W83782D Datasheet, PDF (13/73 Pages) Winbond – MONITORING IC

Preliminary W83782D
6. FUNCTIONAL DESCRIPTION
6.1 General Description
The W83782D provides 7 analog positive inputs, 3 fan speed monitors, at most 4 sets for fan PWM
(Pulse Width Modulation) control, 3 thermal inputs from remote thermistors or 2N3904 transistors or
Pentium^TM II (Deschutes) thermal diode outputs, case open detection and beep function output when
the monitor value exceed the set limit value including voltage, temperature, or fan counter. When
start the monitor function on the chip, the watch dog machine monitor every function and store the
value to registers. If the monitor value exceeds the limit value, the interrupt status will be set to 1.
6.2 Access Interface
The W83782D provides two interface for microprocessor to read/write internal registers.
6.2.1 ISA interface
The first interface uses ISA Bus to access which the ports of low byte (bit2~bit0) are defined in the
port 5h and 6h. The high byte (from ISA address bus bit15~bit3) of these ports is decoded by Chip
Select (CS#), the general decoded address is set to port 295h and port 296h. These two ports are
described as following:
Port 295h: W83782D Index register port.
Port 296h: Data port.
The register structure is showed as the Figure 1.
Publication Release Date: April 1999
-7-
Revision A1