Question I'm looking for a DIP-40 processor with 64-bit architecture ?

[The Floof]

Hello,
Not sure if it is possible, but is there a DIP-40 processor with a 64-bit architecture? I found 32-bit DIP-40s, but not 64-bit. Thank you.

 

[kerberos_20]

those 64bits would be for data bus, right?
probably not, because of added complexity, low pin count would make its I/O too slow i guess

 

[hotaru.hino]

It's possible, it'll just be really slow due to needing to spend multiple cycles on I/O. For instance if you were to have a pinout similar to the original 8086, you'd spend 4 cycles sending out the address, then another at least 4 cycles sending or receiving data.

EDIT: If you were looking at something like a Propeller CPU, then you'd still spend 2 cycles at least.

Also I realized with the address, I realized you can't really send out the address in multiple cycles because most things aren't designed to handle constructing the address through multiple cycles. If the ISA allows for a higher address space range than what you have for I/O, then the memory controller could just not send out the upper bits.

For anyone else wondering if what I'm saying is possible, examples of processors that internally are wider than their databus include the 8088 (16-bit CPU using an 8-bit data bus) and the Motorola 68K (32-bit CPU using an 16-bit data bus)

 

[CountMike]

Such CPU would be foot long and inch tall to accommodate all necessary pins and cache need to eleviate problem internal and external paths.

 

[hotaru.hino]

Such CPU would be foot long and inch tall to accommodate all necessary pins and cache need to eleviate problem internal and external paths.

It really depends on the ISA though. If you're talking about something as simple as a 8086 or 68K, but you're just widening the data path, then you can make that on a tiny footprint with even a 14nm process.