網路上查到的.參考一下: " A+ n* M9 c5 V4 q# v& z3 Y# w6 T"Diffusion ROM is based on VT change (using VT implant mask) => Hihg VT transistors not conducting, low VT ones conducting 6 W2 Q( F% g$ V1 D. LVIA ROM is using via to "connect" or "not connect", resulting 0 and 1 7 k' R# [/ M( sVIA ROM may have bigger cell size "
Diffusion ROM通常用在exteranl ROM; Via ROM 跟metal ROM通常是應用在embedded system; Difussion ROM的應用時間是ROM code真的很成熟的時候,這樣才可以gain到體積小而不用改ROM code的優點; Via ROM更改ROM code的cost則比較小