Attmept full ADC implementation.

Components/uPD7002/uPD7002.cpp

@@ -10,22 +10,61 @@
 
 using namespace NEC;
 
-uPD7002::uPD7002(HalfCycles) {
+uPD7002::uPD7002(const HalfCycles clock_rate) {
+	// Per the BBC AUG: "8 bit conversions typically take 4 ms to complete whereas 10 bit
+	// conversions typically take 10 ms to complete".
+	fast_period_ = clock_rate / 250;
+	slow_period_ = clock_rate / 100;
 }
 
-void uPD7002::run_for(HalfCycles) {
+void uPD7002::run_for(const HalfCycles count) {
+	if(!conversion_time_remaining_) {
+		return;
+	}
+
+	if(count >= conversion_time_remaining_) {
+		conversion_time_remaining_ = HalfCycles(0);
+		interrupt_ = true;
+		result_ = uint16_t(inputs_[channel_] * 65535.0f) & (high_precision_ ? 0xfff0 : 0xff00);
+		if(delegate_) delegate_->did_change_interrupt_status(*this);
+		return;
+	}
+
+	conversion_time_remaining_ -= count;
 }
 
 bool uPD7002::interrupt() const {
-	return false;
+	return interrupt_;
 }
 
 void uPD7002::write(const uint16_t address, const uint8_t value) {
-	(void)address;
-	(void)value;
+	if(!address) {
+		channel_ = value & 3;
+		high_precision_ = value & 8;
+		conversion_time_remaining_ = high_precision_ ? slow_period_ : fast_period_;
+		return;
+	}
 }
 
 uint8_t uPD7002::read(const uint16_t address) {
-	(void)address;
-	return 0xff;
+	if(!address) {
+		return status();
+	}
+
+	if(address & 1) {
+		interrupt_ = false;
+		if(delegate_) delegate_->did_change_interrupt_status(*this);
+		return uint8_t(result_ >> 8);
+	} else {
+		return uint8_t(result_);
+	}
+}
+
+uint8_t uPD7002::status() const {
+	return
+		channel_ |
+		(high_precision_ ? 8 : 0) |
+		((result_ >> 10) & 0x30) |
+		(conversion_time_remaining_ > HalfCycles(0) ? 0x00 : 0x40) |
+		(interrupt_ ? 0x00 : 0x80);
 }

Components/uPD7002/uPD7002.hpp

@@ -18,13 +18,28 @@ public:
 	bool interrupt() const;
 
 	struct Delegate {
-	virtual void did_change_interrupt_status(uPD7002 &);
+	virtual void did_change_interrupt_status(uPD7002 &) = 0;
 	};
+	void set_delegate(Delegate *);
 
 	void write(uint16_t address, uint8_t value);
 	uint8_t read(uint16_t address);
 
+	void set_input(int channel, float value);
+
 private:
+	float inputs_[4]{};
+	uint16_t result_ = 0;
+	bool interrupt_ = false;
+
+	uint8_t channel_ = 0;
+	bool high_precision_ = false;
+
+	HalfCycles conversion_time_remaining_;
+	HalfCycles fast_period_, slow_period_;
+
+	uint8_t status() const;
+	Delegate *delegate_ = nullptr;
 };
 
 }

Machines/Acorn/BBCMicro/BBCMicro.cpp

@@ -440,7 +440,8 @@ class ConcreteMachine:
 	public MachineTypes::MappedKeyboardMachine,
 	public MachineTypes::ScanProducer,
 	public MachineTypes::TimedMachine,
-	public MOS::MOS6522::IRQDelegatePortHandler::Delegate
+	public MOS::MOS6522::IRQDelegatePortHandler::Delegate,
+	public NEC::uPD7002::Delegate
 {
 public:
 	ConcreteMachine(
@@ -615,10 +616,8 @@ public:
 				}
 			} else if(address >= 0xfec0 && address < 0xfee0) {
 				if(is_read(operation)) {
-//					Logger::info().append("ACIA read");
 					*value = adc_.read(address);
 				} else {
-//					Logger::info().append("ACIA write: %02x", *value);
 					adc_.write(address, *value);
 				}
 			}
@@ -698,6 +697,11 @@ private:
 		update_irq_line();
 	}
 
+	// MARK: - uPD7002::Delegate.
+	void did_change_interrupt_status(NEC::uPD7002 &) override {
+		update_irq_line();
+	}
+
 	// MARK: - Clock phase.
 	int phase_ = 0;