te . ▁ ▁Ant if use ▁– ▁One - time ▁program m able . ▁C M OS . ▁ ▁P ROM ▁– ▁Program m able ▁Read - Only ▁Memory ▁technology . ▁One - time ▁program m able ▁because ▁of ▁pl astic ▁pack aging . ▁Ob sole te . ▁ ▁EP ROM ▁– ▁Er as able ▁Program m able ▁Read - Only ▁Memory ▁technology . ▁One - time ▁program m able ▁but ▁with ▁window , ▁can ▁be ▁er ased ▁with ▁ult rav io let ▁( U V ) ▁light . ▁C M OS . ▁Ob sole te . ▁ ▁E EP ROM ▁– ▁Elect r ically ▁Er as able ▁Program m able ▁Read - Only ▁Memory ▁technology . ▁Can ▁be ▁er ased , ▁even ▁in ▁pl astic ▁packages . ▁Some ▁but ▁not ▁all ▁E EP ROM ▁devices ▁can ▁be ▁in - system ▁program med . ▁C M OS . ▁ ▁Flash ▁– ▁Flash - er ase ▁EP ROM ▁technology . ▁Can ▁be ▁er ased , ▁even ▁in ▁pl astic ▁packages . ▁Some ▁but ▁not ▁all ▁flash ▁devices ▁can ▁be ▁in - system ▁program med . ▁Usually , ▁a ▁flash ▁cell ▁is ▁smaller ▁than ▁an ▁equivalent ▁E EP ROM ▁cell ▁and ▁is ▁therefore ▁less ▁expensive ▁to ▁manufact ure . ▁C M OS . ▁ ▁Major ▁manufact ur ers ▁ ▁In ▁ 2 0 1 6 , ▁long - time ▁industry ▁riv als ▁X il inx ▁and ▁Al tera ▁( now ▁an ▁Intel ▁subs idi ary ) ▁were ▁the ▁F P GA ▁market ▁leaders . ▁At