Re: MAX Machine PLA equations (correct this time)

From: Michał Pleban <*lists_at_michau.name*> Date: Sun, 04 Sep 2016 16:49:49 +0200 Message-ID: <57CC348D.4020005@michau.name> · lists_at_michau.name

Hello!

Segher Boessenkool wrote:

> That looks very nice and simple, but how does this allow accesses from
> the VIC to RAM and ROM?  I don't see it; everything is only for CPU
> accesses (CLK & BA)?

I see that you have only first lines of the equations? Please take a
look at full ones:

!RAM = !A11 & !A12 & !A13 & !A14 & !A15 & CLK & BA
 # !A11 & !A12 & !A13 & !CLK
 # !A11 & !A12 & !A13 & !BA;

!EXRAM = A11 & !A12 & !A13 & !A14 & !A15 & CLK & BA
 # A11 & !A12 & !A13 & !CLK
 # A11 & !A12 & !A13 & !BA;

!ROMH = A13 & A14 & A15 & CLK & BA
 # A12 & A13 & !CLK
 # A12 & A13 & !BA;

The first line (CLK & BA) is for CPU access, the second anf third lines
(!CLK # !BA) is for VIC access.

Regards,
Michau.

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