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Add BIT instructions to the 6809

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Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon 2018-08-19 16:30:31 +01:00
parent d17cd1777a
commit a5a8b6059d
1 changed files with 11 additions and 0 deletions
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11
MC6809/src/mc6809.cpp
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@ -87,6 +87,17 @@ int EightBit::mc6809::execute(uint8_t cell) {
case 0x67: addCycles(6); BUS().write(asr(AM_indexed_byte())); break; // ASR (ASR, indexed)
case 0x77: addCycles(7); BUS().write(asr(AM_extended_byte())); break; // ASR (ASR, extended)
// BIT
case 0x85: addCycles(2); andr(A(), AM_immediate_byte()); break; // BIT (BITA, immediate)
case 0x95: addCycles(4); andr(A(), AM_direct_byte()); break; // BIT (BITA, direct)
case 0xA5: addCycles(4); andr(A(), AM_indexed_byte()); break; // BIT (BITA, indexed)
case 0xB5: addCycles(5); andr(A(), AM_extended_byte()); break; // BIT (BITA, extended)
case 0xc5: addCycles(2); andr(B(), AM_immediate_byte()); break; // BIT (BITB, immediate)
case 0xd5: addCycles(4); andr(B(), AM_direct_byte()); break; // BIT (BITB, direct)
case 0xe5: addCycles(4); andr(B(), AM_indexed_byte()); break; // BIT (BITB, indexed)
case 0xf5: addCycles(5); andr(B(), AM_extended_byte()); break; // BIT (BITB, extended)
// NEG
case 0x00: addCycles(6); BUS().write(neg(AM_direct_byte())); break; // NEG (direct)
case 0x40: addCycles(2); A() = neg(A()); break; // NEG (NEGA, inherent)