.syntax unified
.global main

.type main, %function
main:
  bl init
  mov r3, 0
  mov r4, 0
  b restart

@Restart label to playback the song after it's stop
restart:

  mov r0,0
  add r4,1

  @Loading the location of the array for notes and use it's element in a register
  ldr r6, =array
  ldr r7, [r6, 4]
  mov r5, r7
  ldr r8, [r6]
  mov r9, 1

  @Loading the location of the array for each notes duration and use it's element in a register
  ldr r10, =duration
  ldr r11, [r10, 4]

  @increase the tempo of the song by substing duration of each notes
  sub r11, r11, r3

  @Revert the tempo back to normal after 3 playback of continuously increasing tempo
  cmp r4,4
  itte eq
  moveq r3, 0
  moveq r4, 0
  addne r3, 2000



  b positive_peak


positive_peak:

  @Set the positive peak for volume at 0x7fff
  mov r0, 0x7fff

  @Change notes or pitch when the notes has finished it's duration
  sub r11, 1
  cmp r11, 0
  beq change_pitch


  sub r7, 1
  cmp r7, 0
  beq negative_peak

  @Using push and pull to store value in stack because it's reset to 0 when AUDIO is played
  push {r3}
  bl BSP_AUDIO_OUT_Play_Sample
  pop {r3}

b positive_peak

negative_peak:


  mov r0, 0x8000
  sub r11, 1
  cmp r11, 0
  beq change_pitch
  add r7, 1
  cmp r7, r5
  beq positive_peak
  push {r3}
  bl BSP_AUDIO_OUT_Play_Sample
  pop {r3}

 b negative_peak


@Label to change to the next notes after finishing the current note's duration
change_pitch:
  add r9, 1
  cmp r8, r9


  beq restart
  mov r12, 4
  mul r12, r9, r12

  @Load the next notes and duration to the register
  ldr r7, [r6,r12]
  mov r5, r7
  ldr r11, [r10, r12]
  sub r11, r11, r3
  b positive_peak

.data
array:
  @Array Size
  .word 122
  @Array of notes in the song
  .word 132, 0, 111, 176, 0, 111, 0, 132, 166, 166, 166, 0, 0, 0, 0, 176, 166, 132, 111, 88, 0, 111, 0, 132, 74, 79, 83, 0, 0, 0, 0, 118, 0, 88, 132, 0, 88, 118, 0, 88, 0, 125, 132, 0, 148, 0, 148, 148, 148, 0, 0, 0, 148, 148, 148, 0, 0, 0, 157, 157, 166, 166, 176, 0, 111, 88, 0, 111, 0, 132, 148, 148, 148, 0, 0, 74, 74, 74, 0, 0, 0, 132, 111, 88, 0, 111, 0, 132, 88, 99, 0, 0, 0, 0, 99, 124, 166, 176, 99, 124, 176, 111, 132, 186, 198, 140, 166, 198, 148, 148, 148, 0, 0, 0, 0, 0, 105, 99, 88, 83, 66, 56



duration:
  @Array of duration for each notes
  .word 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 48000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 48000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 26000, 14000, 14000, 14000, 14000, 14000, 14000, 26000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000, 14000