assemb.s

ADuC7020/26是ADI模拟公司开发的ARM7TDMI内核

/*********************************************************************

 Author        : ADI - Apps            www.analog.com/MicroConverter

 Date          : Sept. 2005

 File          : assemb.s

 Hardware      : Applicable to ADuC702x rev H or I silicon
                 Currently targetting ADuC7026.

 Description   : Blink_Setup enables P4.2 as an output.
 				 Blink takes the value passed too it by the C code, 
				 which is passed in R0 as per APCS Spec., and 
				 compliments P4.2. 
				 assemb is compiled in ARM by default.

				 If desired, you may return a value in R0 to the C file.

Note:			 For more complex examples you will be required to
				 save any registers you corrupt onto the stack. 
				 		
*********************************************************************/

AREA ?C?bla, CODE, READONLY, ALIGN=2

PUBLIC Blink_Setup?A
PUBLIC Blink_Setup?T

Blink_Setup?T    PROC CODE16
		BX		R15 					; switch to ARM mode
		NOP      
        ENDP

Blink_Setup?A    PROC CODE32

		GP4DAT 	EQU		0XFFFFF460

		;Begin by initialising Port 4.2 as an output

		LDR		R0,=GP4DAT
		MOV		R1,#0x04000000
		STR		R1,[R0]

		BX		LR 					; return      
        ENDP

			
PUBLIC Blink?A
PUBLIC Blink?T

Blink?T    PROC CODE16
		BX		R15 					; switch to ARM mode
		NOP      
        ENDP
		  
Blink?A		PROC CODE32

LOOP:
		SUBS    r0,r0,#1		 	; Decrement Delay Value, Set Flags
    	bne     LOOP				; If zero, continue

		LDR		R0,=GP4DAT
		LDR		R1, [R0]
 		EOR		R1,R1,#0x00040000		;Toggle Pin value
		STR		R1,[R0]

		bx		lr 					; return

        ENDP

        END