best processor compatible with 80C52FA?

I need to upgrade the cpu in a system to get more memory, speed and
any other features that might be availble. The replacement cpu needs
to be pin compatible with the 80c51fa. I'm leaning toward the Dallas
89c450.  It has 64k of internal flash code memory, 1k of extra RAM,
and runs at 1 cycle per instruction (x12). The crystal that I'm
currently running is only 11 mhz. Would that be the best chioce for
memory, speed, availability?

thanks,
Wilfred

Like any question like this one, there may be other factors you need to 
look at.

1) What country are you in ??

	If Dallas does not sell there, it matters little if is a good choice, 
you will have to look for something else.

2) How fast do you need it, how much will it cost ??

	Dallas (maxim-ic.com) web site shows 18 week lead time for a 40-pin DIP 
and 19 week lead time for a TQFP. Cost is $9.51 for the DIP and $7,86 
for the TQFP ( in 1K pcs each).

If this is for a real product, contact Dallas/maxim-ic.com and ask for a 
sample. What is nice about the 80x51 family, is most (not all) parts 
will work in an existing design. ( after you take into account timing 
issues with the higher speed or higher through put.


The best answer in "try it".


Wilfred Johnson wrote:
> I need to upgrade the cpu in a system to get more memory, speed and
> any other features that might be availble. The replacement cpu needs
> to be pin compatible with the 80c51fa. I'm leaning toward the Dallas
> 89c450.  It has 64k of internal flash code memory, 1k of extra RAM,
> and runs at 1 cycle per instruction (x12). The crystal that I'm
> currently running is only 11 mhz. Would that be the best chioce for
> memory, speed, availability?
> 
> thanks,
> Wilfred
> 

Wilfred Johnson wrote:
> I need to upgrade the cpu in a system to get more memory, speed and
> any other features that might be availble. The replacement cpu needs
> to be pin compatible with the 80c51fa. I'm leaning toward the Dallas
> 89c450.  It has 64k of internal flash code memory, 1k of extra RAM,
> and runs at 1 cycle per instruction (x12). The crystal that I'm
> currently running is only 11 mhz. Would that be the best chioce for
> memory, speed, availability?

The FX core has many sources :
Dallas is the fastest, with std pinout, there are also

W78ERD2    - New from Winbond
AT89C51ED2 - Atmels newest variant
P89[L]V51  - Philips
SST89V55x  - SST

-jg