1 files changed, 26 insertions, 0 deletions
diff --git a/software/first/delay.S b/software/first/delay.S
new file mode 100644
index 0000000..cb49ba1
--- /dev/null
+++ b/software/first/delay.S
@@ -0,0 +1,26 @@
+.section .text
+.align 2
+.global delay
+.include "memory_map.inc"
+
+
+# a0 is delay in milliseconds argument
+
+delay:
+	addi sp, sp, -16 # Allocate stack frame
+	sw ra, 12(sp)    # save return address to the stack
+
+	li t0, MTIME     # load the timer register
+	lw t1, 0(t0)     # load value of the timer
+
+	li t2, MTIME_FREQUENCY # get clock freq (approx.)
+	mul t2, t2, a0         # multiply milliseconds with freq
+  add t2, t1, t2         # target mtime is now in t2
+
+1:
+  lw t1, 0(t0)      # load value of the timer
+	blt t1, t2, 1b    # keep looping until target mtime has been reached
+
+  lw ra, 12(sp)   # load return address
+  addi sp, sp, 16 # deallocate stack frame
+	ret