EMC2302 Standard Microsystems Corp., EMC2302 Datasheet - Page 25

• Manufacturer Part Number: EMC2302
• Description: Rpm-based Pwm Fan Controller
• Manufacturer: Standard Microsystems Corp.

ADDR
20h
Dual RPM-Based PWM Fan Controller
Datasheet
SMSC EMC2302
5.1.1
5.2
ADDR
FDh
4Ah
4Bh
4Ch
4Dh
4Eh
4Fh
FEh
FFh
49h
EF
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Configuration
R
R
R
R
R
REGISTER
During Power-On-Reset (POR), the default values are stored in the registers. A POR is initiated when
power is first applied to the part and the voltage on the VDD supply surpasses the POR level as
specified in the electrical characteristics. Any reads to undefined registers will return 00h. Writes to
undefined registers will not have an effect.
Lock Entries
The Lock Column describes the locking mechanism, if any, used for individual registers. All SWL
registers are Software Locked and therefore made read-only when the LOCK bit is set.
The Configuration Register controls the basic functionality of the EMC2302. The bits are described
below. The Configuration Register is software locked.
Bit 7 - MASK - Blocks the ALERT# pin from being asserted.
Configuration Register
Fan 2 Valid TACH
TACH 2 Reading
TACH 2 Reading
Fan 2 Drive Fail
Fan 2 Drive Fail
Manufacturer ID
Band High Byte
Band Low Byte
TACH 2 Target
TACH 2 Target
Software Lock
REGISTER
Product ID
High Byte
High Byte
Low Byte
Low Byte
Revision
NAME
Count
MASK
B7
Table 5.1 EMC2302 Register Set (continued)
DIS_TO
Stores the number of Tach counts used
Holds the target tachometer setting high
Holds the tachometer reading high byte
Holds the target tachometer setting low
must match the target fan speed at full
to determine how the actual fan speed
Holds the tachometer reading low byte
B6
Table 5.2 Configuration Register
indicates Fan 2 is spinning properly
Holds the tachometer reading that
Stores the unique Product ID
Stores the Manufacturer ID
Locks all SWL registers
Revision Registers
WD_EN
DATASHEET
Lock Register
B5
byte for Fan 2
byte for Fan 2
FUNCTION
scale drive
for Fan 2
for Fan 2
Revision
25
B4
-
B3
-
B2
DEFAULT
-
VALUE
5Dh
F5h
00h
00h
F8h
FFh
FFh
F8h
00h
36h
80h
DR_EXT_
CLK
B1
Revision 1.2 (03-22-10)
LOCK
SWL
SWL
SWL
SWL
No
No
No
No
No
No
No
USE_
EXT_
CLK
B0
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PAGE
DEFAULT
40h