GPIO_VSYNC_UPDATE  122 core/usb_sync.c         *(volatile int*)(GPIO_VSYNC_UPDATE) = 1;
GPIO_VSYNC_UPDATE  124 core/usb_sync.c         while (*(volatile int*)(GPIO_VSYNC_UPDATE)) {}; // wait until the new value is applied
GPIO_VSYNC_UPDATE  129 core/usb_sync.c         *(volatile int*)(GPIO_VSYNC_UPDATE) = 1;