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Made an attempt at implementing all three modes of IRQ.

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This commit is contained in:
Thomas Harte 2017-06-03 17:07:05 -04:00
parent 1c0130fd02
commit a2ec902773
1 changed files with 37 additions and 5 deletions
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42
Processors/Z80/Z80.hpp
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@ -68,7 +68,7 @@ enum BusOperation {
Read, Write,
Input, Output,
Interrupt,
// BusRequest, BusAcknowledge,
BusAcknowledge,
Internal
};
@ -83,6 +83,7 @@ struct MicroOp {
enum Type {
BusOperation,
DecodeOperation,
DecodeOperationNoRChange,
MoveToNextProgram,
Increment8,
@ -133,6 +134,7 @@ struct MicroOp {
BeginNMI,
BeginIRQ,
BeginIRQMode0,
RETN,
HALT,
@ -177,6 +179,7 @@ template <class T> class Processor: public MicroOpScheduler<MicroOp> {
RegisterPair ix_, iy_, pc_, sp_;
bool iff1_, iff2_;
int interrupt_mode_;
uint16_t pc_increment_;
uint8_t sign_result_; // the sign flag is set if the value in sign_result_ is negative
uint8_t zero_result_; // the zero flag is set if the value in zero_result_ is zero
uint8_t half_carry_result_; // the half-carry flag is set if bit 4 of half_carry_result_ is set
@ -316,7 +319,7 @@ template <class T> class Processor: public MicroOpScheduler<MicroOp> {
#define WAIT(n) {MicroOp::BusOperation, nullptr, nullptr, {Internal, n} }
#define Program(...) { __VA_ARGS__, {MicroOp::MoveToNextProgram} }
#define isTerminal(n) (n == MicroOp::MoveToNextProgram || n == MicroOp::DecodeOperation)
#define isTerminal(n) (n == MicroOp::MoveToNextProgram || n == MicroOp::DecodeOperation || n == MicroOp::DecodeOperationNoRChange)
typedef MicroOp InstructionTable[256][20];
@ -672,7 +675,8 @@ template <class T> class Processor: public MicroOpScheduler<MicroOp> {
number_of_cycles_(0),
request_status_(Interrupt::PowerOn),
last_request_status_(Interrupt::PowerOn),
irq_line_(false) {
irq_line_(false),
pc_increment_(1) {
set_flags(0xff);
assemble_base_page(base_page_, hl_, false, cb_page_);
@ -699,9 +703,32 @@ template <class T> class Processor: public MicroOpScheduler<MicroOp> {
PUSH(pc_),
{ MicroOp::MoveToNextProgram }
};
MicroOp irq_mode0_program[] = {
{ MicroOp::BeginIRQMode0 },
{ MicroOp::BusOperation, nullptr, nullptr, {BusOperation::Interrupt, 7, nullptr, &operation_}},
{ MicroOp::DecodeOperationNoRChange }
};
MicroOp irq_mode1_program[] = {
{ MicroOp::BeginIRQ },
{ MicroOp::BusOperation, nullptr, nullptr, {BusOperation::Interrupt, 7, nullptr, &operation_}},
PUSH(pc_),
{ MicroOp::Move16, &temp16_.full, &pc_.full },
{ MicroOp::MoveToNextProgram }
};
MicroOp irq_mode2_program[] = {
{ MicroOp::BeginIRQ },
{ MicroOp::BusOperation, nullptr, nullptr, {BusOperation::Interrupt, 7, nullptr, &temp16_.bytes.low}},
PUSH(pc_),
{ MicroOp::Move8, &i_, &temp16_.bytes.high },
FETCH16L(pc_, temp16_),
{ MicroOp::MoveToNextProgram }
};
copy_program(reset_program, reset_program_);
copy_program(nmi_program, nmi_program_);
copy_program(irq_mode0_program, irq_program_[0]);
copy_program(irq_mode1_program, irq_program_[1]);
copy_program(irq_mode2_program, irq_program_[2]);
}
/*!
@ -716,6 +743,7 @@ template <class T> class Processor: public MicroOpScheduler<MicroOp> {
void run_for_cycles(int number_of_cycles) {
#define advance_operation() \
pc_increment_ = 1; \
if(last_request_status_) { \
halt_mask_ = 0xff; \
if(last_request_status_ & (Interrupt::PowerOn | Interrupt::Reset)) { \
@ -759,12 +787,13 @@ template <class T> class Processor: public MicroOpScheduler<MicroOp> {
break;
case MicroOp::DecodeOperation:
r_ = (r_ & 0x80) | ((r_ + current_instruction_page_->r_step_) & 0x7f);
pc_.full++;
pc_.full += pc_increment_;
case MicroOp::DecodeOperationNoRChange:
scheduled_program_counter_ = current_instruction_page_->instructions[operation_ & halt_mask_];
break;
case MicroOp::Increment16: (*(uint16_t *)operation->source)++; break;
case MicroOp::IncrementPC: pc_.full++; break;
case MicroOp::IncrementPC: pc_.full += pc_increment_; break;
case MicroOp::Decrement16: (*(uint16_t *)operation->source)--; break;
case MicroOp::Move8: *(uint8_t *)operation->destination = *(uint8_t *)operation->source; break;
case MicroOp::Move16: *(uint16_t *)operation->destination = *(uint16_t *)operation->source; break;
@ -1433,9 +1462,12 @@ template <class T> class Processor: public MicroOpScheduler<MicroOp> {
#pragma mark - Special-case Flow
case MicroOp::BeginIRQMode0:
pc_increment_ = 0; // deliberate fallthrough
case MicroOp::BeginIRQ:
iff2_ = iff1_ = false;
request_status_ &= ~Interrupt::IRQ;
temp16_.full = 0x38;
break;
case MicroOp::BeginNMI: