sound and extreme overclocking

xrip · Oct 6, 2023 · e5abfd9 · e5abfd9
1 parent 22b3fd3
commit e5abfd9
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Showing 3 changed files with 23 additions and 9 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -54,7 +54,9 @@ add_executable(sms
 
 pico_set_program_name(sms "sms Emulator for MURMULATOR devboard")
 pico_set_program_version(sms "v0.1")
-
+pico_define_boot_stage2(slower_boot2 ${PICO_DEFAULT_BOOT_STAGE2_FILE})
+target_compile_definitions(slower_boot2 PRIVATE PICO_FLASH_SPI_CLKDIV=4)
+pico_set_boot_stage2(${PROJECT_NAME} slower_boot2)
 
 target_include_directories(sms PRIVATE TotalSMS)
 

diff --git a/drivers/vga/vga_vmode.cpp b/drivers/vga/vga_vmode.cpp
@@ -211,8 +211,8 @@ void VgaCfgDef(sVgaCfg* cfg)
     cfg->height = 480;		// height in lines
     cfg->wfull = 0;			// width of full screen, corresponding to 'hfull' time (0=use 'width' parameter)
     cfg->video = &VideoVGA;		// used video timings
-    cfg->freq = 288000;       // required minimal system frequency in kHz (real frequency can be higher)
-    cfg->fmax = 288000;		// maximal system frequency in kHz (limit resolution if needed)
+    cfg->freq = 396*1000;       // required minimal system frequency in kHz (real frequency can be higher)
+    cfg->fmax = 396*1000;		// maximal system frequency in kHz (limit resolution if needed)
     cfg->dbly = False;		// double in Y direction
     cfg->lockfreq = True;		// lock required frequency, do not change it
 }

diff --git a/main.cpp b/main.cpp
@@ -15,7 +15,7 @@
 #include "pico/multicore.h"
 #include "sms.h"
 #include "vga.h"
-
+#define ENABLE_SOUND 1
 #if ENABLE_SOUND
 #include "audio.h"
 #endif
@@ -72,7 +72,7 @@ void load_cart_rom_file(char *filename) {
     FIL fil;
     FRESULT fr;
 
-    size_t bufsize = sizeof SCREEN;
+    size_t bufsize = sizeof(SCREEN)&0xfffff000;
     BYTE *buffer = (BYTE *) SCREEN;
     auto ofs = FLASH_TARGET_OFFSET;
 
@@ -207,6 +207,9 @@ void rom_file_selector() {
 //-----------------------------------------------------------------------------
 
 //-----------------------------------------------------------------------------
+        if ((nespad_state & DPAD_SELECT) != 0) {
+            break;
+        }
         if ((nespad_state & DPAD_A) != 0 || (nespad_state & DPAD_B) != 0 || (nespad_state & DPAD_START) != 0) {
             /* copy the rom from the SD card to flash and start the game */
             char pathname[255];
@@ -375,7 +378,7 @@ static void core_vblank_callback(void *user) {
 
 #if ENABLE_SOUND
 i2s_config_t i2s_config;
-#define AUDIO_FREQ (44100)
+#define AUDIO_FREQ (22050)
 #define SAMPLES 4096
 static struct SMS_ApuSample sms_audio_samples[SAMPLES];
 
@@ -388,12 +391,21 @@ __attribute__((always_inline)) inline void core_audio_callback(void* user, struc
 #endif
 
 int main() {
-    vreg_set_voltage(VREG_VOLTAGE_1_15);
-    set_sys_clock_khz(288000, true);
+    /* Overclock. */
+    hw_set_bits(&vreg_and_chip_reset_hw->vreg, VREG_AND_CHIP_RESET_VREG_VSEL_BITS);
+    sleep_ms(33);
+
+    set_sys_clock_khz(396 * 1000, true);
 
     gpio_init(PICO_DEFAULT_LED_PIN);
     gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
 
+    for (int i = 0; i < 6; i++) {
+        sleep_ms(33);
+        gpio_put(PICO_DEFAULT_LED_PIN, true);
+        sleep_ms(33);
+        gpio_put(PICO_DEFAULT_LED_PIN, false);
+    }
 #if !NDEBUG
     stdio_init_all();
 #endif
@@ -414,7 +426,7 @@ int main() {
 #if ENABLE_SOUND
     i2s_config = i2s_get_default_config();
     i2s_config.sample_freq = AUDIO_FREQ;
-    i2s_config.dma_trans_count = i2s_config.sample_freq / 20;
+    i2s_config.dma_trans_count = sizeof(sms_audio_samples)/sizeof(sms_audio_samples[0]);
     i2s_volume(&i2s_config, 0);
     i2s_init(&i2s_config);
     SMS_set_apu_callback(&sms, core_audio_callback, sms_audio_samples, sizeof(sms_audio_samples)/sizeof(sms_audio_samples[0]), AUDIO_FREQ);