I'm seeing at the link  that you get a NACK or Stop condition after transfer data.
Could you please elaborate more what you need. The guide of the Avalon I2C below for more information.
If the I2C Master Core gets a NACK when the device address is transmitted, how does it behave? Does it just set the MAK bit in the ISR? Does it issue a STOP? Does the driver need to issue the STOP or a repeated START?
If you follow the link  drives you to page 178 with some examples of transmitting or receiving data.
Also, you can see more information about the protocol, specifically NACK on the link  on page 5.