Freescale Semiconductor DRM079 manual Kbies, Kbipe, #MTIMBUSCLKMTIMDIV256, Mtimclk, #255, Mtimmod

Implementation
sta	KBIES	;HALL rising Edge Trigger
sta	KBIPE	;KBI Enable

;-------------------------------------------------------
;Config MTIM
;
;Timer prescalar=256 -> Timer clk = 16kHz
;Bus = 4MHz
;Max OF period = 16.384ms
;Timer resolution = 64us
;-------------------------------------------------------	mov	#(MTIM_BUS_CLKMTIM_DIV_256), MTIMCLK
	mov	#255, MTIMMOD
;-------------------------------------------------------
;Motor Start Sequence
;-------------------------------------------------------
ResetPosition:		#mPWM1, PTAD	; Lock FAN in reset position
	mov
Dly1	lda	#30	;
	bsr	Delay	; for Delay 0.5s
	dbnza	Dly1	;
	clr	PTAD	; de-energize coils
	bsr	Delay
; Drive L2		#mPWM2	; Select L2 Coils
	ldx
	bsr	SetPWM	; Drive coil
	bsr	Delay	; De-energize coils
	inc	MotorRunning	; otherwise Update Software flag
;-------------------------------------------------------
;Fan Control Loop
;-------------------------------------------------------
FanControlLoop:
;1) Drive L1 coil			; HALL falling edge trigger
	clr	KBIES
	ldx	#mPWM1	; Select L1 Coil
	bsr	SetPWM	; Drive coil
;2) Read Temp Sensor			; Read Sensor value
	jsr	ReadSensor
;3) Dead time control			; Wait dead time period
	StartTimer
	wait	#(mMTIMSC_TSTPmMTIMSC_TRST), MTIMSC; mask interrupt and clear flag
	mov
;4) Drive L2 coil			; HALL rising edge trigger
	bset	HALL, KBIES
	ldx	#mPWM2	; Select L2 Coil
	bsr	SetPWM	; Drive coil
		Variable Speed DC Fan Control using the MC9RS08KA2, Rev. 0
28			Freescale Semiconductor