mirror of
https://github.com/TomHarte/CLK.git
synced 2024-12-27 01:31:42 +00:00
The actual work begins: starts implementing 65816 micro-ops.
This commit is contained in:
parent
ef1a514785
commit
78b3ec4b10
@ -29,6 +29,7 @@ class ProcessorBase: protected ProcessorStorage {
|
||||
inline void set_power_on(bool);
|
||||
inline void set_irq_line(bool);
|
||||
inline void set_nmi_line(bool);
|
||||
inline void set_reset_line(bool);
|
||||
void set_value_of_register(Register r, uint16_t value);
|
||||
|
||||
inline bool is_jammed() const;
|
||||
|
@ -12,25 +12,25 @@ using namespace CPU::WDC65816;
|
||||
|
||||
uint16_t ProcessorBase::get_value_of_register(Register r) const {
|
||||
switch (r) {
|
||||
// case Register::ProgramCounter: return pc_.full;
|
||||
// case Register::LastOperationAddress: return last_operation_pc_.full;
|
||||
// case Register::StackPointer: return s_;
|
||||
case Register::ProgramCounter: return pc_;
|
||||
case Register::LastOperationAddress: return last_operation_pc_;
|
||||
case Register::StackPointer: return s_;
|
||||
// case Register::Flags: return get_flags();
|
||||
// case Register::A: return a_;
|
||||
// case Register::X: return x_;
|
||||
// case Register::Y: return y_;
|
||||
case Register::A: return a_.full;
|
||||
case Register::X: return x_.full;
|
||||
case Register::Y: return y_.full;
|
||||
default: return 0;
|
||||
}
|
||||
}
|
||||
|
||||
void ProcessorBase::set_value_of_register(Register r, uint16_t value) {
|
||||
switch (r) {
|
||||
// case Register::ProgramCounter: pc_.full = value; break;
|
||||
// case Register::StackPointer: s_ = uint8_t(value); break;
|
||||
case Register::ProgramCounter: pc_ = value; break;
|
||||
case Register::StackPointer: s_ = value; break;
|
||||
// case Register::Flags: set_flags(uint8_t(value)); break;
|
||||
// case Register::A: a_ = uint8_t(value); break;
|
||||
// case Register::X: x_ = uint8_t(value); break;
|
||||
// case Register::Y: y_ = uint8_t(value); break;
|
||||
case Register::A: a_ = value; break;
|
||||
case Register::X: x_ = value; break;
|
||||
case Register::Y: y_ = value; break;
|
||||
default: break;
|
||||
}
|
||||
}
|
||||
|
@ -7,28 +7,130 @@
|
||||
//
|
||||
|
||||
template <typename BusHandler> void Processor<BusHandler>::run_for(const Cycles cycles) {
|
||||
auto int_cycles = cycles.as_integral();
|
||||
while(int_cycles--) {
|
||||
// Temporary storage for the next bus cycle.
|
||||
uint32_t bus_address = 0;
|
||||
uint8_t *bus_value = nullptr;
|
||||
uint8_t throwaway = 0;
|
||||
BusOperation bus_operation = BusOperation::None;
|
||||
|
||||
Cycles number_of_cycles = cycles + cycles_left_to_run_;
|
||||
while(number_of_cycles > Cycles(0)) {
|
||||
const MicroOp operation = *next_op_;
|
||||
++next_op_;
|
||||
|
||||
switch(operation) {
|
||||
|
||||
//
|
||||
// Scheduling.
|
||||
//
|
||||
|
||||
case OperationMoveToNextProgram:
|
||||
// The exception program will determine the appropriate way to respond
|
||||
// based on the pending exception if one exists; otherwise just do a
|
||||
// standard fetch-decode-execute.
|
||||
next_op_ = µ_ops_[instructions[pending_exceptions_ ? size_t(OperationSlot::Exception) : size_t(OperationSlot::FetchDecodeExecute)].program_offset];
|
||||
|
||||
// TODO: reset instruction buffer.
|
||||
instruction_buffer_.clear();
|
||||
data_buffer_.clear();
|
||||
last_operation_pc_ = pc_;
|
||||
continue;
|
||||
|
||||
case OperationDecode:
|
||||
// A VERY TEMPORARY piece of logging.
|
||||
printf("%02x\n", instruction_buffer_.value);
|
||||
active_instruction_ = &instructions[instruction_buffer_.value];
|
||||
next_op_ = µ_ops_[active_instruction_->program_offset];
|
||||
instruction_buffer_.clear();
|
||||
continue;
|
||||
|
||||
//
|
||||
// PC fetches.
|
||||
//
|
||||
|
||||
case CycleFetchIncrementPC:
|
||||
bus_address = pc_ | program_bank_;
|
||||
bus_value = instruction_buffer_.next();
|
||||
bus_operation = MOS6502Esque::Read; // TODO: indicate ReadOpcode when appropriate.
|
||||
++pc_;
|
||||
break;
|
||||
|
||||
case CycleFetchPC:
|
||||
bus_address = pc_ | program_bank_;
|
||||
bus_value = &throwaway;
|
||||
bus_operation = MOS6502Esque::Read;
|
||||
break;
|
||||
|
||||
//
|
||||
// Data movement.
|
||||
//
|
||||
|
||||
case OperationCopyPCToData:
|
||||
data_buffer_.size = 2;
|
||||
data_buffer_.value = pc_;
|
||||
break;
|
||||
|
||||
case OperationCopyInstructionToData:
|
||||
data_buffer_ = instruction_buffer_;
|
||||
break;
|
||||
|
||||
//
|
||||
// Performance.
|
||||
//
|
||||
|
||||
case OperationPerform:
|
||||
switch(active_instruction_->operation) {
|
||||
case CLD:
|
||||
// TODO.
|
||||
break;
|
||||
|
||||
case LDX:
|
||||
// TODO.
|
||||
break;
|
||||
|
||||
default:
|
||||
assert(false);
|
||||
}
|
||||
break;
|
||||
|
||||
default:
|
||||
assert(false);
|
||||
}
|
||||
|
||||
number_of_cycles -= bus_handler_.perform_bus_operation(bus_operation, bus_address, bus_value);
|
||||
}
|
||||
|
||||
cycles_left_to_run_ = number_of_cycles;
|
||||
}
|
||||
|
||||
void ProcessorBase::set_power_on(bool active) {
|
||||
if(active) {
|
||||
pending_exceptions_ |= PowerOn;
|
||||
} else {
|
||||
pending_exceptions_ &= ~PowerOn;
|
||||
}
|
||||
}
|
||||
|
||||
void ProcessorBase::set_power_on(bool) {}
|
||||
void ProcessorBase::set_irq_line(bool) {}
|
||||
void ProcessorBase::set_nmi_line(bool) {}
|
||||
void ProcessorBase::set_irq_line(bool active) {
|
||||
if(active) {
|
||||
pending_exceptions_ |= IRQ;
|
||||
} else {
|
||||
pending_exceptions_ &= ~IRQ;
|
||||
}
|
||||
}
|
||||
|
||||
void ProcessorBase::set_reset_line(bool active) {
|
||||
if(active) {
|
||||
pending_exceptions_ |= Reset;
|
||||
} else {
|
||||
pending_exceptions_ &= ~Reset;
|
||||
}
|
||||
}
|
||||
|
||||
void ProcessorBase::set_nmi_line(bool active) {
|
||||
// This is edge triggered.
|
||||
if(active) {
|
||||
pending_exceptions_ |= NMI;
|
||||
}
|
||||
}
|
||||
|
||||
// The 65816 can't jam.
|
||||
bool ProcessorBase::is_jammed() const { return false; }
|
||||
|
@ -988,6 +988,10 @@ ProcessorStorage::ProcessorStorage() {
|
||||
constructor.set_exception_generator(&ProcessorStorageConstructor::stack_exception);
|
||||
constructor.install_fetch_decode_execute();
|
||||
|
||||
// Find any OperationMoveToNextProgram.
|
||||
next_op_ = micro_ops_.data();
|
||||
while(*next_op_ != OperationMoveToNextProgram) ++next_op_;
|
||||
|
||||
#ifndef NDEBUG
|
||||
assert(micro_ops_.size() < 65536);
|
||||
printf("Generated %zd micro-ops in total; covered %d opcodes\n", micro_ops_.size(), constructor.opcode);
|
||||
|
@ -185,34 +185,29 @@ struct ProcessorStorage {
|
||||
FetchDecodeExecute
|
||||
};
|
||||
|
||||
void set_power_on(bool power_on) {
|
||||
if(power_on) {
|
||||
// Set next_op_ to start the exception program.
|
||||
next_op_ = µ_ops_[instructions[size_t(OperationSlot::Exception)].program_offset];
|
||||
pending_exceptions_ = PowerOn;
|
||||
} else {
|
||||
pending_exceptions_ &= ~PowerOn;
|
||||
}
|
||||
}
|
||||
|
||||
// Registers.
|
||||
RegisterPair16 a_;
|
||||
RegisterPair16 x_, y_;
|
||||
uint16_t pc_, s_;
|
||||
|
||||
// A helper for testing.
|
||||
uint16_t last_operation_pc_;
|
||||
Instruction *active_instruction_;
|
||||
Cycles cycles_left_to_run_;
|
||||
|
||||
// I.e. the offset for direct addressing (outside of emulation mode).
|
||||
uint16_t direct_;
|
||||
uint16_t direct_ = 0;
|
||||
|
||||
// Banking registers are all stored with the relevant byte
|
||||
// shifted up bits 16–23.
|
||||
uint32_t data_bank_; // i.e. DBR.
|
||||
uint32_t program_bank_; // i.e. PBR.
|
||||
uint32_t data_bank_ = 0; // i.e. DBR.
|
||||
uint32_t program_bank_ = 0; // i.e. PBR.
|
||||
|
||||
static constexpr int PowerOn = 1 << 0;
|
||||
static constexpr int Reset = 1 << 1;
|
||||
static constexpr int IRQ = 1 << 2;
|
||||
static constexpr int NMI = 1 << 3;
|
||||
int pending_exceptions_ = 0;
|
||||
int pending_exceptions_ = PowerOn; // By default.
|
||||
|
||||
/// Defines a four-byte buffer which can be cleared or filled in single-byte increments from least significant byte
|
||||
/// to most significant.
|
||||
|
Loading…
Reference in New Issue
Block a user