Difference between AR9227 and AR9287 chipsets

[malepati vishnuvardhan]

Hi,
As i am doing some research on atheros drivers of freebsd. I want to know,
if Atheros AR9227 and AR9287 are same??  As i didnt find any datasheet
regarding atheros AR9227. So, please guide me to find the data sheet of
AR9227,if its different from AR9287.

Thanks and Regards,
vishnu