mirror of
https://github.com/TomHarte/CLK.git
synced 2024-12-27 01:31:42 +00:00
69 lines
1.5 KiB
C++
69 lines
1.5 KiB
C++
//
|
|
// SN76489.hpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 26/02/2018.
|
|
// Copyright 2018 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#ifndef SN76489_hpp
|
|
#define SN76489_hpp
|
|
|
|
#include "../../Outputs/Speaker/Implementation/SampleSource.hpp"
|
|
#include "../../Concurrency/AsyncTaskQueue.hpp"
|
|
|
|
namespace TI {
|
|
|
|
class SN76489: public Outputs::Speaker::SampleSource {
|
|
public:
|
|
enum class Personality {
|
|
SN76489,
|
|
SN76494,
|
|
SMS
|
|
};
|
|
|
|
/// Creates a new SN76489.
|
|
SN76489(Personality personality, Concurrency::DeferringAsyncTaskQueue &task_queue, int additional_divider = 1);
|
|
|
|
/// Writes a new value to the SN76489.
|
|
void write(uint8_t value);
|
|
|
|
// As per SampleSource.
|
|
void get_samples(std::size_t number_of_samples, std::int16_t *target);
|
|
bool is_zero_level();
|
|
void set_sample_volume_range(std::int16_t range);
|
|
|
|
private:
|
|
int master_divider_ = 0;
|
|
int master_divider_period_ = 16;
|
|
int16_t output_volume_ = 0;
|
|
void evaluate_output_volume();
|
|
int volumes_[16];
|
|
|
|
Concurrency::DeferringAsyncTaskQueue &task_queue_;
|
|
|
|
struct ToneChannel {
|
|
// Programmatically-set state; updated by the processor.
|
|
uint16_t divider = 0;
|
|
uint8_t volume = 0xf;
|
|
|
|
// Active state; self-evolving as a function of time.
|
|
uint16_t counter = 0;
|
|
int level = 0;
|
|
} channels_[4];
|
|
enum {
|
|
Periodic15,
|
|
Periodic16,
|
|
Noise15,
|
|
Noise16
|
|
} noise_mode_ = Periodic15;
|
|
uint16_t noise_shifter_ = 0;
|
|
int active_register_ = 0;
|
|
|
|
bool shifter_is_16bit_ = false;
|
|
};
|
|
|
|
}
|
|
|
|
#endif /* SN76489_hpp */
|