State Diagram - Motorola M68HC08 Reference Manual

INTERRUPT
PWM RELOAD
BEMF ZERO CROSSING
SENSING ISR:
SENSE ZERO CROSSING INPUT:
– TAKE 3 ZC INPUT SAMPLES
– BEMF STATE = S1&S2 | S2&S3
BEMF state
V_TASC = ris. edge
NO
SET ZERO CROSSING GET:
– SET ICR_F - ZERO CROS. GET
– T_ZCROS = TIMER2 TIME

5.5 State Diagram

DRM028 — Rev 0
MOTOROLA
Freescale Semiconductor, Inc.
0
1
YES
V_TASC = fal. edge
YES
RTI
Figure 5-6. Software Flowchart — Interrupts
The motor control application can be in one of the eight states shown in
Figure 5-7. Each of these states is described in the subsections
following the figure.
Software Design
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INTERRUPT
TIMER 1 (TIM A CH1)
CURRENT MEASUREMENT ISR:
– START ADC DC-BUS CURRENT CHANNEL
– SERVE VIRTUAL TIMER3
– CURR = VALUE FROM ADC
– IF CURR > CURR_MAX_FAULT:
SET OVC_F (OVERCUR.) FLAG
– SET NEXT ADC CHANNEL NXT_CHNL
NO
INTERRUPT
TIMER 2 (TIM A CH3)
COMMUTATION ISR:
– IF CMTE_F (COMMUTATION ENABLED):
DO MOTOR COMMUTATION STEP
TIMER 1 CURRENT SENSING TO
PWM SYNCHRONIZATION
SET PC_F (PHASE COMMUTATED)
T_CMT = TIMER 2 ACTUAL TIME
– ZERO CROSSING SELECTION
Designer Reference Manual
Software Design
State Diagram
RTI
RTI
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