diff --git a/Processors/68000/Implementation/68000Implementation.hpp b/Processors/68000/Implementation/68000Implementation.hpp index 61ad19098..9ca26b4e3 100644 --- a/Processors/68000/Implementation/68000Implementation.hpp +++ b/Processors/68000/Implementation/68000Implementation.hpp @@ -31,14 +31,38 @@ template void Processor: /* PERFORM THE BUS STEP'S ACTION. */ - // Consider advancing a micro-operation. - if(active_step_->is_terminal()) { - // If there are any more micro-operations available, just move onwards. - if(active_micro_op_) { - ++active_micro_op_; + if(!active_step_->is_terminal()) { + switch(active_step_->action) { + default: + std::cerr << "Unimplemented 68000 bus step action: " << int(active_step_->action) << std::endl; + return; + break; + + case BusStep::Action::None: break; + + case BusStep::Action::IncrementEffectiveAddress: effective_address_ += 2; break; + case BusStep::Action::IncrementProgramCounter: program_counter_.full += 2; break; + + case BusStep::Action::AdvancePrefetch: + prefetch_queue_[0] = prefetch_queue_[1]; + break; } - if(!active_micro_op_ || active_micro_op_->is_terminal()) { + // Move to the next bus step. + ++ active_step_; + + // Skip the micro-op renavigation below. + continue; + } + + /* + FIND THE NEXT MICRO-OP. + */ + while(true) { + // If there are any more micro-operations available, just move onwards. + if(active_micro_op_ && !active_micro_op_->is_terminal()) { + ++active_micro_op_; + } else { // Either the micro-operations for this instruction have been exhausted, or // no instruction was ongoing. Either way, do a standard instruction operation. @@ -54,8 +78,6 @@ template void Processor: active_micro_op_ = active_program_->micro_operations; } - // There is now a micro operation; cue up the first step and perform the predecessor action. - active_step_ = active_micro_op_->bus_program; switch(active_micro_op_->action) { case MicroOp::Action::None: break; @@ -139,25 +161,12 @@ template void Processor: active_program_->destination->full -= 4; break; } - } else { - switch(active_step_->action) { - default: - std::cerr << "Unimplemented 68000 bus step action: " << int(active_step_->action) << std::endl; - return; - break; - case BusStep::Action::None: break; - - case BusStep::Action::IncrementEffectiveAddress: effective_address_ += 2; break; - case BusStep::Action::IncrementProgramCounter: program_counter_.full += 2; break; - - case BusStep::Action::AdvancePrefetch: - prefetch_queue_[0] = prefetch_queue_[1]; + // If we've got to a micro-op that includes bus steps, break out of this loop. + if(!active_micro_op_->is_terminal()) { + active_step_ = active_micro_op_->bus_program; break; } - - // Move to the next bus step. - ++ active_step_; } } }