Olin Lathrop <piclist@mit.edu> wrote:

> And by the way, one CBLOCK statement does not prevent other CBLOCK
> statements from assigning the same values to different symbols. 
> Each CBLOCK merely assigns sequential values to a list of symbols. 
> It has absolutely nothing to do with RAM allocation.
> ....
> It is not possible to RES the same memory location twice.

    Sure it is, if you use the UDATA_OVR directive... But you
    wouldn't do that accidentally, any more than you'd accidentally
    enumerate two CBLOCKs at the same value. 

    I didn't claim that CBLOCK was always preferable to RES, or that
    CBLOCK "allocates" RAM, or that CBLOCK always prevents
    reassignment of registers.  My only point was that the protection
    from reassignment provided by RES is NO BETTER than what CBLOCK
    offers: 

        a) EQUs trump both RES and CBLOCK equally,

        b) both CBLOCK and RES will allow registers to be reassigned
        if the right parameters are used, and

        c) if you don't use those parameters or EQUs, both CBLOCK and
        RES will keep registers from being reassigned. 

    -Andy

    P.S.  If I stipulate that there's nothing wrong with using
    relocatable mode assembly, will you stop characterizing all
    register-naming with EQU or CBLOCK as "boneheaded" and a
    "misuse"?  I hope so, because I'm tired and I REALLY don't want
    to spend an hour writing up examples to rebut that
    characterization. 

=== Andrew Warren -- aiw@cypress.com
=== Principal Design Engineer
=== Cypress Semiconductor Corporation
=== (but open to offers)
=== 
=== Opinions expressed above do not
=== necessarily represent those of
=== Cypress Semiconductor Corporation

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