folkert/KEK
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

MMR1 locking

Browse source
This commit is contained in:
folkert van heusden 2024-04-12 22:43:35 +02:00
parent 616674f8b1
commit 773d2f4e94
Signed by untrusted user who does not match committer: folkert
GPG key ID: 6B6455EDFEED3BD1
2 changed files with 9 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
bus.h
View file

@ -170,6 +170,7 @@ public:
uint16_t getMMR2() { return MMR2; } uint16_t getMMR2() { return MMR2; }
uint16_t getMMR3() { return MMR3; } uint16_t getMMR3() { return MMR3; }
uint16_t getMMR(int nr) { uint16_t *mmrs[] { &MMR0, &MMR1, &MMR2, &MMR3 }; return *mmrs[nr]; } uint16_t getMMR(int nr) { uint16_t *mmrs[] { &MMR0, &MMR1, &MMR2, &MMR3 }; return *mmrs[nr]; }
bool isMMR1Locked() { return !!(getMMR0() & 0160000); }
void clearMMR1(); void clearMMR1();
void addToMMR1(const int8_t delta, const uint8_t reg); void addToMMR1(const int8_t delta, const uint8_t reg);
void setMMR0(const uint16_t value); void setMMR0(const uint16_t value);

14
cpu.cpp
View file

@ -365,7 +365,7 @@ void cpu::queue_interrupt(const uint8_t level, const uint8_t vector)
void cpu::addToMMR1(const gam_rc_t & g) void cpu::addToMMR1(const gam_rc_t & g)
{ {
if (g.mmr1_update.has_value()) { if (!b->isMMR1Locked() && g.mmr1_update.has_value()) {
assert(g.mmr1_update.value().delta); assert(g.mmr1_update.value().delta);
b->addToMMR1(g.mmr1_update.value().delta, g.mmr1_update.value().reg); b->addToMMR1(g.mmr1_update.value().delta, g.mmr1_update.value().reg);
@ -1644,9 +1644,11 @@ bool cpu::misc_operations(const uint16_t instr)
// PUSH link // PUSH link
pushStack(getRegister(link_reg)); pushStack(getRegister(link_reg));
b->addToMMR1(-2, 6); if (!b->isMMR1Locked()) {
b->addToMMR1(-2, 6);
addToMMR1(a); addToMMR1(a);
}
// MOVE PC,link // MOVE PC,link
setRegister(link_reg, getPC()); setRegister(link_reg, getPC());
@ -2253,11 +2255,11 @@ void cpu::step_a()
{ {
it_is_a_trap = false; it_is_a_trap = false;
if ((b->getMMR0() & 0160000) == 0) if (!b->isMMR1Locked())
b->clearMMR1(); b->clearMMR1();
if (any_queued_interrupts && check_queued_interrupts()) { if (any_queued_interrupts && check_queued_interrupts()) {
if ((b->getMMR0() & 0160000) == 0) if (!b->isMMR1Locked())
b->clearMMR1(); b->clearMMR1();
} }
} }
@ -2269,7 +2271,7 @@ void cpu::step_b()
try { try {
uint16_t temp_pc = getPC(); uint16_t temp_pc = getPC();
if ((b->getMMR0() & 0160000) == 0) if (!b->isMMR1Locked())
b->setMMR2(temp_pc); b->setMMR2(temp_pc);
uint16_t instr = b->readWord(temp_pc); uint16_t instr = b->readWord(temp_pc);