Display frame counter and USB frame counter values at frame draw time. More...
Data Fields | |
uint16_t | display_frame_counter |
Counter that is incremented once per frame draw, i.e. nominally every 40ms. | |
uint16_t | usb_frame_counter |
Value of the USB frame counter when the frame is drawn, providing a common ms time base for all USB display devices on the same USB bus. | |
Display frame counter and USB frame counter values at frame draw time.
Upon frame timer roll-over, the USB frame counter value is latched such that a comparison can be made between multiple devices as to when they are drawing frames relative to each other. If different devices are in phase, then the diffence between the usb frame counter values should be an exact multiple of 40 (i.e. 40 ms or 25 FPS), with the factor of 40 being the difference between the display frame counters.