 7
7
7
7
231
Bit 6
6
6
6
READING AT
REGISTER
MAXIMUM
VOLTAGE
Bit 5
FFh
FFh
FFh
FFh
FFh
FFh
FFh
5
5
5
Bit 4
4
4
4
Bit 3
VOLTAGE
MINIMUM
3
3
3
0V
0V
0V
0V
0V
0V
0V
Bit 2
2
2
2
MINIMUM VOLTAGE
Bit 1
1
1
1
READING AT
REGISTER
Rev 0.2 (09-28-04)
(LSb)
Bit 0
00h
00h
00h
00h
00h
00h
00h
0
0
0
Default
Value
N/A
N/A
N/A