Texas Instruments TMS320F20x/F24x DSP manual Preliminary, A-52

Using the Algorithms With C Code to Erase and Reprogram the 'F240

PRELIMINARY

* Step 5. begin code that will initialize the '240 registers*

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CLRC	SXM	;	Clear	Sign Extension Mode
CLRC	OVM	;	Reset	Overflow Mode

*Set Data Page pointer to page 1 of the peripheral frame

LDP #DP_PF1 ; Page DP_PF1 includes WET through EINT frames

*Clear system status register reset bits (PORRST, ILLADR, SWRST, & WDRST)

LACL	#020h	;	load mask	pattern to clear rst flags
SACL	SYSSR	;	write ACC	to SYSSR

*Set Watchdog timer period to 1 second

LACL	#02Fh	;	set WDCHK2 & 0 bits, WDCLK divider to max (1s)
SACL	WDTCR	;	write ACC out to WDTCR

*Configure PLL for 4±MHz xtal, 10±MHz SYSCLK, and 20±MHz CPUCLK

*	SPLK	#00E4h,CKCR1	;CLKIN(XTAL)=4 MHz,CPUCLK=20 MHz
*	SPLK	#00C3h,CKCR0	;CLKMD=PLL Enable,SYSCLK=CPUCLK/2

*Configure PLL for 10±MHz osc, 10±MHz SYSCLK, and 20±MHz CPUCLK SPLK #00B1h,CKCR1 ;CLKIN(OSC)=10 MHz,CPUCLK=20 MHz

SPLK #00C3h,CKCR0 ;CLKMD=PLL Enable,SYSCLK=CPUCLK/2

*Set VCCAON bit and CLKSRC1:0; leave other bits at their reset values. SPLK #40C8h,SYSCR ; SYSCR <= 40C8h

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* Step 9. Deallocate the local frame*

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SBRK 1+1 ; deallocate frame, point to saved FP

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* Step 10. restore the frame pointer*

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LAR AR0,*± ; pop FP

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* Step 11. copy the return address from the s/w stack and push onto h/w *

* stack*

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PSHD *	; push return address on h/w stack
RET	; return
.en

A-52 PRELIMINARY