Conference ricks::dechips

::What it boils down to, is this:  Digital Semiconductor made a decision.
::EV56 is NOT a different generation.  It's just an EV5 with a faster clock
::cycle time.

   That's right, it's not a different generation.  It is, however,
   a different member of the family, one with unique characteristics,
   characteristics that need to be uniquely identified to customers,
   engineers, etc...

:   We (programmers, system builders, and custoemrs) have to be able to
:   tell the two apart, because no matter what the folks at DS say, the
:   EV5 and EV56 are different.  (Because I suspect we're going to wear
:   some egg for this decision otherwise, it would be very useful to hear
:   the party line around this particular decision.)

   Well, the first `egg' arrived here this morning...

   Quoting the customer question:

}Which Alpha (server)  models uses this ev56 CPU
}
}1    1000A           300 MHz?   333 MHz?  400 MHz???
}
}2    2000/2100A      250 MHz?   300 MHz?  (375 MHz???)
}
}3    4000/4100       All ????????????????????

   I looked in the SOC and -- guess what -- they're all listed as the
   `21164'.  Argh.

   --
/*
//  ALPHA_IMPLVER_AMASK_FEATURES.C
//  Retrieve the Alpha microprocessor family and features
//
//  Author: Steve Hoffman, Digital Equipment Corporation
//  [email protected], 16-Jan-1997.
//
//  DEC C V5 and later under OpenVMS. 
//  Also operates under DEC C on Digital UNIX V4.0 and later.
//
//  See the Alpha Architecture Reference Manual for the current
//  microprocessor family codes, as well as the instruction set
//  extension definition codes.
*/
#include <stdio.h>
#include <c_asm.h>
main()
    {
    int implver = asm("implver %r0;");
    int amask = asm("amask %a0,%r0;", -1 );
    int definedbits = 0;

    printf("Alpha Microprocessor Family:\n");
    /*
    //  The "microprocessor family" includes the named microprocessor,
    //  and various microprocessors (if any) derived from it.
    */
    printf("  DECchip 21%1.1d64 or variant\n", implver );
    printf("  (EV%1.1d microprocessor core)\n", implver + 4 );

    /*
    //  The bit is *clear* if the capability is *present*...
    */
    printf("Alpha extensions available:\n");
    if ( !~amask ) printf("  none.\n");
    definedbits |= 1L<<0;
    if ( ~amask & 1L<<0 ) printf("  byte-word, et al.\n");
    definedbits |= 1L<<1;
    if ( ~amask & 1L<<1 ) printf("  square root, et al.\n");
    definedbits |= 1L<<8;
    if ( ~amask & 1L<<8 ) printf("  Audio and video, et al.\n");
    if ( ~amask & ~definedbits ) printf("  Unknown capability bit present.");
    return 1;
    }