Re: 6510 CPU extensions

From: John (john_at_ucc.gu.uwa.edu.au)
Date: 2002-04-22 11:23:25

  • Next message: Gideon Zweijtzer: "RE: 6510 CPU extensions"
    Gideon Zweijtzer writes:
    
    >Some documentation on the 6510 states that the chip needs two
    >non-overlapping clocks. Ruud Baltissen pointed out that this is *NOT* true;
    >the CPU just outputs its input clock (PHI1) with some delay to the output
    >PHI2.
    
    Well, it's true and it's not true.  The 6510 uses dynamic logic (just read
    some of their patents from that time), which needs at least two phase
    non-overlapping.  But that's just internally.  You give it a single clock,
    and it generates the two phases from that.
    
    Your implementation won't be using dynamic logic, so there's no need for
    it.
    
    Now my memory fails me... the 6502 outputs the clock on a couple of pins,
    to feed to other devices that might need it.  Does the 6510 do the same?
    It might be polite to generate a clock, but since you've had this running
    in a real C64, it looks like it's not used anyway.
    
    John
    
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