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
網路上查到的.參考一下: ; w8 g) a4 F3 o5 e0 |& x"Diffusion ROM is based on VT change (using VT implant mask) => Hihg VT transistors not conducting, low VT ones conducting - J, _# x$ }1 }
VIA ROM is using via to "connect" or "not connect", resulting 0 and 1 % `" K, Q( @" X! l# [
VIA ROM may have bigger cell size "