64 lines
1.2 KiB
C#
64 lines
1.2 KiB
C#
using System;
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using System.Collections.Generic;
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using System.Linq;
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using System.Text;
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using System.Threading.Tasks;
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namespace Essgee.Emulation.CPU
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{
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public class SM83CGB : SM83
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{
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// TODO: better way of implementing this?
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public bool IsDoubleSpeed { get; private set; }
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public SM83CGB(MemoryReadDelegate memoryRead, MemoryWriteDelegate memoryWrite) : base(memoryRead, memoryWrite) { }
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protected override void EnterHaltState()
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{
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if (ime)
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{
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halt = true;
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pc--;
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}
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else
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{
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if ((memoryReadDelegate(0xFF0F) & memoryReadDelegate(0xFFFF) & 0x1F) != 0)
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currentCycles += 8;
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else
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halt = true;
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}
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}
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protected override void Stop()
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{
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pc++;
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// Perform speed switch; get IO register value
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var key1 = memoryReadDelegate(0xFF4D);
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// Is speed switch pending?
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if ((key1 & 0b1) != 0)
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{
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// Clear pending flag
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key1 &= 0xFE;
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if (((key1 >> 7) & 0b1) != 0)
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{
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// Was double speed, now normal speed
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key1 &= 0x7F;
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IsDoubleSpeed = false;
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}
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else
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{
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// Was normal speed, now double speed
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key1 |= 0x80;
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IsDoubleSpeed = true;
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}
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// Write register value
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memoryWriteDelegate(0xFF4D, key1);
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}
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}
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}
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}
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