Manuals / Brands / Computer Equipment / Computer Hardware / SMSC / Computer Equipment / Computer Hardware

SMSC EMC2102 USER MANUAL, 5.6.1General Setup, 5.6.2Fan Spin and Stall Interrupts

1 38

Download 38 pages, 4.31 Mb

Fan Speed Control with the EMC2102 Device

5.6Experiment 6 - Limits and Alerts

This experiment is designed to gain familiarity with the control registers for generating fan related alarms and alerts associated with the EMC2102.

The CMF file for this experiment is EMC2102_default.cmf.

5.6.1General Setup

For all these tests, the Fan Drive Setting register (51h), the TACH Target register (57h) and the TACH Reading registers (58h) are selected to plot. As bits are switched in each of the tests, the register name and address will be provided.

5.6.2Fan Spin and Stall Interrupts

The Configuration/Status page in the ChipMan application contains all the Interrupt configuration and status registers for the fan. In this experiment, the Fan Stall and Fan Spin status bits will be checked. In order to see the status bits change, the Interrupt Status 2 register (23h) is plotted along with other registers listed above. The Interrupt Mask register (24h) should be set to 10h (default) for this set of experiments.

Start the plotting function within ChipMan, and force the fan to stop spinning. This will induce a Fan Stall condition. The plot of the Status Register will show a peak of 1 count for the stall condition, followed by peaks of 2 counts for each time the spin-up routine is invoked, as shown in Figure 5.22, "Fan Spin and Stall". In order to see the spikes mentioned above, the max scale on the register 27h plot needs to be modified. To do this, simply double click the 255 at the top of the "Y" axis, type a different maximum value (10) and enter. And then double click the 0 at the bottom of the "Y" axis, type a minimum value and enter. The scale will be changed.

Revision 0.2 (09-17-07)

USER MANUAL

SMSC EMC2102

26

Contents

USER MANUAL Page Page Page Page Page Figure 4.1 EMC2102 Fan Control Evaluation System Figure 4.2 EVB-EMC2102Board 5.1.1ChipMan Installation 5.1.2Setting Up the ChipMan Figure 5.1 ChipMan Message for First Operation Note: Figure 5.2 ChipMan Device Selection Window Figure 5.3 Selecting the Device and Master Controller Type Figure 5.4 ChipMan Operation Window Notes: Figure 5.5 Changing Fan Speed 5.1.3Plotting From ChipMan Figure 5.6 Plotting from the ChipMan Figure 5.7 Plot Windows Figure 5.8 Plot Examples 5.2.1Getting Started 5.2.2Basic RPM Based Fan Control Figure 5.9 Plots for Proper Control Settings 5.2.3Effects of Loading Figure 5.10 Effects of Loading 5.2.4Register Change Summary Table 5.1 Register Change Summary for Experiment REGISTER DEFAULT 5.3.1Fan Control Parameters Figure 5.11 Fan Control Parameters 5.3.2Getting Started 5.3.3Forced Kick Function Figure 5.12 Forced Kick Function 5.3.4Spin-UpLevel Figure 5.13 60% Spin Level Setting 5.3.5Spin-UpTime Figure 5.14 Reduced Spin-upTime 5.3.6Register Change Summary Table 5.2 Register Change Summary for Experiment 5.4.1General Setup 5.4.2Controlling the Ramp Rate Figure 5.15 Default Ramp Rate Figure 5.16 Default Step Size with Different UPDATE Settings Figure 5.17 Default UPDATE with Different Step Size Settings Figure 5.18 Exceptionally Slow Rate 5.4.3Register Change Summary Table 5.3 Register Change Summary for Experiment 5.5.1General Setup 5.5.2Fan Configuration Register (52h) Figure 5.19 Update Time Modifications 5.5.3FAN Minimum Drive Register (55h) and Valid TACH Count (56h) Figure 5.20 Minimum Drive Setting Figure 5.21 Valid Tach Count Setting 5.5.4Register Change Summary Table 5.4 Register Change Summary for Experiment 5.6.1General Setup 5.6.2Fan Spin and Stall Interrupts Figure 5.22 Fan Spin and Stall 5.6.3Register Change Summary 5.7.1.1Case 1 - Spin-upLvel RPM < Valid RPM < Target RPM Figure 5.24 Theoretical Plot of Case Figure 5.25 Spin-upCase 1 Fix 5.7.1.2Case 2 - Valid RPM << Target RPM < Spin-upLevel RPM 5.7.1.3Case 3 - Valid RPM =< Target RPM << Spin-upLevel RPM Figure 5.30 Spin-upCase Figure 5.31 Spin-upRoutine Restarted During Normal Operation 5.7.1.4Case 4 - 4.Valid RPM < Spin-upLevel RPM (rpm60 or rpm75) < Target RPM 5.7.1.5Case 5 - Correct RPM Relationships with a Slow Response DC Fan Figure 6.1 A Typical 2-poleDC Fan Figure 6.2 Output Signal of a 2-poleFan Figure 6.3 Fan TACH Measurement With EMC2102 [1] 6.2.1General Setup 6.2.2Set the Correct LIMIT2K Value 6.2.3Determine the Number of Poles and the Maximum Fan Speed 6.2.4Determine the Minimum Startup Speed 6.2.5Determine the Stall Speed 6.2.6Determine the Minimum Valid TACH Speed 6.2.8.1Spin-upLEVEL (Register 53h[2]) 6.2.8.2Minimum Fan Speed 6.2.8.3Valid TACH Count Speed (Function of Register 56h) 6.2.8.4Maximum Fan Speed