Blinky program with timer interrupts

programs/timer_blinky.prog

@@ -0,0 +1,97 @@
+reset:
+    br always >main
+    nop
+
+hardfault:
+    reti
+    nop
+
+memfault:
+    reti
+    nop
+
+timer_interrupt:
+    br >timer_interrupt_handler
+    nop
+
+.align
+led_addr: .word 0x000F0000
+timer_counter_addr: .word 0x000F0008
+timer_status_addr: .word 0x000F000C
+dmem_start_addr: .word 0x00000400
+dmem_end_addr: .word 0x000004FC
+priority_mask: .word 0xFFFFFF03
+xor_mask: .word 0xFFFFFFFF
+
+main:
+    // Initialize stack pointer to the end of the data memory
+    ldr r12, >dmem_end_addr
+
+    // Set runtime priority
+    ldr r0, >priority_mask
+    and r14, r0, r14
+
+    ldr r0,>led_addr                // LED addr
+    ldr r1,>timer_status_addr      // Timer addr
+
+    // Init
+    clr r9 // 0 if we are currently filling, 1 if we are currently flushing
+    clr r8 // shift register
+    clr r5 // shift counter
+    clr r4 // shift counter top constant
+    addi r4, 10
+
+    // Enable the timer...
+    clr r2
+    addi r2, 0x3 // enable and repeat bit set
+    st32 r1, r2
+
+loop:
+    br >loop
+    nop
+
+timer_interrupt_handler:
+     clr r10
+     addi r10, 1
+     cmp eq r9, r10
+     br true >flush
+     nop
+     br always >fill
+     nop
+
+rst_fill:
+     clr r5
+fill:
+     clr r9
+
+     // When shift register full, jump to flush
+     addi r5, 1
+     cmp eq r5, r4
+     br true >rst_flush
+     nop
+
+     lsh r8, r8, 1
+     addi r8, 1
+     st08 r0, r8
+
+     reti
+     nop
+
+rst_flush:
+     clr r5
+flush:
+     clr r9
+     addi r9, 1
+
+     // When shift register empty, jump to fill
+     addi r5, 1
+     cmp eq r5, r4
+     br true >rst_fill
+     nop
+
+     lsh r8, r8, 1
+     st08 r0, r8
+
+     reti
+     nop
+

programs/timer_test.prog

@@ -19,7 +19,7 @@ led_addr: .word 0x000F0000
 timer_counter_addr: .word 0x000F0008
 timer_status_addr: .word 0x000F000C
 dmem_start_addr: .word 0x00000400
-dmem_end_addr: .word 0x000004FF
+dmem_end_addr: .word 0x000004FC
 priority_mask: .word 0xFFFFFF03
 
 main:
@@ -44,7 +44,7 @@ main:
     st08 r1, r2
 
 loop:
-    call >loop
+    br >loop
     nop