Texas Instruments MSP50C6xx - Manual (Page 361)

Initializing the MSP50C6xx
6-7 Applications
orb a0,0x7c ;set PLLM for CPU clock of 8 MHz
mov *save_clkspdctrl,a0 ;save the ClkSpdCtrl value for later, when
;waking up from mid or deep sleep
mov a0~,TIM2REFOSC + TIM2IMR ;disable TIMER 2
out IntGenCtrl,a0~
mov a0~,6553
;setup a 200 ms period
out TIM2,a0~ ;load TIM2 and PRD2 in one fell swoop
mov a0~,TIM2ENABLE + TIM2REFOSC + TIM2IMR
out IntGenCtrl,a0~
;use 32 kHz crystal as source, wake up from TIM2
out ClkSpdCtrl,a0 ;set clock to full speed!
idle ;go to sleep...
nop ;wake up 200 ms later, clock running at full speed
nop
nop
;****************************************************************
; Upon reset all ports are set to input and port G output is set
; low (0x0000). Therefore it remains only to enable the pullups
; on port F.
;****************************************************************
in a0,IntGenCtrl
or a0,PFPULLUPS ;enable port F pullups
and a0,~TIM2IMR ;turn off TIMER 2 interrupt
and a0,~TIM2ENABLE ;turn off TIMER 2 ––– added 28.11.99
out IntGenCtrl,a0
;****************************************************************
; Set the DAC to 10 bits, C3x style. For C5x style set bit 3
; high.
;****************************************************************
movb a0,0x02 ;choose 10 bit DAC, C3x style
orb a0,DACON ;enable DAC
out DACCTRL,a0 ;switch DAC on
;****************************************************************
; Initialization complete. Now tidy up and branch to the main
; user code.
;****************************************************************
zac a0 ;tidy up
zac a0~
jmp _main ;jump to the main program