Motorola M68HC08 manual State Diagram, Software Flowchart Interrupts

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

INTERRUPT

PWM RELOAD

BEMF ZERO CROSSING

SENSING ISR:

SENSE ZERO CROSSING INPUT:

–TAKE 3 ZC INPUT SAMPLES

–BEMF STATE = S1&S2 S2&S3

0

BEMF state

1
YES	NO
V_TASC = ris. edge	V_TASC = fal. edge
NO	YES
SET ZERO CROSSING GET:
– SET ICR_F - ZERO CROS. GET
– T_ZCROS = TIMER2 TIME
RTI

Software Design

State Diagram

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

RTI

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

RTI

Figure 5-6. Software Flowchart — Interrupts

5.5 State Diagram

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.

DRM028 — Rev 0		Designer Reference Manual
MOTOROLA	Software Design	89
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