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Starts trying to ensure appropriate address wrapping.

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This commit is contained in:
Thomas Harte 2020-10-12 22:33:43 -04:00
parent 6a47571d17
commit a15d4a156b
3 changed files with 40 additions and 17 deletions
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54
Processors/65816/Implementation/65816Implementation.hpp
View File

@ -89,8 +89,8 @@ template <typename BusHandler> void Processor<BusHandler>::run_for(const Cycles
// Data fetches and stores.
//
#define increment_data_address() data_address_ = (data_address_ & 0xff0000) + ((data_address_ + 1) & 0xffff)
#define decrement_data_address() data_address_ = (data_address_ & 0xff0000) + ((data_address_ - 1) & 0xffff)
#define increment_data_address() data_address_ = (data_address_ & ~data_address_increment_mask_) + ((data_address_ + 1) & data_address_increment_mask_)
#define decrement_data_address() data_address_ = (data_address_ & ~data_address_increment_mask_) + ((data_address_ - 1) & data_address_increment_mask_)
case CycleFetchData:
@ -229,18 +229,22 @@ template <typename BusHandler> void Processor<BusHandler>::run_for(const Cycles
case OperationConstructAbsolute:
data_address_ = instruction_buffer_.value + data_bank_;
data_address_increment_mask_ = 0xff'ff'ff;
continue;
case OperationConstructAbsoluteLong:
data_address_ = instruction_buffer_.value;
data_address_increment_mask_ = 0xff'ff'ff;
continue;
case OperationConstructAbsoluteIndexedIndirect:
data_address_ = (instruction_buffer_.value + x()) & 0xffff;
data_address_increment_mask_ = 0x00'ff'ff;
continue;
case OperationConstructAbsoluteLongX:
data_address_ = (instruction_buffer_.value + x()) & 0xffff + instruction_buffer_.value & 0xff0000;
data_address_ = instruction_buffer_.value + x();
data_address_increment_mask_ = 0xff'ff'ff;
continue;
case OperationConstructAbsoluteXRead:
@ -252,6 +256,7 @@ template <typename BusHandler> void Processor<BusHandler>::run_for(const Cycles
if(operation == OperationConstructAbsoluteXRead && data_address_ == incorrect_data_address_) {
++next_op_;
}
data_address_increment_mask_ = 0xff'ff'ff;
continue;
case OperationConstructAbsoluteYRead:
@ -263,10 +268,13 @@ template <typename BusHandler> void Processor<BusHandler>::run_for(const Cycles
if(operation == OperationConstructAbsoluteYRead && data_address_ == incorrect_data_address_) {
++next_op_;
}
data_address_increment_mask_ = 0xff'ff'ff;
continue;
case OperationConstructDirect:
// TODO: is this address correct in emulation mode when the low byte is zero?
data_address_ = (direct_ + instruction_buffer_.value) & 0xffff;
data_address_increment_mask_ = 0x00'ff'ff;
if(!(direct_&0xff)) {
++next_op_;
}
@ -277,62 +285,74 @@ template <typename BusHandler> void Processor<BusHandler>::run_for(const Cycles
((direct_ + x() + instruction_buffer_.value) & e_masks_[1]) +
(direct_ & e_masks_[0])
) & 0xffff;
data_address_increment_mask_ = 0x00'ff'ff;
if(!(direct_&0xff)) {
++next_op_;
}
continue;
case OperationConstructDirectIndirect:
data_address_ = data_bank_ + (direct_ + instruction_buffer_.value) & 0xffff;
case OperationConstructDirectIndirect: // TODO: seems very incorrect. Check this and the programs that use it;
// 12 looks wrong, the others look correct?
data_address_ = (direct_ + instruction_buffer_.value) & 0xffff;
data_address_increment_mask_ = 0x00'ff'ff;
if(!(direct_&0xff)) {
++next_op_;
}
continue;
case OperationConstructDirectIndirectIndexedLong:
// TODO: assumed here is that the low 16-bit calculation can't carry into
// the high byte. Test this!
data_address_ = (y() + instruction_buffer_.value) & 0xffff + instruction_buffer_.value & 0xff0000;
data_address_ = y() + instruction_buffer_.value;
data_address_increment_mask_ = 0xff'ff'ff;
continue;
case OperationConstructDirectIndirectLong:
data_address_ = instruction_buffer_.value;
data_address_increment_mask_ = 0xff'ff'ff;
continue;
case OperationConstructDirectX: {
// TODO: confirm incorrect_data_address_ below.
case OperationConstructDirectX:
data_address_ = (
(direct_ & e_masks_[0]) +
((instruction_buffer_.value + direct_ + x()) & e_masks_[1])
) & 0xffff;
data_address_increment_mask_ = 0x00'ff'ff;
incorrect_data_address_ = (direct_ & 0xff00) + (data_address_ & 0x00ff);
if(!(direct_&0xff)) {
++next_op_;
}
} continue;
continue;
case OperationConstructDirectY:
data_address_ = (
(direct_ & e_masks_[0]) +
((instruction_buffer_.value + direct_ + y()) & e_masks_[1])
) & 0xffff;
// TODO: given the 16-bit internal arithmetic, confirm this is the correct spurious address.
data_address_increment_mask_ = 0x00'ff'ff;
incorrect_data_address_ = (direct_ & 0xff00) + (data_address_ & 0x00ff);
if(!(direct_&0xff)) {
++next_op_;
}
continue;
case OperationConstructPER:
data_buffer_.value = instruction_buffer_.value + pc_;
data_buffer_.size = 2;
continue;
case OperationConstructStackRelative:
data_address_ = (s_.full + instruction_buffer_.value) & 0xffff;
data_address_increment_mask_ = 0x00'ff'ff;
continue;
case OperationConstructStackRelativeIndexedIndirect:
data_address_ = data_bank_ + (instruction_buffer_.value + y()) & 0xffff;
data_address_ = (instruction_buffer_.value + y()) & 0xffff;
data_address_increment_mask_ = 0xff'ff'ff;
continue;
case OperationConstructPER:
data_buffer_.value = instruction_buffer_.value + pc_;
data_buffer_.size = 2;
continue;
case OperationPrepareException: {

2
Processors/65816/Implementation/65816Storage.cpp
View File

@ -238,6 +238,7 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
target(CycleFetchPC); // New AAH.
target(OperationConstructAbsolute); // Calculate data address.
// TODO: needs to apply a 16-bit limit here:
target(CycleFetchIncrementData); // New PCL
target(CycleFetchIncrementData); // New PCH
target(CycleFetchData); // New PBR
@ -251,6 +252,7 @@ struct CPU::WDC65816::ProcessorStorageConstructor {
target(CycleFetchPC); // New AAH.
target(OperationConstructAbsolute); // Calculate data address.
// TODO: needs to apply a 16-bit limit here:
target(CycleFetchIncrementData); // New PCL
target(CycleFetchData); // New PCH

1
Processors/65816/Implementation/65816Storage.hpp
View File

@ -328,6 +328,7 @@ struct ProcessorStorage {
};
Buffer instruction_buffer_, data_buffer_;
uint32_t data_address_;
uint32_t data_address_increment_mask_ = 0xffff;
uint32_t incorrect_data_address_;
std::vector<MicroOp> micro_ops_;