Oki MSM85C154HVS - EA(CPU Memory Separate); Outline; External ROM Mode; Internal ROM Mode

MSM80C154S/83C154S/85C154HVS
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3.3 EA (CPU Memory Separate)
3.3.1 Outline
The function of the EA pin is to determine whether a CPU internal program memory (ROM)
instruction or an external program instruction is to be executed.
(1) Internal ROM mode
If the EA pin is connected to VCC and a “1” reset signal is applied to the RESET pin to
reset the CPU, an internal program memory (ROM) is executed from address 0.
(MSM83C154S, MSM85C154HVS)
(2) External ROM mode
If the EA pin is connected to VSS and a “1” reset signal is applied to the RESET pin to
reset the CPU, an external program memory is executed from address 0.