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Exposes non-BusOperation bus outputs.

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This commit is contained in:
Thomas Harte 2020-10-16 21:05:42 -04:00
parent 334e0666b7
commit 096add7551
4 changed files with 40 additions and 1 deletions
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18
Processors/65816/65816.hpp
View File

@ -25,6 +25,13 @@ using BusOperation = CPU::MOS6502Esque::BusOperation;
using Register = CPU::MOS6502Esque::Register;
using Flag = CPU::MOS6502Esque::Flag;
enum ExtendedBusOutput {
Emulation = (1 << 0),
MemorySize = (1 << 1),
IndexSize = (1 << 2),
MemoryLock = (1 << 3),
};
#include "Implementation/65816Storage.hpp"
class ProcessorBase: protected ProcessorStorage {
@ -35,9 +42,18 @@ class ProcessorBase: protected ProcessorStorage {
inline void set_reset_line(bool);
inline void set_abort_line(bool);
inline bool get_is_resetting() const;
void set_value_of_register(Register r, uint16_t value);
/*!
Returns the current state of all lines not ordinarily pushed to the BusHandler.
*/
inline int get_extended_bus_output();
/*!
Provided for symmetry with the 6502; a 65816 is never jammed.
*/
inline bool is_jammed() const;
void set_value_of_register(Register r, uint16_t value);
uint16_t get_value_of_register(Register r) const;
};

17
Processors/65816/Implementation/65816Implementation.hpp
View File

@ -55,6 +55,7 @@ template <typename BusHandler, bool uses_ready_line> void Processor<BusHandler,
instruction_buffer_.clear();
data_buffer_.clear();
last_operation_pc_ = registers_.pc;
memory_lock_ = false;
} continue;
case OperationDecode: {
@ -176,6 +177,14 @@ template <typename BusHandler, bool uses_ready_line> void Processor<BusHandler,
#undef stack_access
//
// Memory lock control.
//
case OperationSetMemoryLock:
memory_lock_ = true;
continue;
//
// STP and WAI.
//
@ -985,3 +994,11 @@ bool ProcessorBase::is_jammed() const { return false; }
bool ProcessorBase::get_is_resetting() const {
return pending_exceptions_ & (Reset | PowerOn);
}
int ProcessorBase::get_extended_bus_output() {
return
(memory_lock_ ? ExtendedBusOutput::MemoryLock : 0) |
(registers_.mx_flags[0] ? ExtendedBusOutput::MemorySize : 0) |
(registers_.mx_flags[1] ? ExtendedBusOutput::IndexSize : 0) |
(registers_.emulation_flag ? ExtendedBusOutput::Emulation : 0);
}

2
Processors/65816/Implementation/65816Storage.cpp
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@ -156,6 +156,8 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
}
static void read_modify_write(bool is8bit, const std::function<void(MicroOp)> &target) {
target(OperationSetMemoryLock);
if(!is8bit) target(CycleFetchIncrementData); // Data low.
target(CycleFetchData); // Data [high].

4
Processors/65816/Implementation/65816Storage.hpp
View File

@ -149,6 +149,9 @@ enum MicroOp: uint8_t {
/// address register.
OperationPrepareException,
/// Sets the memory lock output for the rest of this instruction.
OperationSetMemoryLock,
/// Complete this set of micr-ops.
OperationMoveToNextProgram,
@ -289,6 +292,7 @@ struct ProcessorStorage {
int selected_exceptions_ = 0;
bool ready_line_ = false;
bool memory_lock_ = false;
// Just to be safe.
static_assert(PowerOn != IRQ);