start with other sound chip

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));
 }

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_

sound-driver/sn76489an.c

@@ -0,0 +1,94 @@
+#include <msp430g2553.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#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;
+}
+

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("};")
+
+
+