網路上查到的.參考一下:1 j$ [8 g9 V: D0 c9 C
"Diffusion ROM is based on VT change (using VT implant mask) => Hihg VT transistors not conducting, low VT ones conducting * I/ X# M8 \; b' }3 ?
VIA ROM is using via to "connect" or "not connect", resulting 0 and 1 ' y' @3 H% d& V5 q7 w4 X+ G, K
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