Hi,

Need I to pull up 8032's P0 when interfacing with
external memory (code, data, and I/O) ?

I've a 8032 design with external EPROM, SRAM,
and handful of I/O's - along with the address demuliplexer,
port 0 sums up to drive eight devices.

My question is whether I need to pull up the P0
externally ?

Although P0 is open collector, by the datasheets from
both Intel and Philips, when P0 serves as the muliplexed
address/data bus in an external memory orI/O accesses,
an internal pull up - a 'strong' one in Philips literature,
will be used when the bus emitting 1.

Then it seems that external pul-up is unnecessary.
But according to a Philips' application note AN457:
"80C51 External Memory Interfacing", the author
suggests: "P0 is open collector, so pull-up resistors
are typically required when interfacing to external
memory or I/O chips".

So what your typical experience ?

As I try to bump up CPU clock rate as high
as possible, and given with the large fanouts
in my design, additional pull-up will improve
bus performance, or make things worse ?

Any suggestions will be greatly appreciated.


Regards
M.H. Chou