W83783S Datasheet, PDF (11/57 Pages) Winbond – MONITORING IC

W83783S
Preliminary
6. FUNCTIONAL DESCRIPTION
6.1 General Description
The W83783S provides at most 6 analog positive inputs, 3 fan speed monitors, 2 sets for fan PWM
(Pulse Width Modulation) control, 2 thermal inputs from remote thermistors or 2N3904 transistors or
Pentium^TM II (Deschutes) thermal diode outputs 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 W83783S provides I²C Serial Bus to read/write internal reigsters. In the W83783S there are two
serial bus address. The first address defined at CR[48h] can read/write all registers excluding Bank 1
temperature sensor registers and the address default value is 0101101. The second address defined
at CR[4Ah] bit2-0 only read/write temperature sensor 1 registers and the address default value is
1001001.
6.2.1 The first serial bus access timing are shown as follow:
(a) Serial bus write to internal address register followed by the data byte
0
SCL
780
78
SDA
0
Start By
Master
10110
Frame 1
Serial Bus Address Byte
SCL (Continued)
1 R/W
D7 D6 D5 D4 D3 D2 D1 D0
Ack
Ack
by
Frame 2
by
781D
781D
Internal Index Register Byte
0
78
SDA (Continued)
D7 D6 D5 D4 D3 D2 D1 D0
Frame 3
Data Byte
Ack
by
781D
Stop
by
Master
Figure 1. Serial Bus Write to Internal Address Register followed by the Data Byte
Publication Release Date: April 1999
-6-
Revision 0.55