// license:BSD-3-Clause // copyright-holders:Aaron Giles /*************************************************************************** dac.h DAC device emulator. ***************************************************************************/ #ifndef __DAC_H__ #define __DAC_H__ //************************************************************************** // INTERFACE CONFIGURATION MACROS //************************************************************************** #define MCFG_DAC_ADD(_tag) \ MCFG_DEVICE_ADD(_tag, DAC, 0) //************************************************************************** // TYPE DEFINITIONS //************************************************************************** // ======================> dac_device class dac_device : public device_t, public device_sound_interface { // default to 4x oversampling static const UINT32 DEFAULT_SAMPLE_RATE = 48000 * 4; public: // construction/destruction dac_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock); // public interface INT16 output() const { return m_output; } void write(INT16 data) { m_stream->update(); m_output = data; } void write_unsigned8(UINT8 data) { write(data * 32767 / 255); } // 0..255, mapped to 0..32767 void write_signed8(UINT8 data) { write((data - 0x80) * 32767 / 128); } // 0..255, mapped to -32767..32767 void write_unsigned16(UINT16 data) { write(data / 2); } // 0..65535, mapped to 0..32767 void write_signed16(UINT16 data) { write(data - 0x8000); } // 0..65535, mapped to -32768..32767 // wrappers DECLARE_WRITE8_MEMBER( write_unsigned8 ); DECLARE_WRITE8_MEMBER( write_signed8 ); protected: // device-level overrides virtual void device_start(); virtual void device_reset(); // device_sound_interface overrides virtual void sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples); // internal state sound_stream * m_stream; INT16 m_output; }; // device type definition extern const device_type DAC; #endif /* __DAC_H__ */