掌機 - Game Boy Color - Assembly - VBLANK

參考資訊：
https://bgb.bircd.org/
https://github.com/gbdev/rgbds
https://github.com/sinamas/gambatte
https://github.com/lancekindle/DMGreport

暫存器



main.s

SCX        equ $ff43
IE         equ $ffff
IEF_VBLANK equ %00000001
LCDC       equ $ff40
LCDCF_ON   equ %10000000

section "vblank", rom0[$0040]
    reti

section "lcdc", rom0[$0048]
    reti

section "timer", rom0[$0050]
    reti

section "serial", rom0[$0058]
    reti

section "joypad", rom0[$0060]
    reti

section "entry", rom0[$0100]
    nop
    jp _start

section "header", rom0[$0104]
    db $ce, $ed, $66, $66, $cc, $0d, $00, $0b, $03, $73, $00, $83, $00, $0c, $00, $0d
    db $00, $08, $11, $1f, $88, $89, $00, $0e, $dc, $cc, $6e, $e6, $dd, $dd, $d9, $99
    db $bb, $bb, $67, $63, $6e, $0e, $ec, $cc, $dd, $dc, $99, $9f, $bb, $b9, $33, $3e
    db "0123456789abcde"
    db $80
    db 0, 0
    db 0
    db 0
    db 0
    db 0
    db 1
    db $33
    db 0
    db 0
    dw 0

_start:
    di
    ld sp, $ffff
    ld a, IEF_VBLANK
    ld [IE], a
    ei

    ld d, 32
    ld bc, tile
    ld hl, $8000
copy_tile:
    ld a, [bc]
    ld [hl+], a
    inc bc
    dec d
    jr nz, copy_tile

    ld b, 0
    ld hl, color
copy_palette:
    ld a, b
    ld [$ff68], a
    ld a, [hl]
    ld [$ff69], a
    inc hl
    inc b
    ld a, b
    cp 8
    jr nz, copy_palette

    ld a, 1
    ld [$9800], a

loop:
    halt

    ld a, [SCX]
    inc a
    ld [SCX], a
    jp loop

color:
    dw $7fff
    dw $001f
    dw $03e0
    dw $7c00

tile:
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000
    db %00000000

    db %11111111
    db %00000000
    db %11111111
    db %00000000
    db %11111111
    db %00000000
    db %11111111
    db %00000000
    db %11111111
    db %00000000
    db %11111111
    db %00000000
    db %11111111
    db %00000000
    db %11111111
    db %00000000

執行halt指令後，CPU進入省電模式，待VBLANK中斷發生後，才繼續往下執行，每發一次VBLANK中斷，移動x捲軸一次

完成