diff --git a/sound-driver/psg.c b/sound-driver/psg.c index 2074ec3..aa8dd30 100644 --- a/sound-driver/psg.c +++ b/sound-driver/psg.c @@ -78,11 +78,11 @@ asm volatile ( ); } -uint8_t psgReadShadow(uint8_t address) { +static uint8_t psgReadShadow(uint8_t address) { return psgShadowRegisters[address]; } -void psgWrite(uint8_t address, uint8_t data) { +static void psgWrite(uint8_t address, uint8_t data) { psgShadowRegisters[address] = data; // according to "State Timing" (p. 15) of datasheet @@ -109,7 +109,7 @@ void psgWrite(uint8_t address, uint8_t data) { BUS_OP_NACT(); } -void psgWriteFrequency(uint8_t channel, uint16_t frequencyCode) { +static void psgWriteFrequency(uint8_t channel, uint16_t frequencyCode) { psgWrite(CHANNEL_A_TONE_PERIOD_FINE_REG + (channel * 2), (frequencyCode & 0x00ff)); psgWrite(CHANNEL_A_TONE_PERIOD_COARSE_REG + (channel * 2), ((frequencyCode >> 8) & 0x000f)); } diff --git a/sound-driver/psg.h b/sound-driver/psg.h index 0d364cb..5f02aab 100644 --- a/sound-driver/psg.h +++ b/sound-driver/psg.h @@ -42,11 +42,5 @@ void psgInit(); void psgPlayTone(uint8_t channel, t_octave octave, t_note note); void psgAmplitude(uint8_t channel, uint8_t volume); -// low level -void psgWriteFrequency(uint8_t channel, uint16_t frequencyCode); - -// very low level -void psgWrite(uint8_t address, uint8_t data); -uint8_t psgReadShadow(uint8_t address); #endif // _PSG_H_ diff --git a/sound-driver/sn76489an.c b/sound-driver/sn76489an.c new file mode 100644 index 0000000..0b9ec3f --- /dev/null +++ b/sound-driver/sn76489an.c @@ -0,0 +1,94 @@ +#include +#include +#include + +#include "psg.h" +#include "scheduler.h" + + +// generated using utils/calc-76489an.py +const uint16_t frequencyCodes[8][12] = { + { 3420, 3229, 3047, 2876, 2715, 2562, 2419, 2283, 2155, 2034, 1920, 1812 }, + { 1710, 1614, 1524, 1438, 1357, 1281, 1209, 1141, 1077, 1017, 960, 906 }, + { 855, 807, 762, 719, 679, 641, 605, 571, 539, 508, 480, 453 }, + { 428, 404, 381, 360, 339, 320, 302, 285, 269, 254, 240, 226 }, + { 214, 202, 190, 180, 170, 160, 151, 143, 135, 127, 120, 113 }, + { 107, 101, 95, 90, 85, 80, 76, 71, 67, 64, 60, 57 }, + { 53, 50, 48, 45, 42, 40, 38, 36, 34, 32, 30, 28 }, + { 27, 25, 24, 22, 21, 20, 19, 18, 17, 16, 15, 14 } +}; + + +#define ADDR_DATA_REG P2OUT +#define BUS_CTRL_REG P1OUT +#define BUS_CTRL_IN_REG P1IN +#define _CS0 BIT0 +#define _CS1 BIT1 +#define _WE BIT2 +#define READY BIT3 + +#define CHANNEL_A_PERIOD_ADDR 0 +#define CHANNEL_A_ATTEN_ADDR 1 +#define CHANNEL_B_PERIOD_ADDR 2 +#define CHANNEL_B_ATTEN_ADDR 3 +#define CHANNEL_C_PERIOD_ADDR 4 +#define CHANNEL_C_ATTEN_ADDR 5 + +#define IGNORE_OCTET 0xff + +inline static void BEGIN_WRITE(uint8_t chipNo) { + if (chipNo == 0) { + BUS_CTRL_REG &= ~_CS0; + } else { + BUS_CTRL_REG &= ~_CS1; + } + + BUS_CTRL_REG &= ~_WE; +} + +inline static void END_WRITE(uint8_t chipNo) { + while ((BUS_CTRL_IN_REG & ~READY) == 0); + + BUS_CTRL_REG |= _WE; + + if (chipNo == 0) { + BUS_CTRL_REG |= _CS0; + } else { + BUS_CTRL_REG |= _CS1; + } +} + + + +static void psgWriteFrequency(uint8_t channel, uint16_t frequencyCode) { + uint8_t chipNo = channel / 3; + uint8_t channelAddr = (channel % 3) * 2; + + uint8_t firstOctet = 0x01 | (channelAddr << 1) | ((frequencyCode & 0x03c0) +} + +void psgPlayTone(uint8_t channel, t_octave octave, t_note note) { +} + +void psgAmplitude(uint8_t channel, uint8_t volume) { +} + +void psgInit() { + // address/data bus + P2DIR = 0xff; + P2SEL = 0; + P2SEL2 = 0; + + // bus control lines + // output: + // BIT0: /CS chip 0 + // BIT1: /CS chip 1 + // BIT2: /WE + // input: + // BIT3: READY + P1DIR |= BIT0 | BIT1 | BIT2; + P1DIR &= ~BIT3; + // immediately disable all outputs, all are active low + P1OUT |= BIT0 | BIT1 | BIT2; +} + diff --git a/sound-driver/utils/calc-76489an.py b/sound-driver/utils/calc-76489an.py new file mode 100644 index 0000000..e8ef518 --- /dev/null +++ b/sound-driver/utils/calc-76489an.py @@ -0,0 +1,64 @@ +N = 3579545.0 +factor = 1.0594631 +base = 440.0 + +frequencies = [] + +BEFORE_A = 46 +f = base +for i in range (BEFORE_A): + idx = BEFORE_A - i - 1 + print(f"{idx}: {f}") + frequencies.append(f) + f = base / factor + base = f +frequencies.reverse() + +AFTER_A = 50 +base = 440.0 +for i in range(AFTER_A): + idx = BEFORE_A + i + f = base * factor + print(f"{idx}: {f}") + frequencies.append(f) + base = f + +# print(f"{frequencies}") + +codes = [] +for i in range(len(frequencies)): + codes.append(round(N / (32.0 * frequencies[i]))) + + +#const uint16_t frequencyCodes[8][12] = { +# // C, Cis, D, Dis, E, F, Fis, G, Gis, A, Ais, H +# { 06535, 06234, 05747, 05474, 05233, 05002, 04563, 04353, 04153, 03762, 03600, 03424 }, // Octave 1 +# { 03256, 03116, 02764, 02636, 02515, 02401, 02271, 02165, 02065, 01771, 01700, 01612 }, // Octave 2 +# { 01527, 01447, 01372, 01317, 01247, 01201, 01135, 01073, 01033, 00774, 00740, 00705 }, // Octave 3 +# { 00654, 00624, 00575, 00550, 00523, 00500, 00456, 00435, 00415, 00376, 00360, 00342 }, // Octave 4 +# { 00326, 00312, 00276, 00264, 00252, 00240, 00227, 00217, 00207, 00177, 00170, 00161 }, // Octave 5 +# { 00153, 00145, 00137, 00132, 00125, 00120, 00114, 00107, 00103, 00100, 00074, 00071 }, // Octave 6 +# { 00065, 00062, 00060, 00055, 00052, 00050, 00046, 00044, 00042, 00040, 00036, 00034 }, // Octave 7 +# { 00033, 00031, 00030, 00026, 00025, 00024, 00023, 00022, 00021, 00020, 00017, 00016 } // Octave 8 +#}; + + + +print("const uint16_t frequencyCodes[8][12] = {") +step = 12 +for i in range(len(codes)): + if (i % step == 0): + print(" { ", end='') + print(f"{codes[i]}", end='') + if ((i+1) % step != 0): + print(", ", end='') + if ((i+1) % step == 0): + print(" }", end='') + if ((i+1) != len(codes)): + print(", ") + else: + print() +print("};") + + +