constants for rSTAT register

constants/hardware_constants.asm

@@ -131,6 +131,17 @@ DEF rLCDC_WINDOW_TILEMAP EQU 6     ; 0=9800-9BFF, 1=9C00-9FFF
 DEF rLCDC_ENABLE         EQU 7     ; 0=Off, 1=On
 DEF LCDC_DEFAULT         EQU (1 << rLCDC_ENABLE) | (1 << rLCDC_WINDOW_TILEMAP) | (1 << rLCDC_WINDOW_ENABLE) | (1 << rLCDC_SPRITES_ENABLE) | (1 << rLCDC_BG_PRIORITY)
 DEF rSTAT                EQU $ff41 ; LCDC Status (R/W)
+DEF rSTAT_STATUS_FLAGS   EQU  %00000011 ; LCD controller status (Read Only)
+DEF rSTAT_HBLANK_MASK    EQU  %00000000 ; In H-Blank (Read Only)
+DEF rSTAT_VBLANK_MASK    EQU  %00000001 ; In V-Blank (Read Only)
+DEF rSTAT_OAM_MASK       EQU  %00000010 ; OAM is used by system (Read Only)
+DEF rSTAT_LCD_MASK       EQU  %00000011 ; Both OAM and VRAM used by system (Read Only)
+DEF rSTAT_BUSY           EQU 1     ; When set, VRAM access is unsafe (Read Only)
+DEF rSTAT_LYC            EQU 2     ; LYC=LY (0=Different, 1=Equal) (Read Only)
+DEF rSTAT_INT_HBLANK     EQU 3     ; Mode 00: H-Blank (Selectable)
+DEF rSTAT_INT_VBLANK     EQU 4     ; Mode 01: V-Blank (Selectable)
+DEF rSTAT_INT_OAM        EQU 5     ; Mode 02: OAM (Selectable)
+DEF rSTAT_INT_LYC        EQU 6     ; LYC=LY Coincidence (Selectable)
 DEF rSCY                 EQU $ff42 ; Scroll Y (R/W)
 DEF rSCX                 EQU $ff43 ; Scroll X (R/W)
 DEF rLY                  EQU $ff44 ; LCDC Y-Coordinate (R)

engine/gfx/dma_transfer.asm

@@ -194,7 +194,7 @@ HDMATransfer_NoDI:
 	; while not [rSTAT] & 3: pass
 .loop2
 	ldh a, [rSTAT]
-	and $3
+	and rSTAT_STATUS_FLAGS
 	jr z, .loop2
 	; load the 5th byte of HDMA
 	ld a, b
@@ -253,12 +253,12 @@ _continue_HDMATransfer:
 	; while [rSTAT] & 3: pass
 .rstat_loop_1
 	ldh a, [rSTAT]
-	and $3
+	and rSTAT_STATUS_FLAGS
 	jr nz, .rstat_loop_1
 	; while not [rSTAT] & 3: pass
 .rstat_loop_2
 	ldh a, [rSTAT]
-	and $3
+	and rSTAT_STATUS_FLAGS
 	jr z, .rstat_loop_2
 	; load the 5th byte of HDMA
 	ld a, e

engine/menus/savemenu_copytilemapatonce.asm

@@ -47,7 +47,7 @@ SaveMenu_CopyTilemapAtOnce:
 	ld l, 0
 	ld a, SCREEN_HEIGHT
 	ldh [hTilesPerCycle], a
-	ld b, 1 << 1 ; not in v/hblank
+	ld b, 1 << rSTAT_BUSY ; not in v/hblank
 	ld c, LOW(rSTAT)
 
 .loop

engine/phone/phonering_copytilemapatonce.asm

@@ -51,7 +51,7 @@ PhoneRing_CopyTilemapAtOnce:
 	ld l, 0
 	ld a, SCREEN_HEIGHT
 	ldh [hTilesPerCycle], a
-	ld b, 1 << 1 ; not in v/hblank
+	ld b, 1 << rSTAT_BUSY ; not in v/hblank
 	ld c, LOW(rSTAT)
 
 .loop

home/init.asm

@@ -108,7 +108,7 @@ Init::
 	ldh [hSCY], a
 	ldh [rJOYP], a
 
-	ld a, $8 ; HBlank int enable
+	ld a, 1 << rSTAT_INT_HBLANK
 	ldh [rSTAT], a
 
 	ld a, $90