6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2024-11-26 08:49:37 +00:00
Code Issues Projects Releases Wiki Activity

Add a call to set register state with population of the prefetch.

Browse Source
This commit is contained in:
Thomas Harte 2022-05-25 20:22:05 -04:00
parent 64491525b4
commit 367ad8079a
2 changed files with 32 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
Processors/68000Mk2/68000Mk2.hpp
View File

@ -397,9 +397,18 @@ class Processor: private ProcessorBase {
void run_for(HalfCycles duration);
/// @returns The current processor state.
CPU::MC68000Mk2::State get_state();
/// Sets the current processor state.
void set_state(const CPU::MC68000Mk2::State &);
/// Sets all registers to the values provided, fills the prefetch queue and ensures the
/// next action the processor will take is to decode whatever is in the queue.
///
/// The queue is filled synchronously, during this call, causing calls to the bus handler.
void decode_from_state(const InstructionSet::M68k::RegisterSet &);
// TODO: bus ack/grant, halt,
/// Sets the DTack line — @c true for active, @c false for inactive.

23
Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp
View File

@ -2615,6 +2615,29 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
did_update_status();
}
template <class BusHandler, bool dtack_is_implicit, bool permit_overrun, bool signal_will_perform>
void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perform>::decode_from_state(const InstructionSet::M68k::RegisterSet &registers) {
// Populate registers.
CPU::MC68000Mk2::State state;
state.registers = registers;
set_state(state);
// Ensure the state machine will resume at decode.
state_ = Decode;
// Fill the prefetch queue.
captured_interrupt_level_ = bus_interrupt_level_;
read_program.value = &prefetch_.high;
bus_handler_.perform_bus_operation(read_program_announce, is_supervisor_);
bus_handler_.perform_bus_operation(read_program, is_supervisor_);
program_counter_.l += 2;
read_program.value = &prefetch_.low;
bus_handler_.perform_bus_operation(read_program_announce, is_supervisor_);
bus_handler_.perform_bus_operation(read_program, is_supervisor_);
program_counter_.l += 2;
}
}
}