Diff: apu.cpp

Revision:

0:5bd52e196edb

Child:

1:02a06cd10a33

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/apu.cpp	Mon Jan 09 13:54:39 2017 +0000
@@ -0,0 +1,206 @@
+/* hwapu - SPC music playback tools for real snes apu
+ * Copyright (C) 2004-2005  Raphael Assenat <raph@raphnet.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+#include <stdio.h>
+#include <string.h>
+#include "apu.h"
+#include <time.h>
+// #include <sys/time.h>
+#include "mbed.h"
+
+
+//#define TRACE_RW
+
+extern int g_verbose; // from main.c
+
+/******************** G L O B A L S ************************************/
+static int port0=0;
+static APU_ops *apu_ops = NULL;
+
+void apu_setOps(APU_ops *ops)
+{
+    apu_ops = ops;
+}
+
+static int SetPort0 (short data)
+{
+    port0=data;
+    return 0;
+}
+
+void apu_write (int address, unsigned char data)
+{
+//#ifdef TRACE_RW
+//  printf("apu_write: a=%d, %02x\n", address, data);
+//#endif
+    apu_ops->write(address, data);  
+}
+
+unsigned char apu_read (int address)
+{
+    unsigned char tmp = apu_ops->read(address);
+//#ifdef TRACE_RW
+//  printf("apu_read: a=%d -> %02x\n", address, tmp);
+//#endif
+
+    return tmp;
+}
+
+/* Write to address 'address', write the previously
+ * read value from port0 back to port 0 and wait
+ * for port0 value to be different from the written one.
+ */
+int apu_writeHandshake(int address, int data)
+{
+//  int i;
+//  i = 0;
+    apu_write(address, data);
+    apu_write(0,port0);
+    
+    if (!apu_waitInport(0, port0, 500)) {
+        return 1;
+    }
+    port0++;
+    if (port0 == 256)
+        port0 = 0;
+
+    return 0;
+    
+
+}
+
+
+int apu_writeBytes(unsigned char *data, int len)
+{
+    int i;
+#ifdef TRACE_RW
+    printf("apu_writeBytes: %d...\n", len);
+#endif
+    for (i=0; i<len; i++) {
+        if (apu_writeHandshake(1, data[i])) { return 1; }
+    }
+    return 0;
+}
+
+void apu_reset(void)    //Reset the APU by whatever means it needs reset.
+{
+    apu_ops->reset();   
+
+}
+
+/* return false on timeout, otherwise true */
+int apu_waitInport(int port, unsigned char data, int timeout_ms)
+{
+    // struct timeval tv_before, tv_now;
+    // gettimeofday(&tv_before, NULL);
+    int elaps_milli;
+    Timer t;
+    t.start();
+
+#ifdef TRACE_RW
+    printf("apu_waitInport: addr: %d, data: %02x\n",port,data);
+#endif
+    
+    while(apu_read(port)!=data) {
+        //usleep(1);
+//        gettimeofday(&tv_now, NULL);
+//        elaps_milli = (tv_now.tv_sec - tv_before.tv_sec) * 1000;
+//        elaps_milli += (tv_now.tv_usec-tv_before.tv_usec)/1000;
+        elaps_milli = t.read_ms();
+        if (elaps_milli > timeout_ms )
+        {
+            if (g_verbose) 
+                printf("timeout after %d milli\n", elaps_milli);
+            return 0;
+        }
+    }
+    return 1;
+}
+
+int apu_initTransfer(unsigned short address)
+{
+    /* Initializing the transfer */
+    /* Wait for port 2140 to be $aa */
+    if (!apu_waitInport(0, 0xaa, 500)) {
+        if (g_verbose) 
+            printf("Should read 0xaa, but reads %02x\n", apu_read(0));
+        return -1;
+    }
+    /* and Wait for port 2141 to be $bb */
+    if (!apu_waitInport(1, 0xbb, 500)) {
+        if (g_verbose) 
+            printf("Should read 0xaa, but reads %02x\n", apu_read(0));
+        return -1;
+    }
+    /* The spc is now ready */
+
+    /* Write any value other than 0 to 2141 */
+    apu_write(1, 1);
+    /* Write the destination address to poirt $2142 and $2143, with the
+     * low byte written at $2142 */
+    apu_write(2, address&0xff); // low
+    apu_write(3, (address&0xff00)>>8); // high So our code will go at $0002
+    /* Write $CC to port $2140 */
+    apu_write(0, 0xCC);
+
+    /* Wait for $2140 to be $CC */
+    if (!apu_waitInport(0, 0xcc, 500)) {
+        if (g_verbose) 
+            printf("Should read 0xcc, but reads %02x\n", apu_read(0));
+        return -1;
+    }
+
+    SetPort0(0);
+    
+    return 0;
+}
+
+int apu_newTransfer(unsigned short address)
+{
+    int i;
+    apu_write(1,1);
+    apu_write(3, (address&0xff00)>>8);
+    apu_write(2, (address & 0xff));
+
+    i = apu_read(0);
+    i += 2; i &= 0xff;
+    if (!i) { i += 2; } // if it's 0, increase it again
+    apu_write(0, i);
+    if (!apu_waitInport(0, i, 500)) {
+        fprintf(stderr, "apu_newTransfer: timeout\n"); return -1;
+    }
+    
+    SetPort0(0);
+    
+    return 0;
+}
+
+void apu_endTransfer(unsigned short start_address)
+{
+    int i;
+    
+    apu_write(1, 0);
+    apu_write(3, (start_address & 0xff00)>>8);
+    apu_write(2, (start_address & 0xff));
+
+    i = apu_read(0);
+    i +=2; i &= 0xff;
+    if (!i) { i+=2 ; } // if it's 0, increase it again
+    apu_write(0, i);
+}
+
+