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API Sources Tools File Format Technicals Amiga Paula emulator. [io68 library documentation.] Detailed Description Paula emulator (Amiga soundchip). About Amiga hardware registers Amiga hardware registers could have a different address for read and write access. It is the case for DMA control register (DMACON). Registers could be (B)yte or (W)ord wide. SET/CLR bit Some hardware registers work with a SET/CLEAR bit. When writing these registers the value is not copied as is. The operation depends on the value of S the most signifiant bit (#15). If S is SET then all others setted bits are setted (bitwise OR). If S is CLEAR then all others setted bits are cleared (bitwise NAND). Files file   paula_io.h   Paula IO plugin header. file   paulaemul.h   Paula emulator header. Data Structures struct   paulav_t   Paula voice information data structure. More... Amiga interruption registers All hardware registers involved with interruption handling use the same bit organisation : bit 7 Audio channel A bit 8 Audio channel B bit 9 Audio channel C bit 10 Audio channel D bit 14 Master interrupt #define  PAULA_INTREQR   0x1E   Interruption request read. #define  PAULA_INTREQRH   0x1E   Interruption request read MSB. #define  PAULA_INTREQRL   0x1F   Interruption request read LSB. #define  PAULA_INTREQ   0x9C   Interruption request write. #define  PAULA_INTREQH   0x9C   Interruption request write MSB. #define  PAULA_INTREQL   0x9D   Interruption request write LSB. #define  PAULA_INTENAR   0x1C   Interruption enable read. #define  PAULA_INTENARH   0x1C   Interruption enable read MSB. #define  PAULA_INTENARL   0x1D   Interruption enable read LSB. #define  PAULA_INTENA   0x9A   Interruption enable write. #define  PAULA_INTENAH   0x9A   Interruption enable write MSB. #define  PAULA_INTENAL   0x9B   Interruption enable write LSB. Amiga DMA registers. Amiga DMA control register bits : bit 0 Audio DMA channel A bit 1 Audio DMA channel B bit 2 Audio DMA channel C bit 3 Audio DMA channel D bit 9 General DMA #define  PAULA_DMACONR   0x02   DMA control read. #define  PAULA_DMACONRH   0x02   DMA control read MSB. #define  PAULA_DMACONRL   0x03   DMA control read LSB. #define  PAULA_DMACON   0x96   DMA control write. #define  PAULA_DMACONH   0x96   DMA control write MSB. #define  PAULA_DMACONL   0x97   DMA control write LSB. The Audio & Disk Control Registers. Bits: 07 USE3PN Use audio channel 3 to modulate nothing. 06 USE2P3 Use audio channel 2 to modulate period of channel 3. 05 USE1P2 Use audio channel 1 to modulate period of channel 2. 04 USE0P1 Use audio channel 0 to modulate period of channel 1. 03 USE3VN Use audio channel 3 to modulate nothing. 02 USE2V3 Use audio channel 2 to modulate volume of channel 3. 01 USE1V2 Use audio channel 1 to modulate volume of channel 2. 00 USE0V1 Use audio channel 0 to modulate volume of channel 1. Note: If both period/volume are modulated on the same channel, the period and volume will be alternated. First word xxxxxxxx V6-V0, Second word P15-P0 (etc). #define  PAULA_ADKCON   0x9E   Audio, disk, control write. #define  PAULA_ADKCONR   0x10   Audio, disk, control read. #define  PAULA_ADKCONRH   0x10   Audio, disk, control write. #define  PAULA_ADKCONRL   0x11   Audio, disk, control write. Amiga Paula registers. #define  PAULA_VOICE(I)   ((0xA+(I))<<4)   Paula channel I register base. #define  PAULA_VOICEA   0xA0   Paula channel A register base. #define  PAULA_VOICEB   0xB0   Paula channel B register base. #define  PAULA_VOICEC   0xC0   Paula channel C register base. #define  PAULA_VOICED   0xD0   Paula channel D register base. Amiga Paula frequencies (PAL). #define  PAULA_PER   2.79365E-7   Paula period (1 cycle duration). #define  PAULA_FRQ   3579610.53837   Paula frequency (1/PAULA_PER). Initialization functions. unsigned int  PL_sampling_rate (unsigned int f)   Set/Get sampling rate. int  PL_reset (void)   Paula hardware reset. int  PL_init (void)   Paula first one first initialization. Emulation functions void  PL_mix (u32 *b, u8 *mem68, int n)   Execute Paula emulation. Paula (Amiga soundchip) IO plugin io68_t  paula_io   Paula IO plugin instance. Internal Paula emulation data. u8  paula []   Paula regiter data storage. paulav_t  paulav []   Paula voices(channel) table (4 voices). int  paula_dmacon   Shadow DMACON. int  paula_intena   Shadow INTENA. int  paula_intreq   Shadow INTREQ. int  paula_adkcon   Shadow ADKCON. int  paula_interpol   Interpolation mode [0:none 1:linear]. Defines #define  PAULA_VHPOSR   0x06   Amiga Vertical/Horizontal electron bean position. #define  PAULA_CT_FIX   13   Counter fixed point precision 13+19(512kb)=>32 bit. Function Documentation unsigned int PL_sampling_rate (  unsigned int  f  )    Set/Get sampling rate. The PL_sampling_rate() function set Paula emulator sampling rate. f is given in hz. If f is 0 the current replay is return. Parameters: f  sampling rate in hz (0 to get current value). Returns: new sampling rate int PL_reset (  void   )    Paula hardware reset. The PL_reset() reset function perform a Paula reset. It performs following operations : all registers zeroed all internal voices set to dummy 2 samples len address. general DMA enabled all audio DMA disabled interrupt master enabled all audio interrupt disbled Returns: error-code (always success) 0 Success int PL_init (  void   )    Paula first one first initialization. The PL_init() must be call before all other PL functions. It performs following operations: Init output level (volume) table. Hardware reset Set replay frequency to default (44100 Hz) if not already set Returns: error-code (always success) 0 Success See also: PL_reset() void PL_mix (  u32 *  b, u8 *  mem68, int  n )    Execute Paula emulation. The PL_mix() function processes sample mixing with current internal parameters for n samples. Mixed samples are stored in a large enough (at least n) 32 bit pcm buffer pointed by b. mem68 is a pointer to the 68K memory buffer. The Paula emulator assume that this buffer is at least the size of the Amiga "chip" RAM. This implies at leat 512Kb and PCM data must be in the first 512Kb. Parameters: b  Pointer to destination 32-bit data buffer mem68  Pointer to 68K memory buffer start address n  Number of sample to mix in b buffer
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