Thank you for contacting Cypress Semiconductor
I had verified with Product Engineering as well as from Process Development Engineering, in regards to the AM29DL640G70
and this is their response :
" We agree that the AM29DL640G70 units have been sandblasted, but not by Cypress. Therefore we cannot accept RMA or other
responsibility for the units. We are concerned that these AM29DL640G70 units might be re-marked / re-graded or counterfeit units "
Hope this helps...