🚀 go-pugleaf

In article <8083@uklirb.informatik.uni-kl.de> kirchner@informatik.uni-kl.de (Reinhard Kirchner) writes:
>
>Months ago when the first discussions about the new MIPS R4000 processor
>where held here people from MIPS stated ( if I remember well ) that
>they will cross the limit of 32 bit addresses and be able to address a
>64 bit virtual address space.
>
>Now today I got a data sheet of the R4000 from IDT, and it does not only
>say anything about this, it also shows a block diagram with a 32 * 32 bit
>register set. So: will the R4000 really have 64 bit addresses and how
>can they be generated with 32 bit registers ?
>
>Maybe people from MIPS ( Mr. Mashey ? ) could shed some light on this ?

Since John Mashey is out of town...

First, let me point out that the R4000 is not an announced product.

Since the R4000 is NOT an announced product,
there are details that we are not supposed to talk about.
That means I can't give you a fully satisfying answer.
Sorry about that.

The R4000 has
  32 registers -- each 64 bits wide,
  generates and tests 64-bit virtual addresses.

The processor is able to execute existing 32-bit binary programs.
If you are executing an existing binary (i.e. "being compatible"),
your program will "see" registers and address space just like an R3000 --
32 registers each 32-bits wide,
virtual addresses 32 bits total with 31 bits for user space.

The processor will also execute programs with
virtual address spaces >32-bits that operate on 64-bit registers.

64-bit versus 32-bit operation is one of
the areas that I can't talk about in detail.
Sorry.

-- 
Charlie Price    cprice@mips.mips.com        (408) 720-1700
MIPS Computer Systems / 928 Arques Ave.  MS 1-03 / Sunnyvale, CA   94088-3650