EA

Library._EA · r1.1 · 19 Feb 2004 · guest

_EA (EA Prime) is a pin on the MCU that controls whether the MCU runs off Internal ROM or an external ROM chip.

_EA is pin 31 on 40-pin Intel8051 MCUs

J1 on OBD1 ECUs controls the state of _EA, and is used to activate an external ROM you install.