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Re: FPGA motherboard for 80386 CPU

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Den fredag den 10. november 2017 kl. 21.20.02 UTC+1 skrev Rick C. Hodgin:
> On Friday, November 10, 2017 at 2:46:34 PM UTC-5, rickman wrote:
> > Rick C. Hodgin wrote on 11/10/2017 10:35 AM:
> > > The 80386DX CPU had 132 pins:
> > >
> > >     80386DX and 80386SX pinouts:
> > >     http://www.rfwireless-world.com/images/80386-pin-diagram.jpg
> > >     https://image.slidesharecdn.com/salientfeatursof80386-140822084001-phpapp02/95/salient-featurs-of-80386-14-638.jpg?cb=1408709884
> > >
> > >     General architecture:
> > >     http://www.nptel.ac.in/courses/Webcourse-contents/IISc-BANG/Microprocessors%20and%20Microcontrollers/pdf/Teacher_Slides/mod8/M8L1.pdf
> > >
> > > Of these pins on the DX variant:
> > >
> > >     32 pins -- data
> > >     30 pins -- address
> > >      4 pins -- byte enables in 32-bit writes
> > >      1 pin  -- Read/write
> > >      1 pin  -- Data/Control
> > >      1 pin  -- Memory/IO
> > >      1 pin  -- Bus mastering lock issued by CPU
> > >      1 pin  -- Bus16 size (16-bit when asserted, normally 32-bit)
> > >      1 pin  -- Next address (for pipelining)
> > >      1 pin  -- Address valid signal
> > >     --
> > >     73 pins -- For basic I/O
> > >
> > >      3 pins -- Math-coprocessor support
> > >      1 pin  -- Ready (or Wait, for bus cycles to complete)
> > >      2 pins -- Hold and Hold Acknowledge (for bus mastering)
> > >      2 pins -- Interrupt and Non-masktable Interrupt
> > >     --
> > >      8 pins -- General coordination with external peripherals
> > >
> > >      1 pin  -- Reset
> > >      1 pin  -- Double-pumped clock
> > >     --
> > >      2 pins -- System input
> > >
> > > The rest of the pins are unused, go to VSS or VCC.  This means that for a
> > > full 80386 "motherboard" only 83 pins are required to fully support its
> > > operation, 67 of which are address, data, and data type, leaving really
> > > only 15 pins of complex operation for a state machine.
> > >
> > > -----
> > > Would anybody be able to help me create this 80386 motherboard using an
> > > AMD Am386 CPU, which is a static CPU operating from 0 to 40 MHz?  I would
> > > like to get it working with a single-step operation for design validation,
> > > and then to begin ramping it up.
> > >
> > > I figure I'll have an area of ROM which the CPU boots to load, which is a
> > > tiny real mode program, which begins computing something that can be exam-
> > > ined by the FPGA to test successful operation.  And then move on to more
> > > complex operations, including a custom microkernel.
> > 
> > I'm sure many here would be *able* to help you.  The question you should be 
> > asking is who would be *willing* to help you...
> > 
> > What parts are you having trouble with?  Why do you need help exactly?
> 
> The 80386DX was a 5V part.  My FPGA supports 3.3V, so I need some 
> kind of level shifter?  I'll need to build a breakout board to route 
> through my existing 40-pin FPGA breakout ports (160 pins).  So, do 
> I go with an online custom manufacturer?  Buy materials and pattern 
> and etch my own board, soldering everything myself?  Are there generic 
> sockets the Am386 would fit in which are already broken out?
> 
> I need help with the mechanics of Verilog.  I know how I want things 
> to route, but the mechanics of the language confuse me.  I don't
> understand why at times I need registers, and other times I can
> route wires.  The assignments are confusing me, when to use <= and
> when not to, etc.

then you should probably start with a basic verilog project with some blinking leds and not a giant hairball of a CISC cpu...

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FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-10 07:35 -0800
  Re: FPGA motherboard for 80386 CPU rickman <gnuarm@gmail.com> - 2017-11-10 14:46 -0500
    Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-10 12:19 -0800
      Re: FPGA motherboard for 80386 CPU rickman <gnuarm@gmail.com> - 2017-11-10 16:11 -0500
        Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-10 14:14 -0800
          Re: FPGA motherboard for 80386 CPU rickman <gnuarm@gmail.com> - 2017-11-10 18:31 -0500
            Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-10 15:59 -0800
              Re: FPGA motherboard for 80386 CPU rickman <gnuarm@gmail.com> - 2017-11-10 22:15 -0500
                Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-10 20:16 -0800
                Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-11 10:43 -0800
      Re: FPGA motherboard for 80386 CPU lasselangwadtchristensen@gmail.com - 2017-11-10 13:15 -0800
        Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-10 14:02 -0800
          Re: FPGA motherboard for 80386 CPU lasselangwadtchristensen@gmail.com - 2017-11-13 08:28 -0800
            Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-13 08:49 -0800
              Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-13 09:33 -0800
              Re: FPGA motherboard for 80386 CPU lasselangwadtchristensen@gmail.com - 2017-11-13 11:47 -0800
                Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-13 11:54 -0800
                Re: FPGA motherboard for 80386 CPU lasselangwadtchristensen@gmail.com - 2017-11-13 12:06 -0800
                Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-11-13 12:15 -0800
                Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-12-21 01:33 -0800
                Re: FPGA motherboard for 80386 CPU Richard Damon <Richard@Damon-Family.org> - 2017-12-22 19:23 -0500
                Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-12-24 14:04 -0800
                Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-12-20 05:49 -0800
  Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-12-12 12:10 -0800
    Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-12-14 06:29 -0800
  Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-12-28 07:32 -0800
    Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-12-30 09:54 -0800
      Re: FPGA motherboard for 80386 CPU Richard Damon <Richard@Damon-Family.org> - 2017-12-30 15:18 -0500
        Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-12-31 00:20 -0800
          Re: FPGA motherboard for 80386 CPU Emilian Miron <emilian.miron@gmail.com> - 2017-12-31 07:20 -0800
            Re: FPGA motherboard for 80386 CPU "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-12-31 13:52 -0800

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