Diff: binasm.s

Revision:

0:13e4e935bed6

Child:

2:a81c9bc37084

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/binasm.s	Thu Jan 27 06:24:28 2011 +0000
@@ -0,0 +1,50 @@
+ AREA    |.text|, CODE, READONLY
+ EXPORT  binasm
+
+binasm PROC
+    PUSH {R4, LR}
+    
+    MOV R1, #0
+    MOV R2, #0
+    MOV R3, #0
+
+    ; Load GPIO Port 1 base address in register R1 
+    LDR     R1, =0x2009C020 ; 0x2009C020 = GPIO port 1 base address
+    LDR     R4, =leds
+
+    ;CLEAR LEDS
+    MOV.W   R2, #0xB40000
+    STR   R2, [R1,#0x1C]
+    
+    ADD R3, R3, #12 ; COUNTER FOR LOOP
+    ADD R0, R0, #1  ; INCREMENT PARAMETER BY 1
+    
+loop
+    ; CLEAR THE CARRY FLAG
+    ADC R0, R0, #0
+
+    LDR.W   R2, [R4, R3]
+    LSRS R0, R0, #1  
+
+    STRCC   R2, [R1,#0x1C]  ; if==0, clear LED bit
+    STRCS   R2, [R1,#0x18]  ; if==1, set LED bit    
+
+    CMP R3, #0
+    SUB R3, R3, #4
+    BNE loop
+    
+    POP {R4, PC}
+    ENDP
+
+ AREA |.data|, DATA, READWRITE
+ EXPORT leds
+         
+;BIT MASK FOR LED1...LED4
+
+leds DCD 0x040000 
+     DCD 0x100000
+     DCD 0x200000
+     DCD 0x800000
+    
+    ALIGN
+    END
\ No newline at end of file