Miroirs/crab
1
0
Fork 0
mirror of https://github.com/mattrberry/crab.git synced 2025-01-29 20:35:13 +01:00
Code Issues Projects Releases Packages Wiki Activity

add dispstat + reads/writes

Browse source
This commit is contained in:
Matthew Berry 2020-10-09 00:58:07 -07:00
parent 705113eae2
commit cf156829e5
1 changed files with 18 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
src/crab/ppu.cr
View file

@ -25,10 +25,22 @@ class PPU
num bg_mode, 3 # (0-5=Video Mode 0-5, 6-7=Prohibited)
end
class DISPSTAT < BitField(UInt16)
num vcount_setting, 8
num not_used, 2
bool vcounter_irq_enable
bool hblank_irq_enable
bool vblank_irq_enable
bool vcounter # todo update bitfield macro to make values read-only when writing to value
bool hblank # todo update bitfield macro to make values read-only when writing to value
bool vblank # todo update bitfield macro to make values read-only when writing to value
end
getter pram = Bytes.new 0x400
getter vram = Bytes.new 0x18000
getter dispcnt : DISPCNT = DISPCNT.new 0
getter dispstat : DISPSTAT = DISPSTAT.new 0
@cycles = 0
@ -45,8 +57,10 @@ class PPU
def read_io(io_addr : Int) : Byte
case io_addr
when 0x000 then (@dispcnt.value >> 8).to_u8
when 0x001 then @dispcnt.value.to_u8!
when 0x000 then 0xFF_u8 & @dispcnt.value >> 8
when 0x001 then 0xFF_u8 & @dispcnt.value
when 0x004 then 0xFF_u8 & @dispstat.value >> 8
when 0x005 then 0xFF_u8 & @dispstat.value
else raise "Unimplemented PPU read ~ addr:#{hex_str io_addr.to_u8}"
end
end
@ -57,6 +71,8 @@ class PPU
when 0x001 then @dispcnt.value = (@dispcnt.value & 0xFF00) | value
when 0x002 # undocumented - green swap
when 0x003 # undocumented - green swap
when 0x004 then @dispstat.value = (@dispstat.value & 0x00FF) | value.to_u16 << 8
when 0x005 then @dispstat.value = (@dispstat.value & 0xFF00) | value
else raise "Unimplemented PPU write ~ addr:#{hex_str io_addr.to_u8}, val:#{value}"
end
end