EMC2302 Standard Microsystems Corp., EMC2302 Datasheet - Page 33

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

ADDR
36h
46h
ADDR
Dual RPM-Based PWM Fan Controller
Datasheet
35h
45h
SMSC EMC2302
5.11
5.12
R/W
R/W
R/W
R/W
R/W
R/W
GAIND OR GAINP OR GAINI [1:0]
The Gain registers store the gain terms used by the proportional and integral portions of each of the
RPM-based Fan Speed Control Algorithms. These gain terms are used as the KD, KI, and KP gain
terms in a classic PID control solution.
Bits 5 - 4 - GAINDX[1:0] - Controls the derivative gain term used by the FSC algorithm as shown in
Table
Bits 3-2 - GAINIX[1:0] - Controls the integral gain term used by the FSC algorithm as shown in
Table
Bits 1-0 - GAINP[1:0] - Controls the proportional gain term used by the FSC algorithm as shown in
Table
1
0
0
1
1
The Fan Spin Up Configuration registers control the settings of Spin Up Routine. The Fan Spin Up
Configuration registers are software locked.
Bit 7 - 6 - DRIVE_FAIL_CNTx[1:0] - Determines how many update cycles are used for the Drive Fail
detection function as shown in
the desired tach target.
Gain Registers
Fan Spin Up Configuration Registers
Fan 1 Spin Up
Fan 2 Spin up
Configuration
Configuration
REGISTER
5.18.
5.18.
5.18.
REGISTER
Register
Register
Gain 1
Gain 2
Table 5.19 Fan Spin Up Configuration Registers
DRIVE_FAIL_
DRIVE_FAIL_
B7
CNT1 [1:0]
CNT2 [1:0]
B7
-
-
0
0
1
0
1
Table 5.17 Gain Registers
B6
Table 5.18 Gain Decode
Table
B6
DATASHEET
-
-
5.20. This circuitry determines whether the fan can be driven to
NOKICK1
NOKICK2
B5
GAIND1[1:0]
GAIND2[1:0]
33
B5
B4
B4
SPIN_LVL1[2:0]
SPIN_LVL2[2:0]
RESPECTIVE GAIN FACTOR
B3
GAINI1[1:0]
GAINI2[1:0]
B3
4x (default)
B2
B2
1x
2x
8x
GAINP1[1:0]
GAINP2[1:0]
B1
SPINUP_TIME
SPINUP_TIME
B1
Revision 1.2 (03-22-10)
1 [1:0]
2 [1:0]
B0
B0
DEFAULT
2Ah
2Ah
DEFAULT
19h
19h