Prog 2 modified to swap between LEDs

lab2/lab2.hex

@@ -1,6 +1,6 @@
 :10C0000031400004B240805A2001F240F700220083
-:10C01000F24060002100F24061002100F240C200C5
+:10C01000F24060002100F24061002100F240420045
-:10C020002100F240C3002100F24014002100F24040
+:10C020002100F24043002100F24014002100F240C0
 :10C0300015002100F24046002100F2404700210097
 :04C0400032D01000EA
 :02FFFE0000C041

lab2/lab2_notes.txt

@@ -9,3 +9,11 @@ Note to self:
       program will not run without exiting
     - max value of a word is 2^16 = 65536, so halving blink rate by double dec count of 40000
       means adding another decrementation of 40000 in another register
+
+off -> red -> green -> both -> off
+00 -> 01 -> 10 -> 11 -> 00
+0x00 -> 0x01 -> 0x40 -> 0x41 -> 0x00
+0000 0000 -> 0000 0001 -> 0100 0000 -> 0100 0001 -> 0000 0000
+        xor 0x01      xor 0x41    xor 0x01     xor 0x41
+                xor 0x40      xor 0x40      xor 0x40
+

lab2/prog2.asm

@@ -4,22 +4,24 @@
 RESET:
 	mov.w   #0x400,         SP
 	mov.w   #WDTPW|WDTHOLD, &WDTCTL
-	mov.b   #11110111b,     &P1DIR
+	mov.b   #11110111b,     &P1DIR		; all pins outputs except P1.3
-	mov.b   #01001001b,     &P1OUT
+	mov.b   #01001001b,     &P1OUT		; LED1, LED2 on, P1.3 HI (?)
-	mov.b   #00001000b,     &P1REN
+	mov.b   #00001000b,     &P1REN		; enable resistor for P1.3
-	mov.b   #00001000b,     &P1IE
+	mov.b   #00001000b,     &P1IE		; P1.3 set as an interrupt
-	mov.w   #0x0049,        R7
+	mov.w   #0x0049,        R7			; R7 = 0000 0000 0100 1001
-	mov.b   R7,             &P1OUT
+	mov.b   R7,             &P1OUT		; LED1, LED2 on, P1.3 HI (?)
-	EINT
+	mov.b	#0x0041,		R8			; value to xor with R7
+	EINT								; enable interrupts
 	bis.w   #CPUOFF,        SR
 PUSH:
-	xor.w #0000000001000001b, R7
+	xor.w	R8, 			R7			
-	mov.b R7,               &P1OUT
+	xor.w   #0x0040, 		R8			; 0x0041 -> 0x0001 -> 0x0041
-	bic.b #00001000b,       &P1IFG
+	mov.b 	R7,             &P1OUT		; set LEDs to new state
-	reti
+	bic.b 	#00001000b,     &P1IFG		; interrupt flag P1.3 set to 0
+	reti								; return from interrupt
 
 	org 0xffe4
-	dw PUSH
+	dw PUSH								; interrupt from button goes here
 
 	org 0xfffe
-	dw RESET
+	dw RESET							; interrupt from reset button goes here

lab2/prog2.hex

@@ -1,7 +1,7 @@
 :10C0000031400004B240805A2001F240F700220083
 :10C01000F24049002100F2422700F2422500374059
-:10C020004900C247210032D232D0100037E041002F
+:10C020004900C24721007840410032D232D010008E
-:0AC03000C2472100F2C223000013F2
+:10C0300007E838E04000C2472100F2C223000013A5
-:02FFE4002CC02F
+:02FFE40030C02B
 :02FFFE0000C041
 :00000001FF