MC9S12HZ128VAL Datasheet, PDF (306/692 Pages) Freescale Semiconductor, Inc – MC9S12HZ256 Data Sheet, Rev. 2.05

Chapter 10 Stepper Stall Detector (SSDV1)
10.4.3 Operation in Low Power Modes
The SSD block can be configured for lower MCU power consumption in three different ways.
• Stop mode powers down the sigma-delta converter and halts clock to the modulus counter. Exit
from Stop enables the sigma-delta converter and the clock to the modulus counter but due to the
converter recovery time, the integration result should be ignored.
• Wait mode with SSDWAI bit set powers down the sigma-delta converter and halts the clock to the
modulus counter. Exit from Wait enables the sigma-delta converter and clock to the modulus
counter but due to the converter recovery time, the integration result should be ignored.
• Clearing SDCPU bit powers down the sigma-delta converter.
10.4.4 Stall Detection Flow
Figure 10-15 shows a flowchart and software setup for stall detection of a stepper motor. To control a
second stepper motor, the SMS bit must be toggled during the SSD initialization.
MC9S12HZ256 Data Sheet, Rev. 2.05
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Freescale Semiconductor