GPIO_VSYNC_MAX    107 core/usb_sync.c         int std_period = EngDrvRead(GPIO_VSYNC_MAX);
GPIO_VSYNC_MAX    121 core/usb_sync.c         *(volatile int*)(GPIO_VSYNC_MAX) = sync_period; // write the length of the extended period to the register
GPIO_VSYNC_MAX    128 core/usb_sync.c         *(volatile int*)(GPIO_VSYNC_MAX) = std_period; // back to standard timing on next period