Changeset ebc8f69 in buchla-emu for emu/cpu.c

Timestamp:

07/20/2017 08:18:39 PM (7 years ago)

Author:

Thomas Lopatic <thomas@…>

Branches:

master

Children:

4c71d39

Parents:

2147e53

Message:

Throttle CPU to 7 MHz.

File:

• emu/cpu.c (modified) (3 diffs)

emu/cpu.c

@@ -26 +26 @@
 bool cpu_verbose = false;
 
-#define CYCLES 70
+#define CPU_FREQ 7000000
+#define PER_SEC 100000
 
 #define APP_START 0x10000
@@ -450 +451 @@
         m68k_pulse_reset();
 
+        uint64_t freq = SDL_GetPerformanceFrequency();
+        uint64_t quan = freq / PER_SEC;
+        inf("freq %" PRIu64 " quan %" PRIu64, freq, quan);
+
         bool run = true;
 
         while (run) {
-                m68k_execute(CYCLES);
+                uint64_t until = SDL_GetPerformanceCounter() + quan;
+
+                m68k_execute(CPU_FREQ / PER_SEC);
                 hw_exec();
 
@@ -461 +468 @@
                         if (ev.type == SDL_QUIT) {
                                 run = false;
-                                break;
                         }
                 }
+
+                while (SDL_GetPerformanceCounter() < until) {
+                        _mm_pause();
+                }
         }