W83L771W Datasheet, PDF (8/25 Pages) Winbond – H/W Monitoring IC

W83L771W/G
7. FUNCTIONAL DESCRIPTION
7.1 General Description
The W83L771W/G provides one remote temperature sensor input which could be connected to
remote thermistors, 2N3904 transistors, or CPU/GPU thermal diode, and one local on die thermal
sensor to detect ambient temperature. The measured temperature is digitally compared with the value
stored in the programmable High/Low limit Registers and T_CRIT registers. Any out-of-limit value
could be detected by monitoring Status Register (SR). W83L771W/G also supports SMBus^TM 2.0
ALARM protocol and TIMEOUT.
The data format of remote temperature is 10 bit plus sign combined with two 8 bits wide SMBus^TM
access interface. The real temperature equals the measured temperature plus or minus offset value.
Offset value could be set in offset registers. The date format of the offset registers is also the same as
the data format of remote temperature.
7.2 Access Interface
W83L771W/G provides SMBus serial interface to read/write internal registers, and the SMBus address
for read and write is 10011001b and 10011000b, respectively.
The first serial bus access timing is shown as follows:
(a) Serial bus write to internal address register followed by the data byte
0
SCL
780
78
SDA
10 10 0 1 1 00 10 R/W
D7 D6 D5 D4 D3 D2 D1 D0
Start By
Master
Frame 1
Serial Bus Address Byte
AAcckk
b^by^y
Frame 2
7⁷7⁸1⁵W^R
Internal Index Register Byte
A_Ac_ck_k
7₇8₇^bb5₁^yyR_W
0
SCL(Continued)
78
SDA (Continued)
D7 D6 D5 D4 D3 D2 D1 D0
Frame 3
Data Byte
AAck
bb_byy_y
7₇78₇84₁5R_WR
Stop
by
Master
Publication Release Date: March 06
-4-
Revision 0.7