Add testbench that tests the switches prescaling

programs/assignment2code.prog

@@ -1,64 +1,86 @@
 reset:
-br always >main
-nop
+    br always >main
+    nop
 hardfault:
-reti
-nop
+    reti
+    nop
 memfault:
-reti
-nop
+    reti
+    nop
 
 .align
-addr:
-.word 0x000F0000
-//w_cnt_top:	.word 0x1FC000
-w_cnt_top:	.word 0x1		//for simulation only
+led_addr: .word 0x000F0000
+switches_addr: .word 0x000F0004
+base_prescaler: .word 0x1
 
 main:
-ldr r0,>addr	//LED addr
-addi r6,8		//outer counter top
-clr r7			//wait counter
-ldr r8,>w_cnt_top
+    ldr r0,>led_addr    //LED addr
+    addi r6,8        //outer counter top
+    clr r7            //wait counter
+    ldr r8,>base_prescaler
 
 out_loop:
-clr r1
-st08 r0,r1
-call >wait
-nop
+    clr r1
+    st08 r0,r1
+    call >wait_prescaled
+    nop
 
 fill:
-	lsh r1,r1,1
-	addi r1,1
-	st08 r0,r1
-	call >wait
-	nop
+    lsh r1,r1,1
+    addi r1,1
+    st08 r0,r1
+    call >wait_prescaled
+    nop
 
-	addi r5,1
-	cmp neq r5,r6
-	br true >fill
-	nop
-	clr r5
+    addi r5,1
+    cmp neq r5,r6
+    br true >fill
+    nop
+    clr r5
 
 flush:
-	lsh r1,r1,1
-	st08 r0,r1
-	call >wait
-	nop
+    lsh r1,r1,1
+    st08 r0,r1
+    call >wait_prescaled
+    nop
+
+    addi r5,1
+    cmp neq r5,r6
+    br true >flush
+    nop
+    clr r5
+    br always >out_loop
+    nop
+
+wait_prescaled:
+    // Load value from the switches
+    ldr r11,  >switches_addr
+    ld32 r9, r11
+    addi r9, 1
+
+    clr r11
+    add r11, r13, r11 // save link register
+
+    clr r10
+inc_j:
+    call >wait
+    cmp neq r10,r9
+    br true >inc_j
+    addi r10,1
+
+    clr r13
+    add r13, r13, r11 // restore link register
+
+    ret
+    nop
 
-	addi r5,1
-	cmp neq r5,r6
-	br true >flush
-	nop
-	clr r5
-	br always >out_loop
-	nop
 
 //subroutine to iterate until counter overflow
 wait:
-	clr r7				//inititalize inner counter
-	inc_i:
-	cmp neq r7,r8
-	br true >inc_i		//if i=cnt_top
-	addi r7,1
-	ret					//else
-	nop
+    clr r7                //inititalize inner counter
+inc_i:
+    cmp neq r7,r8
+    br true >inc_i        //if i=cnt_top
+    addi r7,1
+    ret                    //else
+    nop