Texas Instruments TMS320F20x/F24x DSP A.6.4 C Functions for Initializing the TMS320F240, A-51

PRELIMINARY

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

OR	#06fh	;	set WDDIS	bit	and WDCHK2:0 bits, WDCLK to max.
SACL	WDCR	;	write ACC	out	to WDTCR

*****************************************************************************

* Step 9. Deallocate the local frame*

*****************************************************************************

SBRK 1+1	; deallocate frame, point to saved FP
***************************************************************************
* Step 10. restore the frame pointer		*

*****************************************************************************

LAR AR0,*± ; pop FP

***************************************************************************

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

* stack*

***************************************************************************

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

A.6.4 C Functions for Initializing the TMS320F240

***********************************************************************
*	TMS320x240 Initialization Function				*
* Arguments passed from Caller: None					*
*	Local Variables:			None	*
***********************************************************************
SYSSR		.set	0701Ah
SYSCR		.set	07018h
WDTCR		.set	07029h	;WD Control reg
CKCR0		.set	0702ah	;PLL Clock Control Register 0
CKCR1		.set	0702ch	;PLL Clock Control Register 1
DP_PF1		.set	224
		.globl _c240init
		.text
		.def	_c240init
_c240init:				; presume ARP = AR1 (SP)**
***************************************************************************
* On entry, presume ARP = AR1 (SP)						*
*						*
* Step 1. pop the return address off the h/w stack and push to s/w stack						*

*****************************************************************************

POPD *+ ; pop return address, push on software stack

;ARP=AR1, SP=SP+1

*****************************************************************************

* Step 2. push the frame pointer onto s/w stack*

*****************************************************************************

SAR AR0,*+ ; push AR0 (FP) onto SP

;ARP=AR1, SP=SP+2

*****************************************************************************

* Step 3. Allocate the local frame*

*****************************************************************************

SAR	AR1,*	; *SP = FP
LAR	AR0,#1	; FP = size of local frame, 1
LAR	AR0,*0+	; FP = SP, SP += size ==> allocate frame

*****************************************************************************

PRELIMINARY Assembly Source Listings and Program Examples A-51