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Share instruction fetch and halt implementations

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This commit is contained in:
Adrian Conlon
2025-05-04 11:41:28 +01:00
parent 2336222c97
commit 93e09c192f
6 changed files with 28 additions and 30 deletions
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8
M6502/Core.cs
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@@ -516,7 +516,7 @@ namespace M6502
if (this.RDY.Raised())
{
this.FetchInstruction();
this.OpCode = this.FetchInstruction();
if (this.RESET.Lowered())
{
this.HandleRESET();
@@ -536,17 +536,19 @@ namespace M6502
}
}
private void FetchInstruction()
protected override byte FetchInstruction()
{
this.LowerSYNC();
System.Diagnostics.Debug.Assert(this.Cycles == 1, "An extra cycle has occurred");
// Can't use "FetchByte", since that would add an extra tick.
this.ImmediateAddress();
this.OpCode = this.ReadFromBus();
var returned = this.ReadFromBus();
System.Diagnostics.Debug.Assert(this.Cycles == 1, "BUS read has introduced stray cycles");
this.RaiseSYNC();
return returned;
}
#endregion