6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2024-11-23 03:32:32 +00:00
Code Issues Projects Releases Wiki Activity

Fixes register-relative JMP and JSR.

Browse Source
This commit is contained in:
Thomas Harte 2019-06-03 15:29:50 -04:00
parent 1328708a70
commit 4d4ddded6d
3 changed files with 14 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
Processors/68000/Implementation/68000Implementation.hpp
View File

@ -756,9 +756,14 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
overflow_flag_ = sub_overflow() & 0x80000000;
} break;
// JMP: copies the source to the program counter.
// JMP: copies EA(0) to the program counter.
case Operation::JMP:
program_counter_.full = active_program_->source->full;
program_counter_ = effective_address_[0];
break;
// JMP: copies the source bus data to the program counter.
case Operation::RTS:
program_counter_ = source_bus_data_[0];
break;
/*

10
Processors/68000/Implementation/68000Storage.cpp
View File

@ -615,7 +615,7 @@ struct ProcessorStorageConstructor {
{0xffc0, 0x4ec0, Operation::JMP, Decoder::JMP}, // 4-108 (p212)
{0xffc0, 0x4e80, Operation::JMP, Decoder::JSR}, // 4-109 (p213)
{0xffff, 0x4e75, Operation::JMP, Decoder::RTS}, // 4-169 (p273)
{0xffff, 0x4e75, Operation::RTS, Decoder::RTS}, // 4-169 (p273)
{0xf0c0, 0x9000, Operation::SUBb, Decoder::ADD_SUB}, // 4-174 (p278)
{0xf0c0, 0x9040, Operation::SUBw, Decoder::ADD_SUB}, // 4-174 (p278)
@ -2326,8 +2326,7 @@ struct ProcessorStorageConstructor {
switch(mode) {
default: continue;
case Ind: // JSR (An)
// There'll be no computed address, just grab the destination directly from an address register.
storage_.instructions[instruction].source = &storage_.address_[ea_register];
op(int(Action::CopyToEffectiveAddress) | MicroOp::SourceMask);
op(Action::PrepareJSR);
op(Action::PerformOperation, seq("np nW+ nw np", { ea(1), ea(1) }));
break;
@ -2352,18 +2351,17 @@ struct ProcessorStorageConstructor {
} break;
case Decoder::RTS: {
storage_.instructions[instruction].source = &storage_.source_bus_data_[0];
op(Action::PrepareRTS, seq("nU nu"));
op(Action::PerformOperation, seq("np np"));
} break;
case Decoder::JMP: {
storage_.instructions[instruction].source = &storage_.effective_address_[0];
storage_.instructions[instruction].set_source(storage_, ea_mode, ea_register);
const int mode = combined_mode(ea_mode, ea_register);
switch(mode) {
default: continue;
case Ind: // JMP (An)
storage_.instructions[instruction].source = &storage_.address_[ea_register];
op(int(Action::CopyToEffectiveAddress) | MicroOp::SourceMask);
op(Action::PerformOperation, seq("np np"));
break;

2
Processors/68000/Implementation/68000Storage.hpp
View File

@ -106,7 +106,7 @@ class ProcessorStorage {
CMPb, CMPw, CMPl,
TSTb, TSTw, TSTl,
JMP,
JMP, RTS,
BRA, Bcc,
DBcc,
Scc,