I would like to know if the ALTERA FPGA(Cyclone) can directly connect to CODEC chip W6810(from Winbond) or not? The VoH-min of W6810 = 4.6V. If not, how to design the interface?
Re: help needed for Cyclone: interfacing with CODEC chip W68
The IO of Cyclone is 3.3V tolerance and cannot handle voltage higher than that. I would suggest that you use buffers in between such as the 'LVC series that are 5V tolerance. The buffer 74LVC16244 would be such a choice.