This project is intended to be a software project but a description of the hardware is necessary as a reference to understand the resources available to the software.

Features

• Runs on Altera Cyclone IV and V FPGA Cards
• 68000 CPU
• 32 MB SDRAM
• Host Serial Connection (USB to Serial) 
• Video Display Unit (VDU)
  • VGA
  • PS/2 keyboard

FPGA Cards

• Initially running on Cyclone V FPGA card (very small resource utilization)
• Ported to Cyclone IV EP4CE15 FPGA card - compiled
• Resource efficient but probably wouldn't fit into anything smaller than an EP4CE10.

Flow Status    Successful - Sun Sep 06 12:05:04 2020
Quartus Prime Version    20.1.0 Build 711 06/05/2020 SJ Lite Edition
Revision Name            SOC
Top-level Entity Name    C5BoardToplevel
Family                   Cyclone IV E
Device                   EP4CE15F23C8
Timing Models            Final
Total logic elements     7,984 / 15,408 ( 52 % )
Total registers          3629
Total pins               134 / 344 ( 39 % )
Total virtual pins       0
Total memory bits        107,520 / 516,096 ( 21 % )
Embedded Mult 9-bit els  2 / 112 ( 2 % )
Total PLLs               1 / 4 ( 25 % )

TG 68000 Core

• 100 MHz?
• Wait states
• 32-bits of addresses connected?

32MB SDRAM

• Winbond W9825G6KH-6 133 SDRAM
• 4M x 16 bits x 4 banks

Host Serial Interface

• FT-230XS USB to Serial
  • 115200,N,8,1
• USB B connector

Video Display Unit

• VGA
• PS/2 keyboard and Mouse

Memory Map

• 0x00000000-0x0000FFFF = ROM
• 0x00100000 - Framebuffer
• 0x0FFFFA -  Variables
• 0x7FFFFE - The initial stack pointer
• 0x800000 = VGA controller
  • Screen base address register
• 0x810000 = Peripherals
  • Four counters, t0 through t3
  • 0x810010-0x810016 = Divisor register for all four counters
  • 0x81000e = Control word at which contains interrupt enable bits and status bits for counters t1 through t3.  
  • T0 acts as a prescalar for the other three timers, so with the system clock set to 112.5MHz, setting T0’s divisor to 1125 gives the other three timers a 100KHz base clock.
• 0x820000 = Audio controller