In addition to the Lattice Semiconductor logo, and 1 or 2 lines of part-number marking, all Lattice devices contain a lot/date code marking.
The Lot/Date code format is "AYWWAAXX":
A=Lattice Internal Alpha Code
Y=Year of Inspection Lot Formation
WW=Work Week of Inspection Lot Formation
AA=Lattice Internal Alpha Codes
XX=Sequential Inspection Lot Number