網路上查到的.參考一下: 7 T0 z! K* U+ } i7 y# M"Diffusion ROM is based on VT change (using VT implant mask) => Hihg VT transistors not conducting, low VT ones conducting 9 X0 B1 y1 f4 @+ F8 O" ~
VIA ROM is using via to "connect" or "not connect", resulting 0 and 1 - O2 I6 S& ]: H4 o* l8 f- u3 ^# J
VIA 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