From 83c920e893fabbb807580f8ad799e3473d613768 Mon Sep 17 00:00:00 2001 From: Martin Hellspong Date: Thu, 21 Apr 2016 15:00:46 +0200 Subject: [PATCH] Fix unimplemented instruction cycles According to the M68000UM, the two unimplemented instruction exceptions both cost 34 cycles, not 4. Actually, that's a bit of a lie. Table 8-14. Exception Processing Execution Times does not even mention unimplemented instruction exceptions, but section 6.3.6 Illegal and Unimplemented Instructions basically says that unimplemented instructions are just a special case of illegal instructions in that they have separate exception vectors. --- m68kcpu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/m68kcpu.c b/m68kcpu.c index 800800d..45e20aa 100755 --- a/m68kcpu.c +++ b/m68kcpu.c @@ -129,8 +129,8 @@ uint8 m68ki_exception_cycle_table[3][256] = 34, /* 7: TRAPV */ 34, /* 8: Privilege Violation */ 34, /* 9: Trace */ - 4, /* 10: 1010 */ - 4, /* 11: 1111 */ + 34, /* 10: 1010 */ + 34, /* 11: 1111 */ 4, /* 12: RESERVED */ 4, /* 13: Coprocessor Protocol Violation (unemulated) */ 4, /* 14: Format Error */