Hello,

I want to implement a system with the following elements :

- One P89C662 with 32 KB of Flash internal code memory (0000-7FFFH).
- One 32KB RAM between 0000-7FFFH for data, with Harvard addressing.
- One 32KB RAM between 8000H-FFFFH for code, with von Neumann addressing.

With /EA connected at VCC, the processor boots on his internal code.
/EA remains all time at VCC (with a sole sampling of /EA state at system boot).

Normaly, as all of MCS51 chips, outside of his own internal memory, it addresses
external memory (this point is unclear in Philips's 66X documents).
For ISP, I have planed a choice by jumper for P2.7, between VCC and A15
for in-system programming (following the schematic in Philips' datasheet).

If something is wrong in my understanding of /EA behavior in 89C662, or if
some connection is missing, I should be happy to read the advice of
experts before board making.

Thank you for your help and best regards,

J.M.