W83637HF Datasheet, PDF (29/149 Pages) Winbond – LPC I/O

W83637HF
6. HARDWARE MONITOR
6.1 General Description
The W83637HF can be used to monitor several critical hardware parameters of the system, including
power supply voltages, fan speeds, and temperatures, which are very important for a high-end
computer system to work stable and properly. W83637HF provides LPC interface to access hardware.
An 8-bit analog-to-digital converter (ADC) was built inside W83637HF. The W83637HF can
simultaneously monitor 5 analog voltage inputs(addition monitor 3.3V & 5V VDD power), 3 fan
tachometer inputs, 3 remote temperature, one case-open detection signal. The remote temperature
sensing can be performed by thermistors, or 2N3904 NPN-type transistors, or directly from Intel^TM
Deschutes CPU thermal diode output. Also the W83637HF provides: 3 PWM (pulse width modulation)
outputs for the fan speed control; beep tone output for warning; SMI#(through serial IRQ or OVT pin),
OVT# signals for system protection events.
Through the application software or BIOS, the users can read all the monitored parameters of system
from time to time. And a pop-up warning can be also activated when the monitored item was out of the
proper/preset range. The application software could be Winbond's Hardware Doctor^TM, or Intel^TM LDCM
(LanDesk Client Management), or other management application software. Also the users can set up
the upper and lower limits (alarm thresholds) of these monitored parameters and to activate one
programmable and maskable interrupts. An optional beep tone could be used as warning signal when
the monitored parameters is out of the preset range.
6.2 Access Interface
The W83637HF provides two interface for microprocessor to read/write hardware monitor internal
registers.
6.2.1 LPC interface
The first interface uses LPC Bus to access which the ports of low byte (bit2~bit0) are defined in the
port 5h and 6h. The other higher bits of these ports is set by W83637HF itself. The general decoded
address is set to port 295h and port 296h. These two ports are described as following:
Port 295h: Index port.
Port 296h: Data port.
The register structure is showed as the Figure 6.1
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Publication Release Date: June 25, 2003
Revision 1.3