Texas Instruments MSP50C614 manual Begloop

MSP50C614/MSP50P614 Initialization Codes

out	IntGenCtrl,a0	;clear all interrupt mask bits, disable
timers
mov	r0,0x000	;point to beginning of RAM
mov	r4,RAM_SIZE ± 2	;do a loop RAM_SIZE times
BEGLOOP
rtag	*r0	;reset tag
mov	*r0++,a0	;clear the RAM
ENDLOOP
mov	STR,0	;clear string register
mov	ap0,0	;clear accum pointer 0
mov	ap1,0	;clear accum pointer 1
mov	ap2,0	;clear accum pointer 2
mov	ap3,0	;clear accum pointer 3
mov	r0,0	;clear register 0
mov	r1,0	;clear register 1
mov	r2,0	;clear register 2
mov	r3,0	;clear register 3
mov	r4,0	;clear register 4
mov	r5,0	;clear register 5
mov	r6,0	;clear register 6
mov	r7,0	;clear register 7
mov	sv,0	;clear shift value register
mov	TOS,*0x000	;clear top of stack register
mov	PH,*0x000	;clear product high register
mov	MR,*0x000	;clear multiplier register

;****************************************************************

;Choose the source for the reference oscillator. Set the PLLM

;register accordingly (in this case for a CPU clock of 8 MHz)

;and then set TIMER 2 to a 200 ms period.

;Go to sleep (do an IDLE) and wake up when the clock has

;reached full speed and is stable. ;**************************************************************** #if CRO_FLAG

mov	a0,CROENABLE	;enable crystal oscillator
#else
#if C614_FLAG
in	a0,RTRIM	;for C614 read trim value from register
#else
mov	a0,RESISTORTRIM	;for P614 the user supplies the trim value
#endif
and	a0,0x3f	;only want lower 6 bits
mov	a0~,a0	;save a copy for later
mov	sv,10	;need to shift left by 10
shltpl	a0,a0	;bit 1 is now bit 11, bit 0 now bit 10
or	a0,RTOENABLE	;enable resistor±trimmed oscillator
and	a0,~IDLEBIT	;clear bit 10
; 6 bit trim resides in bits 15±11 and bit 9 (LSB of trim value)
and	a0~,a0~,0x01	;look at bit 0 of trim value
jz	trimbit0	;do nothing if it is zero
or	a0,0x0200	;else set bit 9
trimbit0
#endif
orb	a0,PLLMBITS	;set PLLM for CPU clock of 8 MHz

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