jan/rusty_emu
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Fix Intel 4004 CPU instruction set and improve MCS-4 timing accuracy

Browse source 
Overhaul the Intel 4004 instruction set to match the real opcode map,
adding missing instructions (NOP, FIM, FIN, JIN, ISZ, KBP, DCL, WR0-3,
RD0-3) and refining two-byte instruction handling with proper M1/M2
data phases.  Rewrite the CPU fetch-execute cycle to correctly process
two-byte opcodes across separate clock cycles.

Improve Intel 4001 ROM timing with M1/M2 nibble phase tracking and an
A3 wait counter so the ROM drives data only when the CPU expects it.
Fix state-machine transition helpers in Intel 4002 and 4003 to capture
the old state before processing events, preventing incorrect exit/entry
callbacks.

Add non-propagating pin driver methods to prevent deadlocks caused by
bidirectional pin connections during signal propagation.

Add Fibonacci integration test and opcode fix plan document.
Update all README files to reflect the new instruction set.
This commit is contained in:
Jan-Peter von Hunnius 2026-05-12 19:32:01 +02:00
parent 54144d10e9
commit 6a335a15d4
14 changed files with 4125 additions and 1062 deletions
Download patch file Download diff file Expand all files Collapse all files

40
src/components/memory/intel_4003.rs
View file

@ -453,56 +453,48 @@ impl Intel4003 {
/// Helper function to process latency elapsed event
fn process_latency_elapsed(&mut self) {
let old_state = self.state_machine.get_state();
let event = Intel400xEvent::LatencyElapsed;
// Use process_event_direct method to avoid borrowing conflicts
let new_state = process_event_direct(&mut self.state_machine, event);
// Handle state entry/exit manually
if new_state != self.state_machine.get_state() {
self.on_state_exit(self.state_machine.get_state());
self.state_machine.current_state = new_state;
if new_state != old_state {
self.on_state_exit(old_state);
self.on_state_entry(new_state);
}
}
/// Helper function to process chip select event
fn process_chip_select(&mut self) {
let old_state = self.state_machine.get_state();
let event = Intel400xEvent::ChipSelect;
// Use process_event_direct method to avoid borrowing conflicts
let new_state = process_event_direct(&mut self.state_machine, event);
// Handle state entry/exit manually
if new_state != self.state_machine.get_state() {
self.on_state_exit(self.state_machine.get_state());
self.state_machine.current_state = new_state;
if new_state != old_state {
self.on_state_exit(old_state);
self.on_state_entry(new_state);
}
}
/// Helper function to process operation complete event
fn process_operation_complete(&mut self) {
let old_state = self.state_machine.get_state();
let event = Intel400xEvent::OperationComplete;
// Use process_event_direct method to avoid borrowing conflicts
let new_state = process_event_direct(&mut self.state_machine, event);
// Handle state entry/exit manually
if new_state != self.state_machine.get_state() {
self.on_state_exit(self.state_machine.get_state());
self.state_machine.current_state = new_state;
if new_state != old_state {
self.on_state_exit(old_state);
self.on_state_entry(new_state);
}
}
/// Helper function to process address complete event
fn process_address_complete(&mut self) {
let old_state = self.state_machine.get_state();
let event = Intel400xEvent::AddressComplete;
// Use process_event_direct method to avoid borrowing conflicts
let new_state = process_event_direct(&mut self.state_machine, event);
// Handle state entry/exit manually
if new_state != self.state_machine.get_state() {
self.on_state_exit(self.state_machine.get_state());
self.state_machine.current_state = new_state;
if new_state != old_state {
self.on_state_exit(old_state);
self.on_state_entry(new_state);
}
}
@ -576,13 +568,11 @@ impl Component for Intel4003 {
// Process all events
for event in events {
// Use the process_event_direct method to avoid borrowing conflicts
let old_state = self.state_machine.get_state();
let new_state = process_event_direct(&mut self.state_machine, event);
// Handle state entry/exit manually
if new_state != self.state_machine.get_state() {
self.on_state_exit(self.state_machine.get_state());
self.state_machine.current_state = new_state;
if new_state != old_state {
self.on_state_exit(old_state);
self.on_state_entry(new_state);
}
}