-/*\r
- Skelton for retropc emulator\r
-\r
- Author : Takeda.Toshiya\r
- Date : 2006.08.18 -\r
-\r
- [ SN76489AN ]\r
-*/\r
-\r
-#include "sn76489an.h"\r
-#include "../fileio.h"\r
-\r
-#ifdef HAS_SN76489\r
-// SN76489\r
-#define NOISE_FB 0x4000\r
-#define NOISE_DST_TAP 1\r
-#define NOISE_SRC_TAP 2\r
-#else\r
-// SN76489A, SN76496\r
-#define NOISE_FB 0x10000\r
-#define NOISE_DST_TAP 4\r
-#define NOISE_SRC_TAP 8\r
-#endif\r
-#define NOISE_MODE ((regs[6] & 4) ? 1 : 0)\r
-\r
-void SN76489AN::initialize()\r
-{\r
- mute = false;\r
- cs = we = true;\r
-}\r
-\r
-void SN76489AN::reset()\r
-{\r
- for(int i = 0; i < 4; i++) {\r
- ch[i].count = 0;\r
- ch[i].period = 1;\r
- ch[i].volume = 0;\r
- ch[i].signal = false;\r
- }\r
- for(int i = 0; i < 8; i += 2) {\r
- regs[i + 0] = 0;\r
- regs[i + 1] = 0x0f; // volume = 0\r
- }\r
- noise_gen = NOISE_FB;\r
- ch[3].signal = false;\r
-}\r
-\r
-void SN76489AN::write_io8(uint32 addr, uint32 data)\r
-{\r
- if(data & 0x80) {\r
- index = (data >> 4) & 7;\r
- int c = index >> 1;\r
- \r
- switch(index & 7) {\r
- case 0: case 2: case 4:\r
- // tone : frequency\r
- regs[index] = (regs[index] & 0x3f0) | (data & 0x0f);\r
- ch[c].period = regs[index] ? regs[index] : 0x400;\r
-// ch[c].count = 0;\r
- break;\r
- case 1: case 3: case 5: case 7:\r
- // tone / noise : volume\r
- regs[index] = data & 0x0f;\r
- ch[c].volume = volume_table[data & 0x0f];\r
- break;\r
- case 6:\r
- // noise : frequency, mode\r
- regs[6] = data;\r
- data &= 3;\r
- ch[3].period = (data == 3) ? (ch[2].period << 1) : (1 << (data + 5));\r
-// ch[3].count = 0;\r
- noise_gen = NOISE_FB;\r
- ch[3].signal = false;\r
- break;\r
- }\r
- } else {\r
- int c = index >> 1;\r
- \r
- switch(index & 0x07) {\r
- case 0: case 2: case 4:\r
- // tone : frequency\r
- regs[index] = (regs[index] & 0x0f) | (((uint16)data << 4) & 0x3f0);\r
- ch[c].period = regs[index] ? regs[index] : 0x400;\r
-// ch[c].count = 0;\r
- // update noise shift frequency\r
- if(index == 4 && (regs[6] & 3) == 3) {\r
- ch[3].period = ch[2].period << 1;\r
- }\r
- break;\r
- }\r
- }\r
-}\r
-\r
-void SN76489AN::write_signal(int id, uint32 data, uint32 mask)\r
-{\r
- if(id == SIG_SN76489AN_MUTE) {\r
- mute = ((data & mask) != 0);\r
- } else if(id == SIG_SN76489AN_DATA) {\r
- val = data & mask;\r
- } else if(id == SIG_SN76489AN_CS) {\r
- bool next = ((data & mask) != 0);\r
- if(cs != next) {\r
- if(!(cs = next) && !we) {\r
- write_io8(0, val);\r
- }\r
- }\r
- } else if(id == SIG_SN76489AN_CS) {\r
- bool next = ((data & mask) != 0);\r
- if(cs != next) {\r
- cs = next;\r
- if(!cs && !we) {\r
- write_io8(0, val);\r
- }\r
- }\r
- } else if(id == SIG_SN76489AN_WE) {\r
- bool next = ((data & mask) != 0);\r
- if(we != next) {\r
- we = next;\r
- if(!cs && !we) {\r
- write_io8(0, val);\r
- }\r
- }\r
- }\r
-}\r
-\r
-void SN76489AN::mix(int32* buffer, int cnt)\r
-{\r
- if(mute) {\r
- return;\r
- }\r
- for(int i = 0; i < cnt; i++) {\r
- int32 vol = 0;\r
- for(int j = 0; j < 4; j++) {\r
- if(!ch[j].volume) {\r
- continue;\r
- }\r
- ch[j].count -= diff;\r
- if(ch[j].count < 0) {\r
- ch[j].count += ch[j].period << 8;\r
- if(j == 3) {\r
- if(((noise_gen & NOISE_DST_TAP) ? 1 : 0) ^ (((noise_gen & NOISE_SRC_TAP) ? 1 : 0) * NOISE_MODE)) {\r
- noise_gen >>= 1;\r
- noise_gen |= NOISE_FB;\r
- } else {\r
- noise_gen >>= 1;\r
- }\r
- ch[3].signal = ((noise_gen & 1) != 0);\r
- } else {\r
- ch[j].signal = !ch[j].signal;\r
- }\r
- }\r
- vol += ch[j].signal ? ch[j].volume : -ch[j].volume;\r
- }\r
- *buffer++ += vol; // L\r
- *buffer++ += vol; // R\r
- }\r
-}\r
-\r
-void SN76489AN::init(int rate, int clock, int volume)\r
-{\r
- // create gain\r
- double vol = volume;\r
- for(int i = 0; i < 15; i++) {\r
- volume_table[i] = (int)vol;\r
- vol /= 1.258925412;\r
- }\r
- volume_table[15] = 0;\r
- diff = 16 * clock / rate;\r
-}\r
-\r
-#define STATE_VERSION 1\r
-\r
-void SN76489AN::save_state(FILEIO* state_fio)\r
-{\r
- state_fio->FputUint32(STATE_VERSION);\r
- state_fio->FputInt32(this_device_id);\r
- \r
- state_fio->Fwrite(regs, sizeof(regs), 1);\r
- state_fio->FputInt32(index);\r
- state_fio->Fwrite(ch, sizeof(ch), 1);\r
- state_fio->FputUint32(noise_gen);\r
- state_fio->FputBool(mute);\r
- state_fio->FputBool(cs);\r
- state_fio->FputBool(we);\r
- state_fio->FputUint8(val);\r
-}\r
-\r
-bool SN76489AN::load_state(FILEIO* state_fio)\r
-{\r
- if(state_fio->FgetUint32() != STATE_VERSION) {\r
- return false;\r
- }\r
- if(state_fio->FgetInt32() != this_device_id) {\r
- return false;\r
- }\r
- state_fio->Fread(regs, sizeof(regs), 1);\r
- index = state_fio->FgetInt32();\r
- state_fio->Fwrite(ch, sizeof(ch), 1);\r
- noise_gen = state_fio->FgetUint32();\r
- mute = state_fio->FgetBool();\r
- cs = state_fio->FgetBool();\r
- we = state_fio->FgetBool();\r
- val = state_fio->FgetUint8();\r
- return true;\r
-}\r
-\r
+/*
+ Skelton for retropc emulator
+
+ Author : Takeda.Toshiya
+ Date : 2006.08.18 -
+
+ [ SN76489AN ]
+*/
+
+#include "sn76489an.h"
+#include "../fileio.h"
+
+#ifdef HAS_SN76489
+// SN76489
+#define NOISE_FB 0x4000
+#define NOISE_DST_TAP 1
+#define NOISE_SRC_TAP 2
+#else
+// SN76489A, SN76496
+#define NOISE_FB 0x10000
+#define NOISE_DST_TAP 4
+#define NOISE_SRC_TAP 8
+#endif
+#define NOISE_MODE ((regs[6] & 4) ? 1 : 0)
+
+void SN76489AN::initialize()
+{
+ mute = false;
+ cs = we = true;
+}
+
+void SN76489AN::reset()
+{
+ for(int i = 0; i < 4; i++) {
+ ch[i].count = 0;
+ ch[i].period = 1;
+ ch[i].volume = 0;
+ ch[i].signal = false;
+ }
+ for(int i = 0; i < 8; i += 2) {
+ regs[i + 0] = 0;
+ regs[i + 1] = 0x0f; // volume = 0
+ }
+ noise_gen = NOISE_FB;
+ ch[3].signal = false;
+}
+
+void SN76489AN::write_io8(uint32 addr, uint32 data)
+{
+ if(data & 0x80) {
+ index = (data >> 4) & 7;
+ int c = index >> 1;
+
+ switch(index & 7) {
+ case 0: case 2: case 4:
+ // tone : frequency
+ regs[index] = (regs[index] & 0x3f0) | (data & 0x0f);
+ ch[c].period = regs[index] ? regs[index] : 0x400;
+// ch[c].count = 0;
+ break;
+ case 1: case 3: case 5: case 7:
+ // tone / noise : volume
+ regs[index] = data & 0x0f;
+ ch[c].volume = volume_table[data & 0x0f];
+ break;
+ case 6:
+ // noise : frequency, mode
+ regs[6] = data;
+ data &= 3;
+ ch[3].period = (data == 3) ? (ch[2].period << 1) : (1 << (data + 5));
+// ch[3].count = 0;
+ noise_gen = NOISE_FB;
+ ch[3].signal = false;
+ break;
+ }
+ } else {
+ int c = index >> 1;
+
+ switch(index & 0x07) {
+ case 0: case 2: case 4:
+ // tone : frequency
+ regs[index] = (regs[index] & 0x0f) | (((uint16)data << 4) & 0x3f0);
+ ch[c].period = regs[index] ? regs[index] : 0x400;
+// ch[c].count = 0;
+ // update noise shift frequency
+ if(index == 4 && (regs[6] & 3) == 3) {
+ ch[3].period = ch[2].period << 1;
+ }
+ break;
+ }
+ }
+}
+
+void SN76489AN::write_signal(int id, uint32 data, uint32 mask)
+{
+ if(id == SIG_SN76489AN_MUTE) {
+ mute = ((data & mask) != 0);
+ } else if(id == SIG_SN76489AN_DATA) {
+ val = data & mask;
+ } else if(id == SIG_SN76489AN_CS) {
+ bool next = ((data & mask) != 0);
+ if(cs != next) {
+ if(!(cs = next) && !we) {
+ write_io8(0, val);
+ }
+ }
+ } else if(id == SIG_SN76489AN_CS) {
+ bool next = ((data & mask) != 0);
+ if(cs != next) {
+ cs = next;
+ if(!cs && !we) {
+ write_io8(0, val);
+ }
+ }
+ } else if(id == SIG_SN76489AN_WE) {
+ bool next = ((data & mask) != 0);
+ if(we != next) {
+ we = next;
+ if(!cs && !we) {
+ write_io8(0, val);
+ }
+ }
+ }
+}
+
+void SN76489AN::mix(int32* buffer, int cnt)
+{
+ if(mute) {
+ return;
+ }
+ for(int i = 0; i < cnt; i++) {
+ int32 vol = 0;
+ for(int j = 0; j < 4; j++) {
+ if(!ch[j].volume) {
+ continue;
+ }
+ ch[j].count -= diff;
+ if(ch[j].count < 0) {
+ ch[j].count += ch[j].period << 8;
+ if(j == 3) {
+ if(((noise_gen & NOISE_DST_TAP) ? 1 : 0) ^ (((noise_gen & NOISE_SRC_TAP) ? 1 : 0) * NOISE_MODE)) {
+ noise_gen >>= 1;
+ noise_gen |= NOISE_FB;
+ } else {
+ noise_gen >>= 1;
+ }
+ ch[3].signal = ((noise_gen & 1) != 0);
+ } else {
+ ch[j].signal = !ch[j].signal;
+ }
+ }
+ vol += ch[j].signal ? ch[j].volume : -ch[j].volume;
+ }
+ *buffer++ += vol; // L
+ *buffer++ += vol; // R
+ }
+}
+
+void SN76489AN::init(int rate, int clock, int volume)
+{
+ // create gain
+ double vol = volume;
+ for(int i = 0; i < 15; i++) {
+ volume_table[i] = (int)vol;
+ vol /= 1.258925412;
+ }
+ volume_table[15] = 0;
+ diff = 16 * clock / rate;
+}
+
+#define STATE_VERSION 1
+
+void SN76489AN::save_state(FILEIO* state_fio)
+{
+ state_fio->FputUint32(STATE_VERSION);
+ state_fio->FputInt32(this_device_id);
+
+ state_fio->Fwrite(regs, sizeof(regs), 1);
+ state_fio->FputInt32(index);
+ state_fio->Fwrite(ch, sizeof(ch), 1);
+ state_fio->FputUint32(noise_gen);
+ state_fio->FputBool(mute);
+ state_fio->FputBool(cs);
+ state_fio->FputBool(we);
+ state_fio->FputUint8(val);
+}
+
+bool SN76489AN::load_state(FILEIO* state_fio)
+{
+ if(state_fio->FgetUint32() != STATE_VERSION) {
+ return false;
+ }
+ if(state_fio->FgetInt32() != this_device_id) {
+ return false;
+ }
+ state_fio->Fread(regs, sizeof(regs), 1);
+ index = state_fio->FgetInt32();
+ state_fio->Fwrite(ch, sizeof(ch), 1);
+ noise_gen = state_fio->FgetUint32();
+ mute = state_fio->FgetBool();
+ cs = state_fio->FgetBool();
+ we = state_fio->FgetBool();
+ val = state_fio->FgetUint8();
+ return true;
+}
+
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