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control write pending impl

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kirjavascript 2021-04-28 00:12:54 +01:00
parent 4708e7666a
commit 7db75526e6
1 changed files with 33 additions and 6 deletions
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39
emu/src/vdp.rs
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@ -41,6 +41,10 @@ impl VDP {
}
}
fn dma_length(&self) -> u32 {
self.registers[19] as u32 | ((self.registers[20] as u32) << 8)
}
pub fn read(&self, mut address: u32) -> u32 {
address &= 0x1F;
@ -78,7 +82,7 @@ impl VDP {
}
}
pub fn write_data_port(&mut self, value: u32) {
fn write_data_port(&mut self, value: u32) {
if self.control_code & 1 == 1 {
self.write_data(VDPType::from(self.control_code & 0xE), value);
}
@ -87,8 +91,7 @@ impl VDP {
if self.dma_pending {
self.dma_pending = false;
let length = self.registers[19] as u32 | ((self.registers[20] as u32) << 8);
for _ in 0..length {
for _ in 0..self.dma_length() {
self.VRAM[self.control_address as usize] = (value >> 8) as _;
self.control_address += self.registers[15] as u32;
self.control_address &= 0xFFFF;
@ -96,18 +99,42 @@ impl VDP {
}
}
pub fn write_control_port(&mut self, value: u32) {
fn write_control_port(&mut self, value: u32) {
if self.control_pending {
self.control_code = (self.control_code & 3) | ((value >> 2) & 0x3c);
self.control_address = (self.control_address & 0x3fff) | ((value & 3) << 14);
self.control_pending = false;
if self.control_code & 0x20 > 0 && self.registers[1] & 0x10 > 0 {
if (self.registers[23] >> 6) == 2 && (self.control_code & 7) == 1 {
self.dma_pending = true;
} else if (self.registers[23] >> 6) == 3 {
todo!("DMA copy");
} else {
let source =
(self.registers[21] << 1)
| (self.registers[22] << 9)
| (self.registers[23] << 17);
for _ in 0..self.dma_length() {
// let word = mem.read_word(source)
source += 2;
self.write_data(VDPType::from(self.control_code & 0x7), word);
self.control_address += self.registers[15] as _;
self.control_address &= 0xffff;
}
}
}
} else {
if value & 0xc000 == 0x8000 {
let (register, value) = ((value >> 8) & 0x1F, value & 0xFF);
// set VDP register
if self.registers[1] & 4 > 0 || register <= 10 {
self.registers[register as usize] = value as u8;
}
self.control_code = 0;
} else {
self.control_code = (self.control_code & 0x3c) | ((value >> 14) & 3);
self.control_address = (self.control_address & 0xc000) | (value & 0x3fff);
self.control_pending = true;